diff --git a/scheme/ikarus.apply.ss b/scheme/ikarus.apply.ss
index e215e09..a98124a 100644
--- a/scheme/ikarus.apply.ss
+++ b/scheme/ikarus.apply.ss
@@ -25,8 +25,8 @@
     (let ()
       (define (err f ls)
         (if (procedure? f)
-            (error 'apply "not a list" ls)
-            (error 'apply "not a procedure" f)))
+            (die 'apply "not a list" ls)
+            (die 'apply "not a procedure" f)))
       (define (fixandgo f a0 a1 ls p d)
         (cond
           [(null? ($cdr d))
diff --git a/scheme/ikarus.boot.prebuilt b/scheme/ikarus.boot.prebuilt
index fbb7d5b..017da69 100644
Binary files a/scheme/ikarus.boot.prebuilt and b/scheme/ikarus.boot.prebuilt differ
diff --git a/scheme/ikarus.bytevectors.ss b/scheme/ikarus.bytevectors.ss
index 3fc9742..e83748d 100644
--- a/scheme/ikarus.bytevectors.ss
+++ b/scheme/ikarus.bytevectors.ss
@@ -88,18 +88,18 @@
       [(k) 
        (if (and (fixnum? k) ($fx>= k 0))
            ($make-bytevector k)
-           (error 'make-bytevector "not a valid size" k))]
+           (die 'make-bytevector "not a valid size" k))]
       [(k fill)
        (if (and (fixnum? fill) ($fx<= -128 fill) ($fx<= fill 255))
            ($bytevector-fill (make-bytevector k) 0 k fill)
-           (error 'make-bytevector "not a valid fill" fill))]))
+           (die 'make-bytevector "not a valid fill" fill))]))
 
   (define bytevector-fill!
     (lambda (x fill)
       (unless (bytevector? x)
-        (error 'bytevector-fill! "not a bytevector" x))
+        (die 'bytevector-fill! "not a bytevector" x))
       (unless (and (fixnum? fill) ($fx<= -128 fill) ($fx<= fill 255))
-        (error 'bytevector-fill! "not a valid fill" fill))
+        (die 'bytevector-fill! "not a valid fill" fill))
       ($bytevector-fill x 0 ($bytevector-length x) fill)))
 
 
@@ -107,23 +107,23 @@
     (lambda (x)
       (if (bytevector? x)
           ($bytevector-length x)
-          (error 'bytevector-length "not a bytevector" x))))
+          (die 'bytevector-length "not a bytevector" x))))
 
   (define bytevector-s8-ref
     (lambda (x i)
       (if (bytevector? x)
           (if (and (fixnum? i) ($fx<= 0 i) ($fx< i ($bytevector-length x)))
               ($bytevector-s8-ref x i)
-              (error 'bytevector-s8-ref "invalid index" i x))
-          (error 'bytevector-s8-ref "not a bytevector" x))))
+              (die 'bytevector-s8-ref "invalid index" i x))
+          (die 'bytevector-s8-ref "not a bytevector" x))))
 
   (define bytevector-u8-ref
     (lambda (x i)
       (if (bytevector? x)
           (if (and (fixnum? i) ($fx<= 0 i) ($fx< i ($bytevector-length x)))
               ($bytevector-u8-ref x i)
-              (error 'bytevector-u8-ref "invalid index" i x))
-          (error 'bytevector-u8-ref "not a bytevector" x))))
+              (die 'bytevector-u8-ref "invalid index" i x))
+          (die 'bytevector-u8-ref "not a bytevector" x))))
 
 
   (define bytevector-s8-set!
@@ -132,9 +132,9 @@
           (if (and (fixnum? i) ($fx<= 0 i) ($fx< i ($bytevector-length x)))
               (if (and (fixnum? v) ($fx<= -128 v) ($fx<= v 127)) 
                   ($bytevector-set! x i v)
-                  (error 'bytevector-s8-set! "not a byte" v))
-              (error 'bytevector-s8-set! "invalid index" i x))
-          (error 'bytevector-s8-set! "not a bytevector" x))))
+                  (die 'bytevector-s8-set! "not a byte" v))
+              (die 'bytevector-s8-set! "invalid index" i x))
+          (die 'bytevector-s8-set! "not a bytevector" x))))
   
   (define bytevector-u8-set!
     (lambda (x i v)
@@ -142,9 +142,9 @@
           (if (and (fixnum? i) ($fx<= 0 i) ($fx< i ($bytevector-length x)))
               (if (and (fixnum? v) ($fx<= 0 v) ($fx<= v 255))
                   ($bytevector-set! x i v)
-                  (error 'bytevector-u8-set! "not an octet" v))
-              (error 'bytevector-u8-set! "invalid index" i x))
-          (error 'bytevector-u8-set! "not a bytevector" x))))
+                  (die 'bytevector-u8-set! "not an octet" v))
+              (die 'bytevector-u8-set! "invalid index" i x))
+          (die 'bytevector-u8-set! "not a bytevector" x))))
 
   (define bytevector-u16-native-ref ;;; HARDCODED
     (lambda (x i) 
@@ -156,8 +156,8 @@
               ($fxlogor
                 ($fxsll ($bytevector-u8-ref x i) 8)
                 ($bytevector-u8-ref x ($fxadd1 i)))
-              (error 'bytevector-u16-native-ref "invalid index" i))
-          (error 'bytevector-u16-native-ref "not a bytevector" x))))
+              (die 'bytevector-u16-native-ref "invalid index" i))
+          (die 'bytevector-u16-native-ref "not a bytevector" x))))
 
   
   (define bytevector-u16-native-set! ;;; HARDCODED
@@ -173,9 +173,9 @@
                   (begin
                     ($bytevector-set! x i ($fxsra n 8)) 
                     ($bytevector-set! x ($fxadd1 i) n))
-                  (error 'bytevector-u16-native-set! "invalid index" i))
-              (error 'bytevector-u16-native-set! "invalid value" n))
-          (error 'bytevector-u16-native-set! "not a bytevector" x))))
+                  (die 'bytevector-u16-native-set! "invalid index" i))
+              (die 'bytevector-u16-native-set! "invalid value" n))
+          (die 'bytevector-u16-native-set! "not a bytevector" x))))
 
   (define bytevector-s16-native-set! ;;; HARDCODED
     (lambda (x i n) 
@@ -190,9 +190,9 @@
                   (begin
                     ($bytevector-set! x i ($fxsra n 8)) 
                     ($bytevector-set! x ($fxadd1 i) n))
-                  (error 'bytevector-s16-native-set! "invalid index" i))
-              (error 'bytevector-s16-native-set! "invalid value" n))
-          (error 'bytevector-s16-native-set! "not a bytevector" x))))
+                  (die 'bytevector-s16-native-set! "invalid index" i))
+              (die 'bytevector-s16-native-set! "invalid value" n))
+          (die 'bytevector-s16-native-set! "not a bytevector" x))))
 
   (define bytevector-s16-native-ref ;;; HARDCODED
     (lambda (x i) 
@@ -204,8 +204,8 @@
               ($fxlogor
                 ($fxsll ($bytevector-s8-ref x i) 8)
                 ($bytevector-u8-ref x ($fxadd1 i)))
-              (error 'bytevector-s16-native-ref "invalid index" i))
-          (error 'bytevector-s16-native-ref "not a bytevector" x))))
+              (die 'bytevector-s16-native-ref "invalid index" i))
+          (die 'bytevector-s16-native-ref "not a bytevector" x))))
 
   (define bytevector-u16-ref
     (lambda (x i end) 
@@ -222,9 +222,9 @@
                  ($fxlogor
                    ($fxsll ($bytevector-u8-ref x (fxadd1 i)) 8)
                    ($bytevector-u8-ref x i))]
-                [else (error 'bytevector-u16-ref "invalid endianness" end)])
-              (error 'bytevector-u16-ref "invalid index" i))
-          (error 'bytevector-u16-ref "not a bytevector" x))))
+                [else (die 'bytevector-u16-ref "invalid endianness" end)])
+              (die 'bytevector-u16-ref "invalid index" i))
+          (die 'bytevector-u16-ref "not a bytevector" x))))
 
   (define bytevector-u32-ref
     (lambda (x i end) 
@@ -247,9 +247,9 @@
                       ($fxlogor
                         ($fxsll ($bytevector-u8-ref x ($fx+ i 1)) 8)
                         ($bytevector-u8-ref x i))))]
-                [else (error 'bytevector-u32-ref "invalid endianness" end)])
-              (error 'bytevector-u32-ref "invalid index" i))
-          (error 'bytevector-u32-ref "not a bytevector" x))))
+                [else (die 'bytevector-u32-ref "invalid endianness" end)])
+              (die 'bytevector-u32-ref "invalid index" i))
+          (die 'bytevector-u32-ref "not a bytevector" x))))
 
   (define bytevector-u32-native-ref
     (lambda (x i) 
@@ -264,8 +264,8 @@
                    ($fxlogor 
                      ($fxsll ($bytevector-u8-ref x ($fx+ i 2)) 8)
                      ($bytevector-u8-ref x ($fx+ i 3)))))
-              (error 'bytevector-u32-native-ref "invalid index" i))
-          (error 'bytevector-u32-native-ref "not a bytevector" x))))
+              (die 'bytevector-u32-native-ref "invalid index" i))
+          (die 'bytevector-u32-native-ref "not a bytevector" x))))
 
   (define bytevector-s32-ref
     (lambda (x i end) 
@@ -288,9 +288,9 @@
                       ($fxlogor
                         ($fxsll ($bytevector-u8-ref x ($fx+ i 1)) 8)
                         ($bytevector-u8-ref x i))))]
-                [else (error 'bytevector-s32-ref "invalid endianness" end)])
-              (error 'bytevector-s32-ref "invalid index" i))
-          (error 'bytevector-s32-ref "not a bytevector" x))))
+                [else (die 'bytevector-s32-ref "invalid endianness" end)])
+              (die 'bytevector-s32-ref "invalid index" i))
+          (die 'bytevector-s32-ref "not a bytevector" x))))
 
   (define bytevector-s32-native-ref
     (lambda (x i) 
@@ -305,8 +305,8 @@
                    ($fxlogor 
                      ($fxsll ($bytevector-u8-ref x ($fx+ i 2)) 8)
                      ($bytevector-u8-ref x ($fx+ i 3)))))
-              (error 'bytevector-s32-native-ref "invalid index" i))
-          (error 'bytevector-s32-native-ref "not a bytevector" x))))
+              (die 'bytevector-s32-native-ref "invalid index" i))
+          (die 'bytevector-s32-native-ref "not a bytevector" x))))
 
   (define bytevector-u16-set!
     (lambda (x i n end) 
@@ -324,10 +324,10 @@
                     [(little) 
                      ($bytevector-set! x i n)
                      ($bytevector-set! x ($fxadd1 i) (fxsra n 8))]
-                    [else (error 'bytevector-u16-ref "invalid endianness" end)])
-                  (error 'bytevector-u16-set! "invalid index" i))
-              (error 'bytevector-u16-set! "invalid value" n))
-          (error 'bytevector-u16-set! "not a bytevector" x))))
+                    [else (die 'bytevector-u16-ref "invalid endianness" end)])
+                  (die 'bytevector-u16-set! "invalid index" i))
+              (die 'bytevector-u16-set! "invalid value" n))
+          (die 'bytevector-u16-set! "not a bytevector" x))))
 
 
   (define bytevector-u32-set!
@@ -356,10 +356,10 @@
                      (let ([b (bitwise-and n #xFFFF)])
                        ($bytevector-set! x ($fx+ i 1) ($fxsra b 8))
                        ($bytevector-set! x i b))]
-                    [else (error 'bytevector-u32-ref "invalid endianness" end)])
-                  (error 'bytevector-u32-set! "invalid index" i))
-              (error 'bytevector-u32-set! "invalid value" n))
-          (error 'bytevector-u32-set! "not a bytevector" x))))
+                    [else (die 'bytevector-u32-ref "invalid endianness" end)])
+                  (die 'bytevector-u32-set! "invalid index" i))
+              (die 'bytevector-u32-set! "invalid value" n))
+          (die 'bytevector-u32-set! "not a bytevector" x))))
 
   (define bytevector-u32-native-set!
     (lambda (x i n) 
@@ -380,9 +380,9 @@
                     (let ([b (bitwise-and n #xFFFF)])
                       ($bytevector-set! x ($fx+ i 2) ($fxsra b 8))
                       ($bytevector-set! x ($fx+ i 3) b)))
-                  (error 'bytevector-u32-native-set! "invalid index" i))
-              (error 'bytevector-u32-native-set! "invalid value" n))
-          (error 'bytevector-u32-native-set! "not a bytevector" x))))
+                  (die 'bytevector-u32-native-set! "invalid index" i))
+              (die 'bytevector-u32-native-set! "invalid value" n))
+          (die 'bytevector-u32-native-set! "not a bytevector" x))))
 
 
   (define bytevector-s32-native-set!
@@ -404,9 +404,9 @@
                     (let ([b (bitwise-and n #xFFFF)])
                       ($bytevector-set! x ($fx+ i 2) ($fxsra b 8))
                       ($bytevector-set! x ($fx+ i 3) b)))
-                  (error 'bytevector-s32-native-set! "invalid index" i))
-              (error 'bytevector-s32-native-set! "invalid value" n))
-          (error 'bytevector-s32-native-set! "not a bytevector" x))))
+                  (die 'bytevector-s32-native-set! "invalid index" i))
+              (die 'bytevector-s32-native-set! "invalid value" n))
+          (die 'bytevector-s32-native-set! "not a bytevector" x))))
 
   (define bytevector-s32-set!
     (lambda (x i n end) 
@@ -434,10 +434,10 @@
                      (let ([b (bitwise-and n #xFFFF)])
                        ($bytevector-set! x ($fx+ i 1) ($fxsra b 8))
                        ($bytevector-set! x i b))]
-                    [else (error 'bytevector-s32-ref "invalid endianness" end)])
-                  (error 'bytevector-s32-set! "invalid index" i))
-              (error 'bytevector-s32-set! "invalid value" n))
-          (error 'bytevector-s32-set! "not a bytevector" x))))
+                    [else (die 'bytevector-s32-ref "invalid endianness" end)])
+                  (die 'bytevector-s32-set! "invalid index" i))
+              (die 'bytevector-s32-set! "invalid value" n))
+          (die 'bytevector-s32-set! "not a bytevector" x))))
 
   (define bytevector-s16-ref
     (lambda (x i end) 
@@ -454,9 +454,9 @@
                  ($fxlogor
                    ($fxsll ($bytevector-s8-ref x (fxadd1 i)) 8)
                    ($bytevector-u8-ref x i))]
-                [else (error 'bytevector-s16-ref "invalid endianness" end)])
-              (error 'bytevector-s16-ref "invalid index" i))
-          (error 'bytevector-s16-ref "not a bytevector" x))))
+                [else (die 'bytevector-s16-ref "invalid endianness" end)])
+              (die 'bytevector-s16-ref "invalid index" i))
+          (die 'bytevector-s16-ref "not a bytevector" x))))
 
   (define bytevector-s16-set!
     (lambda (x i n end) 
@@ -474,15 +474,15 @@
                     [(little) 
                      ($bytevector-set! x i n)
                      ($bytevector-set! x ($fxadd1 i) (fxsra n 8))]
-                    [else (error 'bytevector-s16-ref "invalid endianness" end)])
-                  (error 'bytevector-s16-set! "invalid index" i))
-              (error 'bytevector-s16-set! "invalid value" n))
-          (error 'bytevector-s16-set! "not a bytevector" x))))
+                    [else (die 'bytevector-s16-ref "invalid endianness" end)])
+                  (die 'bytevector-s16-set! "invalid index" i))
+              (die 'bytevector-s16-set! "invalid value" n))
+          (die 'bytevector-s16-set! "not a bytevector" x))))
 
   (define bytevector->u8-list
     (lambda (x)
       (unless (bytevector? x)
-        (error 'bytevector->u8-list "not a bytevector" x))
+        (die 'bytevector->u8-list "not a bytevector" x))
       (let f ([x x] [i ($bytevector-length x)] [ac '()])
         (cond
           [($fx= i 0) ac]
@@ -498,13 +498,13 @@
                       (if (pair? h)
                           (if (not (eq? h t))
                               (race ($cdr h) ($cdr t) ls ($fx+ n 2))
-                              (error 'u8-list->bytevector "circular list" ls))
+                              (die 'u8-list->bytevector "circular list" ls))
                           (if (null? h)
                               ($fx+ n 1)
-                              (error 'u8-list->bytevector "not a proper list" ls))))
+                              (die 'u8-list->bytevector "not a proper list" ls))))
                    (if (null? h)
                        n
-                       (error 'u8-list->bytevector "not a proper list" ls))))]
+                       (die 'u8-list->bytevector "not a proper list" ls))))]
               [fill
                (lambda (s i ls)
                  (cond
@@ -512,7 +512,7 @@
                    [else
                     (let ([c ($car ls)])
                       (unless (and (fixnum? c) ($fx<= 0 c) ($fx<= c 255))
-                        (error 'u8-list->bytevector "not an octet" c))
+                        (die 'u8-list->bytevector "not an octet" c))
                       ($bytevector-set! s i c)
                       (fill s ($fxadd1 i) (cdr ls)))]))])
        (lambda (ls)
@@ -523,7 +523,7 @@
   (define bytevector-copy
     (lambda (src)
       (unless (bytevector? src)
-        (error 'bytevector-copy "not a bytevector" src))
+        (die 'bytevector-copy "not a bytevector" src))
       (let ([n ($bytevector-length src)])
         (let f ([src src] [dst ($make-bytevector n)] [i 0] [n n])
           (cond
@@ -535,9 +535,9 @@
   (define bytevector=? 
     (lambda (x y)
       (unless (bytevector? x)
-        (error 'bytevector=? "not a bytevector" x))
+        (die 'bytevector=? "not a bytevector" x))
       (unless (bytevector? y)
-        (error 'bytevector=? "not a bytevector" y))
+        (die 'bytevector=? "not a bytevector" y))
       (let ([n ($bytevector-length x)])
         (and ($fx= n ($bytevector-length y))
              (let f ([x x] [y y] [i 0] [n n])
@@ -550,21 +550,21 @@
     (lambda (src src-start dst dst-start k) 
       (cond
         [(or (not (fixnum? src-start)) ($fx< src-start 0))
-         (error 'bytevector-copy! "not a valid starting index" src-start)]
+         (die 'bytevector-copy! "not a valid starting index" src-start)]
         [(or (not (fixnum? dst-start)) ($fx< dst-start 0))
-         (error 'bytevector-copy! "not a valid starting index" dst-start)]
+         (die 'bytevector-copy! "not a valid starting index" dst-start)]
         [(or (not (fixnum? k)) ($fx< k 0))
-         (error 'bytevector-copy! "not a valid length" k)]
+         (die 'bytevector-copy! "not a valid length" k)]
         [(not (bytevector? src)) 
-         (error 'bytevector-copy! "not a bytevector" src)]
+         (die 'bytevector-copy! "not a bytevector" src)]
         [(not (bytevector? dst)) 
-         (error 'bytevector-copy! "not a bytevector" dst)]
+         (die 'bytevector-copy! "not a bytevector" dst)]
         [(let ([n ($fx+ src-start k)])
            (or ($fx< n 0) ($fx> n ($bytevector-length src))))
-         (error 'bytevector-copy! "out of range" src-start k)]
+         (die 'bytevector-copy! "out of range" src-start k)]
         [(let ([n ($fx+ dst-start k)])
            (or ($fx< n 0) ($fx> n ($bytevector-length dst))))
-         (error 'bytevector-copy! "out of range" dst-start k)]
+         (die 'bytevector-copy! "out of range" dst-start k)]
         [(eq? src dst)
          (cond
            [($fx< dst-start src-start)
@@ -672,33 +672,33 @@
     (define bytevector-sint-ref
       (lambda (x k endianness size)
         (define who 'bytevector-sint-ref)
-        (unless (bytevector? x) (error who "not a bytevector" x))
-        (unless (and (fixnum? k) ($fx>= k 0)) (error who "invalid index" k))
-        (unless (and (fixnum? size) ($fx>= size 1)) (error who "invalid size" size))
+        (unless (bytevector? x) (die who "not a bytevector" x))
+        (unless (and (fixnum? k) ($fx>= k 0)) (die who "invalid index" k))
+        (unless (and (fixnum? size) ($fx>= size 1)) (die who "invalid size" size))
         (let ([n ($bytevector-length x)])
-          (unless ($fx< k n) (error who "index is out of range" k))
+          (unless ($fx< k n) (die who "index is out of range" k))
           (let ([end ($fx+ k size)])
             (unless (and ($fx>= end 0) ($fx<= end n))
-              (error who "out of range" k size))
+              (die who "out of range" k size))
             (case endianness
               [(little) (sref-little x k end)]
               [(big)    (sref-big x k end)]
-              [else (error who "invalid endianness" endianness)])))))
+              [else (die who "invalid endianness" endianness)])))))
     (define bytevector-uint-ref
       (lambda (x k endianness size)
         (define who 'bytevector-uint-ref)
-        (unless (bytevector? x) (error who "not a bytevector" x))
-        (unless (and (fixnum? k) ($fx>= k 0)) (error who "invalid index" k))
-        (unless (and (fixnum? size) ($fx>= size 1)) (error who "invalid size" size))
+        (unless (bytevector? x) (die who "not a bytevector" x))
+        (unless (and (fixnum? k) ($fx>= k 0)) (die who "invalid index" k))
+        (unless (and (fixnum? size) ($fx>= size 1)) (die who "invalid size" size))
         (let ([n ($bytevector-length x)])
-          (unless ($fx< k n) (error who "index is out of range" k))
+          (unless ($fx< k n) (die who "index is out of range" k))
           (let ([end ($fx+ k size)])
             (unless (and ($fx>= end 0) ($fx<= end n))
-              (error who "out of range" k size))
+              (die who "out of range" k size))
             (case endianness
               [(little) (uref-little x k end)]
               [(big)    (uref-big x k end)]
-              [else (error who "invalid endianness" endianness)])))))
+              [else (die who "invalid endianness" endianness)])))))
     (define (bytevector->some-list x k n ls proc who)
       (cond
         [($fx= n 0) ls]
@@ -708,36 +708,36 @@
              [($fx>= i 0)
               (bytevector->some-list x k i (cons (proc x i n) ls) proc who)]
              [else
-              (error who "invalid size" k)]))]))
+              (die who "invalid size" k)]))]))
     (define bytevector->uint-list
       (lambda (x endianness size)
         (define who 'bytevector->uint-list)
-        (unless (bytevector? x) (error who "not a bytevector" x))
-        (unless (and (fixnum? size) ($fx>= size 1)) (error who "invalid size" size))
+        (unless (bytevector? x) (die who "not a bytevector" x))
+        (unless (and (fixnum? size) ($fx>= size 1)) (die who "invalid size" size))
         (case endianness
           [(little) (bytevector->some-list x size ($bytevector-length x)
                       '() uref-little 'bytevector->uint-list)]
           [(big)    (bytevector->some-list x size ($bytevector-length x) 
                       '() uref-big 'bytevector->uint-list)]
-          [else (error who "invalid endianness" endianness)])))
+          [else (die who "invalid endianness" endianness)])))
     (define bytevector->sint-list
       (lambda (x endianness size)
         (define who 'bytevector->sint-list)
-        (unless (bytevector? x) (error who "not a bytevector" x))
-        (unless (and (fixnum? size) ($fx>= size 1)) (error who "invalid size" size))
+        (unless (bytevector? x) (die who "not a bytevector" x))
+        (unless (and (fixnum? size) ($fx>= size 1)) (die who "invalid size" size))
         (case endianness
           [(little) (bytevector->some-list x size ($bytevector-length x)
                       '() sref-little 'bytevector->sint-list)]
           [(big)    (bytevector->some-list x size ($bytevector-length x) 
                       '() sref-big 'bytevector->sint-list)]
-          [else (error who "invalid endianness" endianness)]))))
+          [else (die who "invalid endianness" endianness)]))))
 
   (module (bytevector-uint-set! bytevector-sint-set!)
     (define (lufx-set! x k1 n k2 who no)
       (cond
         [($fx= k1 k2) 
          (unless ($fxzero? n)
-           (error who "number does not fit" no))]
+           (die who "number does not fit" no))]
         [else
          (lufx-set! x ($fxadd1 k1) ($fxsra n 8) k2 who no)
          ($bytevector-set! x k1 ($fxlogand n 255))]))
@@ -745,7 +745,7 @@
       (cond
         [($fx= k1 k2) 
          (unless ($fx= n -1) ;;; BUG: does not catch all errors
-           (error who "number does not fit" no))]
+           (die who "number does not fit" no))]
         [else
          (lsfx-set! x ($fxadd1 k1) ($fxsra n 8) k2 who no)
          ($bytevector-set! x k1 ($fxlogand n 255))]))
@@ -753,7 +753,7 @@
       (cond
         [($fx= k1 k2) 
          (unless ($fxzero? n)
-           (error who "number does not fit" no))]
+           (die who "number does not fit" no))]
         [else
          (let ([k2 ($fxsub1 k2)])
            (bufx-set! x k1 ($fxsra n 8) k2 who no)
@@ -762,7 +762,7 @@
       (cond
         [($fx= k1 k2) 
          (unless ($fx= n -1)
-           (error who "number does not fit" no))]
+           (die who "number does not fit" no))]
         [else
          (let ([k2 ($fxsub1 k2)])
            (bsfx-set! x k1 ($fxsra n 8) k2 who no)
@@ -790,8 +790,8 @@
              [(#x00) ;;; borrow is 0, last byte was positive
               (if ($fx< xi xj)
                   (bv-neg-zero! x xi xj)
-                  (error who "number does not fit" n))]
-             [else (error 'lbn-neg-copy! "BUG: not handled" c)])]
+                  (die who "number does not fit" n))]
+             [else (die 'lbn-neg-copy! "BUG: not handled" c)])]
           [else
            (let ([c ($fx- ($fx+ 255 ($fxsra c 8)) ($bignum-byte-ref n ni))])
              (lbn-neg-copy! x ($fxadd1 xi) n ($fxadd1 ni) xj nj c)
@@ -807,8 +807,8 @@
              [(#x00) ;;; borrow is 0, last byte was positive
               (if ($fx< xi xj)
                   (bv-neg-zero! x xi xj)
-                  (error who "number does not fit" n))]
-             [else (error 'bbn-neg-copy! "BUG: not handled" c)])]
+                  (die who "number does not fit" n))]
+             [else (die 'bbn-neg-copy! "BUG: not handled" c)])]
           [else
            (let ([c ($fx- ($fx+ 255 ($fxsra c 8)) ($bignum-byte-ref n ni))]
                  [xj ($fxsub1 xj)])
@@ -824,7 +824,7 @@
               ;;; last byte was positive
               (bv-zero! x xi xj)]
              [else 
-              (error who "number does not fit" n)])]
+              (die who "number does not fit" n)])]
           [else
            (let ([c ($bignum-byte-ref n ni)])
              (lbn-pos-copy! x ($fxadd1 xi) n ($fxadd1 ni) nj xj c)
@@ -839,7 +839,7 @@
               ;;; last byte was positive
               (bv-zero! x xi xj)]
              [else 
-              (error who "number does not fit" n)])]
+              (die who "number does not fit" n)])]
           [else
            (let ([c ($bignum-byte-ref n ni)]
                  [xj ($fxsub1 xj)])
@@ -860,16 +860,16 @@
                       (if ($fxzero? ($bignum-byte-ref n i-3))
                           (let ([i-4 ($fxsub1 i-3)])
                             (if ($fxzero? ($bignum-byte-ref n i-4))
-                                (error 'bignum-bytes "BUG: malformed bignum")
+                                (die 'bignum-bytes "BUG: malformed bignum")
                                 i-3))
                           i-2))
                     i-1))
               i))))
     (define (make-bytevector-uint-set! who)
       (lambda (x k n endianness size)
-        (unless (bytevector? x) (error who "not a bytevector" x))
-        (unless (and (fixnum? k) ($fx>= k 0)) (error who "invalid index" k))
-        (unless (and (fixnum? size) ($fx>= size 1)) (error who "invalid size" size))
+        (unless (bytevector? x) (die who "not a bytevector" x))
+        (unless (and (fixnum? k) ($fx>= k 0)) (die who "invalid index" k))
+        (unless (and (fixnum? size) ($fx>= size 1)) (die who "invalid size" size))
         (case endianness
           [(little)
            (cond
@@ -883,9 +883,9 @@
                       [($fx< sz size)
                        (lbn-copy! x k n 0 sz)
                        (bv-zero! x ($fx+ k sz) ($fx+ k size))]
-                      [else (error who "number does not fit" n)]))
-                  (error who "value must be positive" n))]
-             [else (error who "invalid value argument" n)])]
+                      [else (die who "number does not fit" n)]))
+                  (die who "value must be positive" n))]
+             [else (die who "invalid value argument" n)])]
           [(big)
            (cond
              [(fixnum? n) (bufx-set! x k n ($fx+ k size) who n)]
@@ -898,10 +898,10 @@
                       [($fx< sz size)
                        (bbn-copy! x ($fx+ k size) n 0 sz)
                        (bv-zero! x k ($fx+ k ($fx- size sz)))]
-                      [else (error who "number does not fit" n)]))
-                  (error who "value must be positive" n))]
-             [else (error who "invalid value argument" n)])]
-          [else (error who "invalid endianness" endianness)])))
+                      [else (die who "number does not fit" n)]))
+                  (die who "value must be positive" n))]
+             [else (die who "invalid value argument" n)])]
+          [else (die who "invalid endianness" endianness)])))
     (define bytevector-uint-set! (make-bytevector-uint-set! 'bytevector-uint-set!))
     (define (make-bytevector-sint-set! who)
       (define bbn-neg-copy! (make-bbn-neg-copy! who))
@@ -909,9 +909,9 @@
       (define lbn-neg-copy! (make-lbn-neg-copy! who))
       (define lbn-pos-copy! (make-lbn-pos-copy! who))
       (lambda (x k n endianness size)
-        (unless (bytevector? x) (error who "not a bytevector" x))
-        (unless (and (fixnum? k) ($fx>= k 0)) (error who "invalid index" k))
-        (unless (and (fixnum? size) ($fx>= size 1)) (error who "invalid size" size))
+        (unless (bytevector? x) (die who "not a bytevector" x))
+        (unless (and (fixnum? k) ($fx>= k 0)) (die who "invalid index" k))
+        (unless (and (fixnum? size) ($fx>= size 1)) (die who "invalid size" size))
         (case endianness
           [(little)
            (cond
@@ -922,13 +922,13 @@
                     (cond
                       [($fx<= sz size) 
                        (lbn-pos-copy! x k n 0 size sz 255)]
-                      [else (error who "number does not fit" n)]))
+                      [else (die who "number does not fit" n)]))
                   (let ([sz (bignum-bytes n)])
                     (cond
                       [($fx<= sz size) 
                        (lbn-neg-copy! x k n 0 size sz 256)]
-                      [else (error who "number does not fit" n)])))]
-             [else (error who "invalid value argument" n)])]
+                      [else (die who "number does not fit" n)])))]
+             [else (die who "invalid value argument" n)])]
           [(big)
            (cond
              [(fixnum? n) (bsfx-set! x k n ($fx+ k size) who n)]
@@ -938,14 +938,14 @@
                     (cond
                       [($fx<= sz size) 
                        (bbn-pos-copy! x k n 0 size sz 255)]
-                      [else (error who "number does not fit" n)]))
+                      [else (die who "number does not fit" n)]))
                   (let ([sz (bignum-bytes n)])
                     (cond
                       [($fx<= sz size) 
                        (bbn-neg-copy! x k n 0 size sz 256)]
-                      [else (error who "number does not fit" n)])))] 
-             [else (error who "invalid value argument" n)])]
-          [else (error who "invalid endianness" endianness)])))
+                      [else (die who "number does not fit" n)])))] 
+             [else (die who "invalid value argument" n)])]
+          [else (die who "invalid endianness" endianness)])))
     (define bytevector-sint-set! (make-bytevector-sint-set! 'bytevector-sint-set!)))
 
   (module (uint-list->bytevector sint-list->bytevector)
@@ -961,15 +961,15 @@
                          (bv-set! bv idx a endianness size)
                          (bv-set! bv ($fx+ idx size) ($car h) endianness size)
                          bv)
-                       (error who "circular list" ls))
+                       (die who "circular list" ls))
                    (if (null? h)
                        (let ([bv (make-bytevector ($fx+ idx size))])
                          (bv-set! bv idx a endianness size)
                          bv)
-                       (error who "not a proper list" ls))))
+                       (die who "not a proper list" ls))))
             (if (null? h)
                 (make-bytevector idx)
-                (error who "not a proper list" ls))))
+                (die who "not a proper list" ls))))
       (lambda (ls endianness size)
         (race ls ls ls 0 endianness size)))
     (define uint-list->bytevector 
@@ -986,8 +986,8 @@
                  ($fxzero? ($fxlogand i 7))
                  ($fx< i ($bytevector-length bv)))
             ($bytevector-ieee-double-native-ref bv i)
-            (error 'bytevector-ieee-double-native-ref "invalid index" i))
-        (error 'bytevector-ieee-double-native-ref "not a bytevector" bv)))
+            (die 'bytevector-ieee-double-native-ref "invalid index" i))
+        (die 'bytevector-ieee-double-native-ref "not a bytevector" bv)))
 
   (define (bytevector-ieee-single-native-ref bv i)
     (if (bytevector? bv) 
@@ -996,8 +996,8 @@
                  ($fxzero? ($fxlogand i 3))
                  ($fx< i ($bytevector-length bv)))
             ($bytevector-ieee-single-native-ref bv i)
-            (error 'bytevector-ieee-single-native-ref "invalid index" i))
-        (error 'bytevector-ieee-single-native-ref "not a bytevector" bv)))
+            (die 'bytevector-ieee-single-native-ref "invalid index" i))
+        (die 'bytevector-ieee-single-native-ref "not a bytevector" bv)))
 
   (define (bytevector-ieee-double-native-set! bv i x) 
     (if (bytevector? bv) 
@@ -1007,9 +1007,9 @@
                  ($fx< i ($bytevector-length bv)))
             (if (flonum? x) 
                 ($bytevector-ieee-double-native-set! bv i x)
-                (error 'bytevector-ieee-double-native-set! "not a flonum" x))
-            (error 'bytevector-ieee-double-native-set! "invalid index" i))
-        (error 'bytevector-ieee-double-native-set! "not a bytevector" bv)))
+                (die 'bytevector-ieee-double-native-set! "not a flonum" x))
+            (die 'bytevector-ieee-double-native-set! "invalid index" i))
+        (die 'bytevector-ieee-double-native-set! "not a bytevector" bv)))
    
   (define (bytevector-ieee-single-native-set! bv i x) 
     (if (bytevector? bv) 
@@ -1019,9 +1019,9 @@
                  ($fx< i ($bytevector-length bv)))
             (if (flonum? x) 
                 ($bytevector-ieee-single-native-set! bv i x)
-                (error 'bytevector-ieee-single-native-set! "not a flonum" x))
-            (error 'bytevector-ieee-single-native-set! "invalid index" i))
-        (error 'bytevector-ieee-single-native-set! "not a bytevector" bv)))
+                (die 'bytevector-ieee-single-native-set! "not a flonum" x))
+            (die 'bytevector-ieee-single-native-set! "invalid index" i))
+        (die 'bytevector-ieee-single-native-set! "not a bytevector" bv)))
 
   (define (bytevector-ieee-double-ref bv i endianness) 
     (if (bytevector? bv) 
@@ -1032,10 +1032,10 @@
             (case endianness
               [(little) ($bytevector-ieee-double-native-ref bv i)]
               [(big) ($bytevector-ieee-double-nonnative-ref bv i)]
-              [else (error 'bytevector-ieee-double-ref 
+              [else (die 'bytevector-ieee-double-ref 
                       "invalid endianness" endianness)])
-            (error 'bytevector-ieee-double-ref "invalid index" i))
-        (error 'bytevector-ieee-double-ref "not a bytevector" bv)))
+            (die 'bytevector-ieee-double-ref "invalid index" i))
+        (die 'bytevector-ieee-double-ref "not a bytevector" bv)))
 
   (define (bytevector-ieee-single-ref bv i endianness) 
     (if (bytevector? bv) 
@@ -1046,10 +1046,10 @@
             (case endianness
               [(little) ($bytevector-ieee-single-native-ref bv i)]
               [(big) ($bytevector-ieee-single-nonnative-ref bv i)]
-              [else (error 'bytevector-ieee-single-ref 
+              [else (die 'bytevector-ieee-single-ref 
                       "invalid endianness" endianness)])
-            (error 'bytevector-ieee-single-ref "invalid index" i))
-        (error 'bytevector-ieee-single-ref "not a bytevector" bv)))
+            (die 'bytevector-ieee-single-ref "invalid index" i))
+        (die 'bytevector-ieee-single-ref "not a bytevector" bv)))
 
   (define (bytevector-ieee-double-set! bv i x endianness) 
     (if (bytevector? bv) 
@@ -1061,11 +1061,11 @@
                 (case endianness
                   [(little) ($bytevector-ieee-double-native-set! bv i x)]
                   [(big) ($bytevector-ieee-double-nonnative-set! bv i x)]
-                  [else (error 'bytevector-ieee-double-set! 
+                  [else (die 'bytevector-ieee-double-set! 
                           "invalid endianness" endianness)])
-                (error 'bytevector-ieee-double-set! "not a flonum" x))
-            (error 'bytevector-ieee-double-set! "invalid index" i))
-        (error 'bytevector-ieee-double-set! "not a bytevector" bv)))
+                (die 'bytevector-ieee-double-set! "not a flonum" x))
+            (die 'bytevector-ieee-double-set! "invalid index" i))
+        (die 'bytevector-ieee-double-set! "not a bytevector" bv)))
 
   (define (bytevector-ieee-single-set! bv i x endianness) 
     (if (bytevector? bv) 
@@ -1077,11 +1077,11 @@
                 (case endianness
                   [(little) ($bytevector-ieee-single-native-set! bv i x)]
                   [(big) ($bytevector-ieee-single-nonnative-set! bv i x)]
-                  [else (error 'bytevector-ieee-single-set! 
+                  [else (die 'bytevector-ieee-single-set! 
                           "invalid endianness" endianness)])
-                (error 'bytevector-ieee-single-set! "not a flonum" x))
-            (error 'bytevector-ieee-single-set! "invalid index" i))
-        (error 'bytevector-ieee-single-set! "not a bytevector" bv)))
+                (die 'bytevector-ieee-single-set! "not a flonum" x))
+            (die 'bytevector-ieee-single-set! "invalid index" i))
+        (die 'bytevector-ieee-single-set! "not a bytevector" bv)))
 
 
   (define ($bytevector-ref/64 bv i who decoder endianness)
@@ -1093,9 +1093,9 @@
             (case endianness
               [(little big) 
                (decoder bv i endianness 8)]
-              [else (error who "invalid endianness" endianness)])
-            (error who "invalid index" i))
-        (error who "not a bytevector" bv)))
+              [else (die who "invalid endianness" endianness)])
+            (die who "invalid index" i))
+        (die who "not a bytevector" bv)))
 
   (define (bytevector-u64-native-ref bv i) 
     ($bytevector-ref/64 bv i 'bytevector-u64-native-ref 
@@ -1119,17 +1119,17 @@
             (case endianness
               [(little big) 
                (unless (or (fixnum? n) (bignum? n))
-                 (error who 
+                 (die who 
                    (if (number? n) 
                        "number is not exact" 
                        "not a number")
                    n))
                (unless (and (<= lo n) (< n hi))
-                 (error who "number out of range" n))
+                 (die who "number out of range" n))
                (setter bv i n endianness 8)]
-              [else (error who "invalid endianness" endianness)])
-            (error who "invalid index" i))
-        (error who "not a bytevector" bv)))
+              [else (die who "invalid endianness" endianness)])
+            (die who "invalid index" i))
+        (die who "not a bytevector" bv)))
 
   (define (bytevector-u64-native-set! bv i n) 
     ($bytevector-set/64 bv i n 0 (expt 2 64)
diff --git a/scheme/ikarus.cafe.ss b/scheme/ikarus.cafe.ss
index 188660c..7525ec4 100644
--- a/scheme/ikarus.cafe.ss
+++ b/scheme/ikarus.cafe.ss
@@ -31,8 +31,8 @@ description:
   Input and output performed by the cafe can be changed by the
   console-input-port and console-output-port parameters.
   
-  If an error occurs during reading, evaluating, or printing an
-  expression, then the error is printed to the error-port and the
+  If an die occurs during reading, evaluating, or printing an
+  expression, then the die is printed to the error-port and the
   operations of the cafe resume as normal.|#
 #|FIXME:new-cafe
   Be specific about what the error-port is |#
@@ -112,7 +112,7 @@ description:
       [() (do-new-cafe default-cafe-eval)]
       [(p)
        (unless (procedure? p)
-         (error 'new-cafe "not a procedure" p))
+         (die 'new-cafe "not a procedure" p))
        (do-new-cafe p)]))
   )
 
diff --git a/scheme/ikarus.chars.ss b/scheme/ikarus.chars.ss
index ed54041..869a70c 100644
--- a/scheme/ikarus.chars.ss
+++ b/scheme/ikarus.chars.ss
@@ -26,26 +26,26 @@
   (define integer->char
     (lambda (n)
       (cond
-        [(not (fixnum? n)) (error 'integer->char "invalid argument" n)]
-        [($fx< n 0) (error 'integer->char "negative" n)]
+        [(not (fixnum? n)) (die 'integer->char "invalid argument" n)]
+        [($fx< n 0) (die 'integer->char "negative" n)]
         [($fx<= n #xD7FF) ($fixnum->char n)]
         [($fx< n #xE000)
-         (error 'integer->char "integer does not have a unicode representation" n)]
+         (die 'integer->char "integer does not have a unicode representation" n)]
         [($fx<= n #x10FFFF) ($fixnum->char n)]
-        [else (error 'integer->char 
+        [else (die 'integer->char 
                 "integer does not have a unicode representation" n)])))
   
   (define char->integer 
     (lambda (x) 
       (unless (char? x)
-        (error 'char->integer "not a character" x))
+        (die 'char->integer "not a character" x))
       ($char->fixnum x)))
 
   ;;; FIXME: this file is embarrasing
   (define char=?
     (let ()
       (define (err x)
-        (error 'char=? "not a character" x))
+        (die 'char=? "not a character" x))
       (case-lambda
         [(c1 c2)
          (if (char? c1)
@@ -82,7 +82,7 @@
   (define char<?
     (let ()
       (define (err x)
-        (error 'char<? "not a character" x))
+        (die 'char<? "not a character" x))
       (case-lambda
         [(c1 c2)
          (if (char? c1)
@@ -119,7 +119,7 @@
   (define char<=?
     (let ()
       (define (err x)
-        (error 'char<=? "not a character" x))
+        (die 'char<=? "not a character" x))
       (case-lambda
         [(c1 c2)
          (if (char? c1)
@@ -156,7 +156,7 @@
   (define char>?
     (let ()
       (define (err x)
-        (error 'char>? "not a character" x))
+        (die 'char>? "not a character" x))
       (case-lambda
         [(c1 c2)
          (if (char? c1)
@@ -193,7 +193,7 @@
   (define char>=?
     (let ()
       (define (err x)
-        (error 'char>=? "not a character" x))
+        (die 'char>=? "not a character" x))
       (case-lambda
         [(c1 c2)
          (if (char? c1)
diff --git a/scheme/ikarus.code-objects.ss b/scheme/ikarus.code-objects.ss
index 1e791c3..3266a5b 100644
--- a/scheme/ikarus.code-objects.ss
+++ b/scheme/ikarus.code-objects.ss
@@ -31,75 +31,75 @@
   (define make-code
     (lambda (code-size freevars)
       (unless (and (fixnum? code-size) ($fx>= code-size 0))
-        (error 'make-code "not a valid code size" code-size))
+        (die 'make-code "not a valid code size" code-size))
       (unless (and (fixnum? freevars) ($fx>= freevars 0))
-        (error 'make-code "not a valid number of free vars" freevars))
+        (die 'make-code "not a valid number of free vars" freevars))
       (foreign-call "ikrt_make_code" code-size freevars '#())))
 
   (define code-reloc-vector
     (lambda (x)
-      (unless (code? x) (error 'code-reloc-vector "not a code" x))
+      (unless (code? x) (die 'code-reloc-vector "not a code" x))
       ($code-reloc-vector x)))
 
   (define code-freevars
     (lambda (x)
-      (unless (code? x) (error 'code-closure-size "not a code" x))
+      (unless (code? x) (die 'code-closure-size "not a code" x))
       ($code-freevars x)))
 
   (define code-size
     (lambda (x)
-      (unless (code? x) (error 'code-size "not a code" x))
+      (unless (code? x) (die 'code-size "not a code" x))
       ($code-size x)))
 
   (define code-set!
     (lambda (x i v)
-      (unless (code? x) (error 'code-set! "not a code" x))
+      (unless (code? x) (die 'code-set! "not a code" x))
       (unless (and (fixnum? i)
                    ($fx>= i 0)
                    ($fx< i ($code-size x)))
-        (error 'code-set! "not a valid index" i))
+        (die 'code-set! "not a valid index" i))
       (unless (and (fixnum? v)
                    ($fx>= v 0)
                    ($fx< v 256))
-        (error 'code-set! "not a valid byte" v))
+        (die 'code-set! "not a valid byte" v))
       ($code-set! x i v)))
 
   (define code-ref
     (lambda (x i)
-      (unless (code? x) (error 'code-ref "not a code" x))
+      (unless (code? x) (die 'code-ref "not a code" x))
       (unless (and (fixnum? i)
                    ($fx>= i 0)
                    ($fx< i ($code-size x)))
-        (error 'code-ref "not a valid index" i))
+        (die 'code-ref "not a valid index" i))
       ($code-ref x i)))
 
   (define set-code-reloc-vector!
     (lambda (x v)
       (unless (code? x) 
-        (error 'set-code-reloc-vector! "not a code" x))
+        (die 'set-code-reloc-vector! "not a code" x))
       (unless (vector? v)
-        (error 'set-code-reloc-vector! "not a vector" v))
+        (die 'set-code-reloc-vector! "not a vector" v))
       (foreign-call "ikrt_set_code_reloc_vector" x v)))
 
 
   (define set-code-annotation!
     (lambda (x v)
       (unless (code? x) 
-        (error 'set-code-annotation! "not a code" x))
+        (die 'set-code-annotation! "not a code" x))
       (foreign-call "ikrt_set_code_annotation" x v)))
 
   (define code->thunk
     (lambda (x)
       (unless (code? x)
-        (error 'code->thunk "not a a code object" x))
+        (die 'code->thunk "not a a code object" x))
       (unless ($fxzero? ($code-freevars x))
-        (error 'code->thunk "has free variables" x))
+        (die 'code->thunk "has free variables" x))
       ($code->closure x)))
 
   (define (procedure-annotation x)
     (if (procedure? x) 
         ($code-annotation ($closure-code x))
-        (error 'procedure-annotation "not a procedure" x)))
+        (die 'procedure-annotation "not a procedure" x)))
 
   )
 
diff --git a/scheme/ikarus.codecs.ss b/scheme/ikarus.codecs.ss
index 296af45..bdec699 100644
--- a/scheme/ikarus.codecs.ss
+++ b/scheme/ikarus.codecs.ss
@@ -61,17 +61,17 @@
   (define (codec->fixnum x who)
     (cond
       [(assq x codec-alist) => cdr]
-      [else (error who "not a valid coded" x)]))
+      [else (die who "not a valid coded" x)]))
 
   (define (eol-style->fixnum x who)
     (cond
       [(assq x eol-style-alist) => cdr]
-      [else (error who "not a valid eol-style" x)]))
+      [else (die who "not a valid eol-style" x)]))
 
   (define (error-handling-mode->fixnum x who)
     (cond
       [(assq x error-handling-mode-alist) => cdr]
-      [else (error who "not a valid error-handling mode" x)]))
+      [else (die who "not a valid error-handling mode" x)]))
 
   (define make-transcoder
     (case-lambda
@@ -94,24 +94,24 @@
     (if (transcoder? x) 
         (let ([tag (fxlogand ($transcoder->data x) codec-mask)])
           (or (rev-lookup tag codec-alist)
-              (error who "transcoder has no codec" x)))
-        (error who "not a transcoder" x)))
+              (die who "transcoder has no codec" x)))
+        (die who "not a transcoder" x)))
 
   (define (transcoder-eol-style x) 
     (define who 'transcoder-eol-style)
     (if (transcoder? x) 
         (let ([tag (fxlogand ($transcoder->data x) eol-style-mask)])
           (or (rev-lookup tag eol-style-alist)
-              (error who "transcoder has no eol-style" x)))
-        (error who "not a transcoder" x)))
+              (die who "transcoder has no eol-style" x)))
+        (die who "not a transcoder" x)))
 
   (define (transcoder-error-handling-mode x) 
     (define who 'transcoder-error-handling-mode)
     (if (transcoder? x) 
         (let ([tag (fxlogand ($transcoder->data x) error-handling-mode-mask)])
           (or (rev-lookup tag error-handling-mode-alist)
-              (error who "transcoder has no error-handling mode" x)))
-        (error who "not a transcoder" x)))
+              (die who "transcoder has no error-handling mode" x)))
+        (die who "not a transcoder" x)))
 
   (define (buffer-mode? x)
     (and (memq x '(none line block)) #t))
@@ -133,7 +133,7 @@
       
   (define (file-options-spec ls)
     (unless (list? ls) 
-      (error 'file-options-spec "not a list" ls))
+      (die 'file-options-spec "not a list" ls))
     (let f ([ls ls] [n 0])
       (cond
         [(null? ls) (vector-ref file-options-vec n)]
diff --git a/scheme/ikarus.command-line.ss b/scheme/ikarus.command-line.ss
index e12ba93..907fe63 100644
--- a/scheme/ikarus.command-line.ss
+++ b/scheme/ikarus.command-line.ss
@@ -26,6 +26,6 @@
       (lambda (x)
         (if (and (list? x) (andmap string? x))
             x
-            (error 'command-list 
+            (die 'command-list 
               "invalid command-line-arguments ~s\n" x))))))
 
diff --git a/scheme/ikarus.conditions.ss b/scheme/ikarus.conditions.ss
index 89c8d7f..1ff7f69 100644
--- a/scheme/ikarus.conditions.ss
+++ b/scheme/ikarus.conditions.ss
@@ -148,7 +148,7 @@
       [(x) 
        (if (condition? x)
            x 
-           (error 'condition "not a condition type" x))]
+           (die 'condition "not a condition type" x))]
       [x*
        (let ([ls
               (let f ([x* x*])
@@ -158,7 +158,7 @@
                    (cons (car x*) (f (cdr x*)))]
                   [(compound-condition? (car x*)) 
                    (append (simple-conditions (car x*)) (f (cdr x*)))]
-                  [else (error 'condition "not a condition" (car x*))]))])
+                  [else (die 'condition "not a condition" (car x*))]))])
          (cond
            [(null? ls) (make-compound-condition '())]
            [(null? (cdr ls)) (car ls)]
@@ -168,13 +168,13 @@
     (cond
       [(compound-condition? x) (compound-condition-components x)]
       [(&condition? x) (list x)]
-      [else (error 'simple-conditions "not a condition" x)]))
+      [else (die 'simple-conditions "not a condition" x)]))
 
   (define (condition-predicate rtd) 
     (unless (rtd? rtd) 
-      (error 'condition-predicate "not a record type descriptor" rtd))
+      (die 'condition-predicate "not a record type descriptor" rtd))
     (unless (rtd-subtype? rtd (record-type-descriptor &condition))
-      (error 'condition-predicate "not a descendant of &condition" rtd))
+      (die 'condition-predicate "not a descendant of &condition" rtd))
     (let ([p? (record-predicate rtd)])
       (lambda (x) 
         (or (p? x) 
@@ -186,11 +186,11 @@
   
   (define (condition-accessor rtd proc) 
     (unless (rtd? rtd) 
-      (error 'condition-accessor "not a record type descriptor" rtd))
+      (die 'condition-accessor "not a record type descriptor" rtd))
     (unless (procedure? proc) 
-      (error 'condition-accessor "not a procedure" proc))
+      (die 'condition-accessor "not a procedure" proc))
     (unless (rtd-subtype? rtd (record-type-descriptor &condition))
-      (error 'condition-accessor "not a descendant of &condition" rtd))
+      (die 'condition-accessor "not a descendant of &condition" rtd))
     (let ([p? (record-predicate rtd)])
       (lambda (x) 
         (cond
@@ -203,9 +203,9 @@
                     (proc (car ls))
                     (f (cdr ls)))]
                [else
-                (error 'condition-accessor "not a condition of correct type" x rtd)]))]
+                (die 'condition-accessor "not a condition of correct type" x rtd)]))]
           [else 
-           (error 'condition-accessor "not a condition of correct type" x rtd)]))))
+           (die 'condition-accessor "not a condition of correct type" x rtd)]))))
 
   (define-syntax define-condition-type
     (lambda (x)
@@ -381,7 +381,7 @@
         [(x port)
          (if (output-port? port) 
              (print-condition x port)
-             (error 'print-condition "not an output port" port))])))
+             (die 'print-condition "not an output port" port))])))
 
   ;(let ([p 
   ;       (lambda (x p) 
diff --git a/scheme/ikarus.control.ss b/scheme/ikarus.control.ss
index 5d124cc..4dec194 100644
--- a/scheme/ikarus.control.ss
+++ b/scheme/ikarus.control.ss
@@ -32,7 +32,7 @@
     (lambda (f)
       (if (procedure? f)
           (primitive-call/cf f)
-          (error 'call/cf "not a procedure" f))))
+          (die 'call/cf "not a procedure" f))))
 
   (define primitive-call/cc
     (lambda (f)
@@ -92,7 +92,7 @@
   (define call/cc
     (lambda (f)
       (unless (procedure? f) 
-        (error 'call/cc "not a procedure" f))
+        (die 'call/cc "not a procedure" f))
       (primitive-call/cc
         (lambda (k)
           (let ([save winders])
@@ -106,18 +106,18 @@
   (define call-with-current-continuation
     (lambda (f)
       (unless (procedure? f) 
-        (error 'call-with-current-continuation
+        (die 'call-with-current-continuation
             "not a procedure" f))
       (call/cc f)))
 
   (define dynamic-wind
     (lambda (in body out)
       (unless (procedure? in)
-        (error 'dynamic-wind "not a procedure" in))
+        (die 'dynamic-wind "not a procedure" in))
       (unless (procedure? body)
-        (error 'dynamic-wind "not a procedure" body))
+        (die 'dynamic-wind "not a procedure" body))
       (unless (procedure? out)
-        (error 'dynamic-wind "not a procedure" out))
+        (die 'dynamic-wind "not a procedure" out))
       (in)
       (set! winders (cons (cons in out) winders))
       (call-with-values
diff --git a/scheme/ikarus.enumerations.ss b/scheme/ikarus.enumerations.ss
index dfd14c3..fa34961 100644
--- a/scheme/ikarus.enumerations.ss
+++ b/scheme/ikarus.enumerations.ss
@@ -33,20 +33,20 @@
   
   (define (make-enumeration ls) 
     (unless (and (list? ls) (for-all symbol? ls))
-      (error 'make-enumeration "~s is not a list of symbols" ls))
+      (die 'make-enumeration "~s is not a list of symbols" ls))
     (make-enum (gensym) ls ls))
   
   (define (enum-set-universe x)
     (unless (enum? x) 
-      (error 'enum-set-universe "~s is not an enumeration" x))
+      (die 'enum-set-universe "~s is not an enumeration" x))
     (enum-univ x))
   
   (define (enum-set-indexer x)
     (unless (enum? x) 
-      (error 'enum-set-indexer "~s is not an enumeration" x))
+      (die 'enum-set-indexer "~s is not an enumeration" x))
     (lambda (s)
       (unless (symbol? s) 
-        (error 'enum-set-indexer "~s is not a symbol" s))
+        (die 'enum-set-indexer "~s is not a symbol" s))
       (let f ([s s] [i 0] [ls (enum-univ x)])
         (cond
           [(pair? ls) 
@@ -57,15 +57,15 @@
   
   (define (enum-set-constructor x)
     (unless (enum? x) 
-      (error 'enum-set-constructor "~s is not an enumeration" x))
+      (die 'enum-set-constructor "~s is not an enumeration" x))
     (let ([idx (enum-set-indexer x)])
       (lambda (ls) 
         (unless (and (list? ls) (for-all symbol? ls))
-          (error 'enum-set-constructor "~s is not a list of symbols" ls))
+          (die 'enum-set-constructor "~s is not a list of symbols" ls))
         (for-each 
           (lambda (s) 
             (unless (memq s (enum-univ x))
-              (error 'enum-set-constructor "~s is not in the universe of ~s" s x)))
+              (die 'enum-set-constructor "~s is not in the universe of ~s" s x)))
           ls)
         (make-enum (enum-g x) (enum-univ x) 
           (map car
@@ -75,7 +75,7 @@
     
   (define (enum-set->list x)
     (unless (enum? x) 
-      (error 'enum-set->list "~s is not an enumeration" x))
+      (die 'enum-set->list "~s is not an enumeration" x))
     (map values (enum-values x)))
   
   (define (enum-set-member? s x) 
@@ -84,8 +84,8 @@
             #t
             (if (symbol? s) 
                 #f 
-                (error 'enum-set-member? "not a symbol" s)))
-        (error 'enum-set-member? "not an enumeration" x)))
+                (die 'enum-set-member? "not a symbol" s)))
+        (die 'enum-set-member? "not an enumeration" x)))
   
   (define (enum-set-subset? x1 x2) 
     (define (subset? s1 s2) 
@@ -97,8 +97,8 @@
             (and (subset? (enum-values x1) (enum-values x2))
                  (or (eq? (enum-g x1) (enum-g x2))
                      (subset? (enum-univ x1) (enum-univ x2))))
-            (error 'enum-set-subset? "not an enumeration" x2))
-        (error 'enum-set-subset? "not an enumeration" x1)))
+            (die 'enum-set-subset? "not an enumeration" x2))
+        (die 'enum-set-subset? "not an enumeration" x1)))
   
   (define (enum-set=? x1 x2) 
     (define (subset? s1 s2) 
@@ -112,8 +112,8 @@
                  (or (eq? (enum-g x1) (enum-g x2))
                      (and (subset? (enum-univ x1) (enum-univ x2))
                           (subset? (enum-univ x2) (enum-univ x1)))))
-            (error 'enum-set=? "not an enumeration" x2))
-        (error 'enum-set=? "not an enumeration" x1)))
+            (die 'enum-set=? "not an enumeration" x2))
+        (die 'enum-set=? "not an enumeration" x1)))
   
   (define (enum-set-op x1 x2 who combine)
     (if (enum? x1) 
@@ -121,10 +121,10 @@
             (let ([g (enum-g x1)] [u (enum-univ x1)])
               (if (eq? g (enum-g x2))
                   (make-enum g u (combine u (enum-values x1) (enum-values x2)))
-                  (error who 
+                  (die who 
                     "enum sets have different enumeration types" x1 x2)))
-            (error who "not an enumeration" x2))
-        (error who "not an enumeration" x1)))
+            (die who "not an enumeration" x2))
+        (die who "not an enumeration" x1)))
   
   (define (enum-set-union x1 x2)
     (define (union u s1 s2) 
@@ -183,7 +183,7 @@
     (if (enum? x) 
         (let ([g (enum-g x)] [u (enum-univ x)])
            (make-enum g u (complement u (enum-values x))))
-        (error 'enum-set-complement "not an enumeration" x)))
+        (die 'enum-set-complement "not an enumeration" x)))
   
   (define (enum-set-projection x1 x2)
     (define (combine u s) 
@@ -202,8 +202,8 @@
                     (if (null? s) 
                         (make-enum g u '())
                         (make-enum g u (combine u s))))))
-            (error 'enum-set-projection "not an enumeration" x2))
-        (error 'enum-set-projection "not an enumeration" x1)))
+            (die 'enum-set-projection "not an enumeration" x2))
+        (die 'enum-set-projection "not an enumeration" x1)))
 )
 
 #!eof
diff --git a/scheme/ikarus.exceptions.ss b/scheme/ikarus.exceptions.ss
index 3f6dcd9..3bb7e7f 100644
--- a/scheme/ikarus.exceptions.ss
+++ b/scheme/ikarus.exceptions.ss
@@ -16,14 +16,14 @@
 
 (library (ikarus exceptions)
   (export with-exception-handler raise raise-continuable 
-    error assertion-violation)
+    error assertion-violation die)
   (import 
     (only (rnrs) condition make-non-continuable-violation
           make-message-condition make-error make-who-condition
           make-irritants-condition make-assertion-violation)
     (except (ikarus)
       with-exception-handler raise raise-continuable 
-      error assertion-violation))
+      error assertion-violation die))
 
   (define handlers
     (make-parameter
@@ -35,10 +35,10 @@
   
   (define (with-exception-handler handler proc2)
     (unless (procedure? handler)
-      (error 'with-exception-handler
+      (assertion-violation 'with-exception-handler
         "handler is not a procedure" handler))
     (unless (procedure? proc2)
-      (error 'with-exception-handler "not a procedure" proc2))
+      (assertion-violation 'with-exception-handler "not a procedure" proc2))
     (parameterize ([handlers (cons handler (handlers))])
       (proc2)))
   
@@ -60,7 +60,7 @@
 
   (define (error who msg . irritants) 
     (unless (string? msg) 
-      (error 'error "message is not a string" msg))
+      (assertion-violation 'error "message is not a string" msg))
     (raise
        (condition
          (make-error)
@@ -82,5 +82,8 @@
              (condition)
              (make-irritants-condition irritants)))))
 
+  (define die assertion-violation)
+  
+
 )
 
diff --git a/scheme/ikarus.fasl.ss b/scheme/ikarus.fasl.ss
index d31a637..a3c5f61 100644
--- a/scheme/ikarus.fasl.ss
+++ b/scheme/ikarus.fasl.ss
@@ -63,12 +63,12 @@
   (define who 'fasl-read)
   (define (assert-eq? x y)
     (unless (eq? x y)
-      (error who 
+      (die who 
         (format "Expected ~s, got ~s\n" y x))))
   (define (char->int x)
     (if (char? x)
         (char->integer x)
-        (error who "unexpected eof inside a fasl object")))
+        (die who "unexpected eof inside a fasl object")))
   (define (read-fixnum p)
     (let ([c0 (char->int (read-char p))]
           [c1 (char->int (read-char p))]
@@ -115,7 +115,7 @@
       (cond
         [(fx< m (vector-length marks))
          (when (vector-ref marks m)
-           (error 'fasl-read "mark set twice" m))
+           (die 'fasl-read "mark set twice" m))
          (vector-set! marks m obj)]
         [else
          (let ([n (vector-length marks)])
@@ -158,7 +158,7 @@
           [(#\<) 
            (let ([cm (read-int p)])
              (unless (fx< cm (vector-length marks))
-               (error who "invalid mark" m))
+               (die who "invalid mark" m))
              (let ([code (vector-ref marks cm)])
                (let ([proc ($code->closure code)])
                  (when m (put-mark m proc))
@@ -168,10 +168,10 @@
              (assert-eq? (read-char p) #\x)
              (let ([code (read-code cm m)])
                (if m (vector-ref marks m) ($code->closure code))))]
-          [else (error who "invalid code header" c)])))
+          [else (die who "invalid code header" c)])))
     (define (read/mark m)
       (define (nom)
-        (when m (error who "unhandled mark")))
+        (when m (die who "unhandled mark")))
       (let ([h (read-char p)])
         (case h
           [(#\I) 
@@ -253,17 +253,17 @@
              (cond
                [(char? c) c]
                [else
-                (error who "invalid eof inside a fasl object")]))]
+                (die who "invalid eof inside a fasl object")]))]
           [(#\>)
            (let ([m (read-int p)])
              (read/mark m))]
           [(#\<)
            (let ([m (read-int p)])
              (unless (fx< m (vector-length marks))
-               (error who "invalid mark" m))
+               (die who "invalid mark" m))
              (vector-ref marks m))]
           [else
-           (error who "Unexpected char as a fasl object header" h)])))
+           (die who "Unexpected char as a fasl object header" h)])))
     (read))
   (define $fasl-read
     (lambda (p)
@@ -279,7 +279,7 @@
       [(p) 
        (if (input-port? p) 
            ($fasl-read p)
-           (error 'fasl-read "not an input port" p))]))
+           (die 'fasl-read "not an input port" p))]))
 
   )
 
diff --git a/scheme/ikarus.fasl.write.ss b/scheme/ikarus.fasl.write.ss
index 92ee053..c6e8933 100644
--- a/scheme/ikarus.fasl.write.ss
+++ b/scheme/ikarus.fasl.write.ss
@@ -40,14 +40,14 @@
   
   (define write-fixnum 
     (lambda (x p)
-      (unless (fixnum? x) (error 'write-fixnum "not a fixnum" x))
+      (unless (fixnum? x) (die 'write-fixnum "not a fixnum" x))
       (write-byte (fxsll (fxlogand x #x3F) 2) p)
       (write-byte (fxlogand (fxsra x 6) #xFF) p)
       (write-byte (fxlogand (fxsra x 14) #xFF) p)
       (write-byte (fxlogand (fxsra x 22) #xFF) p)))
   (define write-int 
     (lambda (x p)
-      (unless (fixnum? x) (error 'write-int "not a fixnum" x))
+      (unless (fixnum? x) (die 'write-int "not a fixnum" x))
       (write-byte (fxlogand x #xFF) p)
       (write-byte (fxlogand (fxsra x 8) #xFF) p)
       (write-byte (fxlogand (fxsra x 16) #xFF) p)
@@ -72,7 +72,7 @@
          (put-tag (if x #\T #\F) p)]
         [(eof-object? x) (put-tag #\E p)]
         [(eq? x (void)) (put-tag #\U p)]
-        [else (error 'fasl-write "not a fasl-writable immediate" x)])))
+        [else (die 'fasl-write "not a fasl-writable immediate" x)])))
   
   (define (ascii-string? s)
     (let f ([s s] [i 0] [n (string-length s)])
@@ -222,7 +222,7 @@
                (write-byte ($bignum-byte-ref x i) p)
                (f (fxadd1 i)))))
          m]
-        [else (error 'fasl-write "not fasl-writable" x)])))
+        [else (die 'fasl-write "not fasl-writable" x)])))
   (define (write-bytevector x i j p)
     (unless ($fx= i j)
       (write-byte ($bytevector-u8-ref x i) p)
@@ -234,7 +234,7 @@
         [(hashtable-ref h x #f) =>
          (lambda (mark)
            (unless (fixnum? mark)
-             (error 'fasl-write "BUG: invalid mark" mark))
+             (die 'fasl-write "BUG: invalid mark" mark))
            (cond
              [(fx= mark 0) ; singly referenced
               (do-write x p h m)]
@@ -247,7 +247,7 @@
               (put-tag #\< p)
               (write-int (fx- 0 mark) p)
               m]))]
-        [else (error 'fasl-write "BUG: not in hash table" x)]))) 
+        [else (die 'fasl-write "BUG: not in hash table" x)]))) 
   (define make-graph
     (lambda (x h)
       (unless (immediate? x)
@@ -275,7 +275,7 @@
               (make-graph (code-reloc-vector x) h)]
              [(struct? x)
               (when (eq? x (base-rtd))
-                (error 'fasl-write "base-rtd is not writable"))
+                (die 'fasl-write "base-rtd is not writable"))
               (let ([rtd (struct-type-descriptor x)])
                 (cond
                   [(eq? rtd (base-rtd))
@@ -294,7 +294,7 @@
              [(procedure? x)
               (let ([code ($closure-code x)])
                 (unless (fxzero? (code-freevars code))
-                  (error 'fasl-write
+                  (die 'fasl-write
                     "Cannot write a non-thunk procedure; \
                      the one given has free vars"
                     (code-freevars code)))
@@ -305,7 +305,7 @@
              [(ratnum? x) 
               (make-graph (numerator x) h)
               (make-graph (denominator x) h)]
-             [else (error 'fasl-write "not fasl-writable" x)])]))))
+             [else (die 'fasl-write "not fasl-writable" x)])]))))
   (define fasl-write-to-port
     (lambda (x port)
       (let ([h (make-eq-hashtable)])
@@ -322,5 +322,5 @@
     (case-lambda 
       [(x port)
        (unless (and (output-port? port) (binary-port? port))
-         (error 'fasl-write "not an output port" port))
+         (die 'fasl-write "not an output port" port))
        (fasl-write-to-port x port)])))
diff --git a/scheme/ikarus.fixnums.ss b/scheme/ikarus.fixnums.ss
index c2c9c0d..8206d7c 100644
--- a/scheme/ikarus.fixnums.ss
+++ b/scheme/ikarus.fixnums.ss
@@ -50,39 +50,39 @@
       (cond
         [(eq? x 0) #t]
         [(fixnum? x) #f]
-        [else (error 'fxzero? "not a fixnum" x)])))
+        [else (die 'fxzero? "not a fixnum" x)])))
   
   (define fxadd1
     (lambda (n)
       (if (fixnum? n)
           ($fxadd1 n)
-          (error 'fxadd1 "not a fixnum" n))))
+          (die 'fxadd1 "not a fixnum" n))))
   
   (define fxsub1 
     (lambda (n) 
       (if (fixnum? n)
           ($fxsub1 n)
-          (error 'fxsub1 "not a fixnum" n))))
+          (die 'fxsub1 "not a fixnum" n))))
 
   (define fxlognot 
     (lambda (x)
       (unless (fixnum? x) 
-        (error 'fxlognot "not a fixnum" x))
+        (die 'fxlognot "not a fixnum" x))
       ($fxlognot x)))
 
   (define fxnot 
     (lambda (x)
       (unless (fixnum? x) 
-        (error 'fxnot "not a fixnum" x))
+        (die 'fxnot "not a fixnum" x))
       ($fxlognot x)))
   
   (define error@fx+
     (lambda (x y) 
       (if (fixnum? x) 
           (if (fixnum? y) 
-              (error 'fx+ "overflow when adding numbers" x y)
-              (error 'fx+ "not a fixnum" y))
-          (error 'fx+ "not a fixnum" x))))
+              (die 'fx+ "overflow when adding numbers" x y)
+              (die 'fx+ "not a fixnum" y))
+          (die 'fx+ "not a fixnum" x))))
 
   (define fx+ 
     (lambda (x y) 
@@ -91,17 +91,17 @@
   (define fx-
     (lambda (x y) 
       (unless (fixnum? x)
-        (error 'fx- "not a fixnum" x))
+        (die 'fx- "not a fixnum" x))
       (unless (fixnum? y)
-        (error 'fx- "not a fixnum" y))
+        (die 'fx- "not a fixnum" y))
       ($fx- x y)))
 
   (define fx*
     (lambda (x y) 
       (unless (fixnum? x)
-        (error 'fx* "not a fixnum" x))
+        (die 'fx* "not a fixnum" x))
       (unless (fixnum? y)
-        (error 'fx* "not a fixnum" y))
+        (die 'fx* "not a fixnum" y))
       ($fx* x y)))
   
 
@@ -110,7 +110,7 @@
       (if (pair? ls) 
           (if (fixnum? ($car ls)) 
               (false-loop who ($cdr ls))
-              (error who "not a fixnum" ($car ls)))
+              (die who "not a fixnum" ($car ls)))
           #f)))
 
   (define-syntax fxcmp 
@@ -119,9 +119,9 @@
        (case-lambda
          [(x y) 
           (unless (fixnum? x)
-            (error 'who "not a fixnum" x))
+            (die 'who "not a fixnum" x))
           (unless (fixnum? y)
-            (error 'who "not a fixnum" y))
+            (die 'who "not a fixnum" y))
           ($op x y)]
          [(x y . ls)
           (if (fixnum? x)
@@ -134,13 +134,13 @@
                                   (if ($op x y) 
                                       (f y ls)
                                       (false-loop 'who ls))
-                                  (error 'who "not a fixnum" y)))
+                                  (die 'who "not a fixnum" y)))
                             #t))
                       (false-loop 'who ls))
-                  (error 'who "not a fixnum" y))
-              (error 'who "not a fixnum" x))]
+                  (die 'who "not a fixnum" y))
+              (die 'who "not a fixnum" x))]
          [(x) 
-          (if (fixnum? x) #t (error 'who "not a fixnum" x))])]))
+          (if (fixnum? x) #t (die 'who "not a fixnum" x))])]))
   
   (define fx=   (fxcmp fx= $fx=))
   (define fx<   (fxcmp fx< $fx<))
@@ -157,32 +157,32 @@
   (define fxquotient
     (lambda (x y) 
       (unless (fixnum? x)
-        (error 'fxquotient "not a fixnum" x))
+        (die 'fxquotient "not a fixnum" x))
       (unless (fixnum? y)
-        (error 'fxquotient "not a fixnum" y))
+        (die 'fxquotient "not a fixnum" y))
       (when ($fxzero? y)
-        (error 'fxquotient "zero dividend" y))
+        (die 'fxquotient "zero dividend" y))
       ($fxquotient x y))) 
   
   (define fxremainder
     (lambda (x y) 
       (unless (fixnum? x)
-        (error 'fxremainder "not a fixnum" x))
+        (die 'fxremainder "not a fixnum" x))
       (unless (fixnum? y)
-        (error 'fxremainder "not a fixnum" y))
+        (die 'fxremainder "not a fixnum" y))
       (when ($fxzero? y)
-        (error 'fxremainder "zero dividend" y))
+        (die 'fxremainder "zero dividend" y))
       (let ([q ($fxquotient x y)])
         ($fx- x ($fx* q y)))))
    
   (define fxmodulo
     (lambda (x y) 
       (unless (fixnum? x)
-        (error 'fxmodulo "not a fixnum" x))
+        (die 'fxmodulo "not a fixnum" x))
       (unless (fixnum? y)
-        (error 'fxmodulo "not a fixnum" y))
+        (die 'fxmodulo "not a fixnum" y))
       (when ($fxzero? y)
-        (error 'fxmodulo "zero dividend" y))
+        (die 'fxmodulo "zero dividend" y))
       ($fxmodulo x y)))
 
   (define-syntax fxbitop
@@ -193,8 +193,8 @@
           (if (fixnum? x) 
               (if (fixnum? y) 
                   ($op x y)
-                  (error 'who "not a fixnum" y))
-              (error 'who "not a fixnum" x))]
+                  (die 'who "not a fixnum" y))
+              (die 'who "not a fixnum" x))]
          [(x y . ls) 
           (if (fixnum? x)
               (if (fixnum? y) 
@@ -204,11 +204,11 @@
                        (let ([b ($car ls)])
                          (if (fixnum? b) 
                              (f ($op a b) ($cdr ls))
-                             (error 'who "not a fixnum" b)))]
+                             (die 'who "not a fixnum" b)))]
                       [else a]))
-                  (error 'who "not a fixnum" y))
-              (error 'who "not a fixnum" x))]
-         [(x) (if (fixnum? x) x (error 'who "not a fixnum" x))]
+                  (die 'who "not a fixnum" y))
+              (die 'who "not a fixnum" x))]
+         [(x) (if (fixnum? x) x (die 'who "not a fixnum" x))]
          [()   identity])]))
 
   (define fxlogor (fxbitop fxlogor $fxlogor 0))
@@ -225,58 +225,58 @@
                 ($fxlogor 
                   ($fxlogand x y) 
                   ($fxlogand ($fxlognot x) z))
-                (error 'fxif "not a fixnum" z))
-            (error 'fxif "not a fixnum" y))
-        (error 'fxif "not a fixnum" x)))
+                (die 'fxif "not a fixnum" z))
+            (die 'fxif "not a fixnum" y))
+        (die 'fxif "not a fixnum" x)))
 
   (define fxsra
     (lambda (x y) 
       (unless (fixnum? x)
-        (error 'fxsra "not a fixnum" x))
+        (die 'fxsra "not a fixnum" x))
       (unless (fixnum? y)
-        (error 'fxsra "not a fixnum" y))
+        (die 'fxsra "not a fixnum" y))
       (unless ($fx>= y 0)
-        (error 'fxsra "negative shift not allowed" y))
+        (die 'fxsra "negative shift not allowed" y))
       ($fxsra x y)))
    
 
   (define fxarithmetic-shift-right
     (lambda (x y) 
       (unless (fixnum? x)
-        (error 'fxarithmetic-shift-right "not a fixnum" x))
+        (die 'fxarithmetic-shift-right "not a fixnum" x))
       (unless (fixnum? y)
-        (error 'fxarithmetic-shift-right "not a fixnum" y))
+        (die 'fxarithmetic-shift-right "not a fixnum" y))
       (unless ($fx>= y 0)
-        (error 'fxarithmetic-shift-right "negative shift not allowed" y))
+        (die 'fxarithmetic-shift-right "negative shift not allowed" y))
       ($fxsra x y)))
 
   (define fxsll
     (lambda (x y) 
       (unless (fixnum? x)
-        (error 'fxsll "not a fixnum" x))
+        (die 'fxsll "not a fixnum" x))
       (unless (fixnum? y)
-        (error 'fxsll "not a fixnum" y))
+        (die 'fxsll "not a fixnum" y))
       (unless ($fx>= y 0)
-        (error 'fxsll "negative shift not allowed" y))
+        (die 'fxsll "negative shift not allowed" y))
       ($fxsll x y))) 
 
 
   (define fxarithmetic-shift-left
     (lambda (x y) 
       (unless (fixnum? x)
-        (error 'fxarithmetic-shift-left "not a fixnum" x))
+        (die 'fxarithmetic-shift-left "not a fixnum" x))
       (unless (fixnum? y)
-        (error 'fxarithmetic-shift-left "not a fixnum" y))
+        (die 'fxarithmetic-shift-left "not a fixnum" y))
       (unless ($fx>= y 0)
-        (error 'fxarithmetic-shift-left "negative shift not allowed" y))
+        (die 'fxarithmetic-shift-left "negative shift not allowed" y))
       ($fxsll x y)))
 
   (define fxarithmetic-shift
     (lambda (x y) 
       (unless (fixnum? x)
-        (error 'fxarithmetic-shift "not a fixnum" x))
+        (die 'fxarithmetic-shift "not a fixnum" x))
       (unless (fixnum? y)
-        (error 'fxarithmetic-shift "not a fixnum" y))
+        (die 'fxarithmetic-shift "not a fixnum" y))
       (if ($fx>= y 0)
           ($fxsll x y)
           (if ($fx< x -100) ;;; arbitrary number < (fixnum-width)
@@ -286,22 +286,22 @@
   (define (fxpositive? x)
     (if (fixnum? x) 
         ($fx> x 0)
-        (error 'fxpositive? "not a fixnum" x)))
+        (die 'fxpositive? "not a fixnum" x)))
 
   (define (fxnegative? x)
     (if (fixnum? x) 
         ($fx< x 0)
-        (error 'fxnegative? "not a fixnum" x)))
+        (die 'fxnegative? "not a fixnum" x)))
   
   (define (fxeven? x)
     (if (fixnum? x) 
         ($fxzero? ($fxlogand x 1))
-        (error 'fxeven? "not a fixnum" x)))
+        (die 'fxeven? "not a fixnum" x)))
 
   (define (fxodd? x)
     (if (fixnum? x) 
         (not ($fxzero? ($fxlogand x 1)))
-        (error 'fxodd? "not a fixnum" x)))
+        (die 'fxodd? "not a fixnum" x)))
 
   (define fxmin
     (case-lambda 
@@ -309,8 +309,8 @@
        (if (fixnum? x) 
            (if (fixnum? y) 
                (if ($fx< x y) x y)
-               (error 'fxmin "not a fixnum" y))
-           (error 'fxmin "not a fixnum" x))]
+               (die 'fxmin "not a fixnum" y))
+           (die 'fxmin "not a fixnum" x))]
       [(x y z . ls)
        (fxmin (fxmin x y) 
          (if (fixnum? z) 
@@ -322,9 +322,9 @@
                          (if ($fx< a z) 
                              (f a ($cdr ls))
                              (f z ($cdr ls)))
-                         (error 'fxmin "not a fixnum" a)))))
-             (error 'fxmin "not a fixnum" z)))]
-      [(x) (if (fixnum? x) x (error 'fxmin "not a fixnum" x))]))
+                         (die 'fxmin "not a fixnum" a)))))
+             (die 'fxmin "not a fixnum" z)))]
+      [(x) (if (fixnum? x) x (die 'fxmin "not a fixnum" x))]))
 
   (define fxmax
     (case-lambda 
@@ -332,8 +332,8 @@
        (if (fixnum? x) 
            (if (fixnum? y) 
                (if ($fx> x y) x y)
-               (error 'fxmax "not a fixnum" y))
-           (error 'fxmax "not a fixnum" x))]
+               (die 'fxmax "not a fixnum" y))
+           (die 'fxmax "not a fixnum" x))]
       [(x y z . ls)
        (fxmax (fxmax x y) 
          (if (fixnum? z) 
@@ -345,9 +345,9 @@
                          (if ($fx> a z)
                              (f a ($cdr ls))
                              (f z ($cdr ls)))
-                         (error 'fxmax "not a fixnum" a)))))
-             (error 'fxmax "not a fixnum" z)))]
-      [(x) (if (fixnum? x) x (error 'fxmax "not a fixnum" x))]))
+                         (die 'fxmax "not a fixnum" a)))))
+             (die 'fxmax "not a fixnum" z)))]
+      [(x) (if (fixnum? x) x (die 'fxmax "not a fixnum" x))]))
 
   (define (fx*/carry fx1 fx2 fx3)
     (let ([s0 ($fx+ ($fx* fx1 fx2) fx3)])
@@ -404,16 +404,16 @@
     (define fixnum->string
       (case-lambda
         [(x) 
-         (unless (fixnum? x) (error 'fixnum->string "not a fixnum" x))
+         (unless (fixnum? x) (die 'fixnum->string "not a fixnum" x))
          ($fixnum->string x 10)]
         [(x r) 
-         (unless (fixnum? x) (error 'fixnum->string "not a fixnum" x))
+         (unless (fixnum? x) (die 'fixnum->string "not a fixnum" x))
          (case r
            [(2)  ($fixnum->string x 2)]
            [(8)  ($fixnum->string x 8)]
            [(10) ($fixnum->string x 10)]
            [(16) ($fixnum->string x 16)]
-           [else (error 'fixnum->string "invalid radix" r)])])))
+           [else (die 'fixnum->string "invalid radix" r)])])))
 
 
   )
@@ -454,28 +454,28 @@
     (if (fixnum? x) 
         (if (fixnum? y) 
             (if ($fx= y 0) 
-                (error 'fxdiv-and-mod "division by 0")
+                (die 'fxdiv-and-mod "division by 0")
                 ($fxdiv-and-mod x y))
-            (error 'fxdiv-and-mod "not a fixnum" y))
-        (error 'fxdiv-and-mod "not a fixnum" x)))
+            (die 'fxdiv-and-mod "not a fixnum" y))
+        (die 'fxdiv-and-mod "not a fixnum" x)))
 
   (define (fxdiv x y)
     (if (fixnum? x) 
         (if (fixnum? y) 
             (if ($fx= y 0) 
-                (error 'fxdiv "division by 0")
+                (die 'fxdiv "division by 0")
                 ($fxdiv x y))
-            (error 'fxdiv "not a fixnum" y))
-        (error 'fxdiv "not a fixnum" x)))
+            (die 'fxdiv "not a fixnum" y))
+        (die 'fxdiv "not a fixnum" x)))
 
   (define (fxmod x y)
     (if (fixnum? x) 
         (if (fixnum? y) 
             (if ($fx= y 0) 
-                (error 'fxmod "modision by 0")
+                (die 'fxmod "modision by 0")
                 ($fxmod x y))
-            (error 'fxmod "not a fixnum" y))
-        (error 'fxmod "not a fixnum" x)))
+            (die 'fxmod "not a fixnum" y))
+        (die 'fxmod "not a fixnum" x)))
 
   (define ($fxdiv0-and-mod0 n m)
     (let ([d0 (quotient n m)])
@@ -526,43 +526,43 @@
     (if (fixnum? x)
         (if (fixnum? y)
             (if ($fx= y 0)
-                (error 'fxdiv0-and-mod0 "division by 0")
+                (die 'fxdiv0-and-mod0 "division by 0")
                 (let-values ([(d m) ($fxdiv0-and-mod0 x y)])
                   (if (and (fixnum? d) (fixnum? m))
                       (values d m)
-                      (error 'fxdiv0-and-mod0 
+                      (die 'fxdiv0-and-mod0 
                         "results not representable as fixnums"
                         x y))))
-            (error 'fxdiv0-and-mod0 "not a fixnum" y))
-        (error 'fxdiv0-and-mod0 "not a fixnum" x)))
+            (die 'fxdiv0-and-mod0 "not a fixnum" y))
+        (die 'fxdiv0-and-mod0 "not a fixnum" x)))
 
   (define (fxdiv0 x y)
     (if (fixnum? x)
         (if (fixnum? y)
             (if ($fx= y 0)
-                (error 'fxdiv0 "division by 0")
+                (die 'fxdiv0 "division by 0")
                 (let ([d ($fxdiv0 x y)])
                   (if (fixnum? d)
                       d
-                      (error 'fxdiv0 
+                      (die 'fxdiv0 
                         "result not representable as fixnum"
                         x y))))
-            (error 'fxdiv0 "not a fixnum" y))
-        (error 'fxdiv0 "not a fixnum" x)))
+            (die 'fxdiv0 "not a fixnum" y))
+        (die 'fxdiv0 "not a fixnum" x)))
 
   (define (fxmod0 x y)
     (if (fixnum? x)
         (if (fixnum? y)
             (if ($fx= y 0)
-                (error 'fxmod0 "division by 0")
+                (die 'fxmod0 "division by 0")
                 (let ([d ($fxmod0 x y)])
                   (if (fixnum? d)
                       d
-                      (error 'fxmod0 
+                      (die 'fxmod0 
                         "result not representable as fixnum"
                         x y))))
-            (error 'fxmod0 "not a fixnum" y))
-        (error 'fxmod0 "not a fixnum" x)))
+            (die 'fxmod0 "not a fixnum" y))
+        (die 'fxmod0 "not a fixnum" x)))
   )
 
 
diff --git a/scheme/ikarus.handlers.ss b/scheme/ikarus.handlers.ss
index df37728..276c804 100644
--- a/scheme/ikarus.handlers.ss
+++ b/scheme/ikarus.handlers.ss
@@ -25,7 +25,7 @@
          [(v) (set! x v)])]
       [(x guard)
        (unless (procedure? guard)
-         (error 'make-parameter "not a procedure" guard))
+         (die 'make-parameter "not a procedure" guard))
        (set! x (guard x))
        (case-lambda
          [() x]
@@ -55,19 +55,19 @@
       (lambda (x)
         (if (procedure? x)
             x
-            (error 'interrupt-handler "not a procedure" x)))))
+            (die 'interrupt-handler "not a procedure" x)))))
 
   (define $apply-nonprocedure-error-handler
     (lambda (x)
-      (error 'apply "not a procedure" x)))
+      (die 'apply "not a procedure" x)))
   
   (define $incorrect-args-error-handler
     (lambda (p n)
-      (error 'apply "incorrect number of arguments" n p)))
+      (die 'apply "incorrect number of arguments" n p)))
   
   (define $multiple-values-error
     (lambda args
-      (error 'apply 
+      (die 'apply 
              "incorrect number of values returned to single value context" 
              args)))
   
@@ -84,47 +84,47 @@
       (cond
         [(symbol? x)
          (if (symbol-bound? x)
-             (error 'top-level-value-error "BUG: should not happen" x)
-             (error #f "unbound" (string->symbol (symbol->string x))))]
+             (die 'top-level-value-error "BUG: should not happen" x)
+             (die #f "unbound" (string->symbol (symbol->string x))))]
         [else
-         (error 'top-level-value "not a symbol" x)])))
+         (die 'top-level-value "not a symbol" x)])))
   
   (define car-error
     (lambda (x)
-      (error 'car "not a pair" x)))
+      (die 'car "not a pair" x)))
   
   (define cdr-error
     (lambda (x)
-      (error 'cdr "not a pair" x)))
+      (die 'cdr "not a pair" x)))
   
   (define fxadd1-error
     (lambda (x)
       (if (fixnum? x)
-          (error 'fxadd1 "overflow")
-          (error 'fxadd1 "not a fixnum" x))))
+          (die 'fxadd1 "overflow")
+          (die 'fxadd1 "not a fixnum" x))))
   
   (define fxsub1-error
     (lambda (x)
       (if (fixnum? x)
-          (error 'fxsub1 "underflow")
-          (error 'fxsub1 "not a fixnum" x))))
+          (die 'fxsub1 "underflow")
+          (die 'fxsub1 "not a fixnum" x))))
   
   (define cadr-error
     (lambda (x)
-      (error 'cadr "invalid list structure" x)))
+      (die 'cadr "invalid list structure" x)))
   
   (define fx+-type-error
     (lambda (x)
-      (error 'fx+ "not a fixnum" x)))
+      (die 'fx+ "not a fixnum" x)))
   
   (define fx+-types-error
     (lambda (x y)
-      (error 'fx+ "not a fixnum"
+      (die 'fx+ "not a fixnum"
              (if (fixnum? x) y x))))
   
   (define fx+-overflow-error
     (lambda (x y)
-      (error 'fx+ "overflow")))
+      (die 'fx+ "overflow")))
   
   (define $do-event
     (lambda ()
diff --git a/scheme/ikarus.hash-tables.ss b/scheme/ikarus.hash-tables.ss
index 67aecfd..a1efe14 100644
--- a/scheme/ikarus.hash-tables.ss
+++ b/scheme/ikarus.hash-tables.ss
@@ -311,28 +311,28 @@
        (if (and (or (fixnum? k) (bignum? k))
                 (>= k 0))
            (make-eq-hashtable)
-           (error 'make-eq-hashtable
+           (die 'make-eq-hashtable
              "invalid initial capacity" k))]))
 
   (define hashtable-ref
     (lambda (h x v)
       (if (hasht? h)
           (get-hash h x v)
-          (error 'hashtable-ref "not a hash table" h))))
+          (die 'hashtable-ref "not a hash table" h))))
 
   (define hashtable-contains?
     (lambda (h x)
       (if (hasht? h)
           (in-hash? h x)
-          (error 'hashtable-contains? "not a hash table" h))))
+          (die 'hashtable-contains? "not a hash table" h))))
 
   (define hashtable-set!
     (lambda (h x v)
       (if (hasht? h)
           (if (hasht-mutable? h) 
               (put-hash! h x v)
-              (error 'hashtable-set! "hashtable is immutable" h))
-          (error 'hashtable-set! "not a hash table" h))))
+              (die 'hashtable-set! "hashtable is immutable" h))
+          (die 'hashtable-set! "not a hash table" h))))
 
   (define hashtable-update!
     (lambda (h x proc default)
@@ -340,15 +340,15 @@
           (if (hasht-mutable? h)
               (if (procedure? proc)
                   (update-hash! h x proc default)
-                  (error 'hashtable-update! "not a procedure" proc))
-              (error 'hashtable-update! "hashtable is immutable" h))
-          (error 'hashtable-update! "not a hash table" h))))
+                  (die 'hashtable-update! "not a procedure" proc))
+              (die 'hashtable-update! "hashtable is immutable" h))
+          (die 'hashtable-update! "not a hash table" h))))
 
   (define hashtable-size
     (lambda (h)
       (if (hasht? h) 
           (hasht-count h)
-          (error 'hashtable-size "not a hash table" h))))
+          (die 'hashtable-size "not a hash table" h))))
 
   (define hashtable-delete!
     (lambda (h x) 
@@ -357,30 +357,30 @@
       (if (hasht? h)
           (if (hasht-mutable? h)
               (del-hash h x)
-              (error 'hashtable-delete! "hashtable is immutable" h))
-          (error 'hashtable-delete! "not a hash table" h))))
+              (die 'hashtable-delete! "hashtable is immutable" h))
+          (die 'hashtable-delete! "not a hash table" h))))
 
   (define (hashtable-entries h)
     (if (hasht? h) 
         (get-entries h)
-        (error 'hashtable-entries "not a hash table" h)))
+        (die 'hashtable-entries "not a hash table" h)))
 
   (define (hashtable-keys h)
     (if (hasht? h) 
         (get-keys h)
-        (error 'hashtable-keys "not a hash table" h)))
+        (die 'hashtable-keys "not a hash table" h)))
 
   (define (hashtable-mutable? h)
     (if (hasht? h) 
         (hasht-mutable? h)
-        (error 'hashtable-mutable? "not a hash table" h)))
+        (die 'hashtable-mutable? "not a hash table" h)))
 
   (define (hashtable-clear! h)
     (if (hasht? h) 
         (if (hasht-mutable? h)
             (clear-hash! h)
-            (error 'hashtable-clear! "hashtable is immutable" h))
-        (error 'hashtable-clear! "not a hash table" h)))
+            (die 'hashtable-clear! "hashtable is immutable" h))
+        (die 'hashtable-clear! "not a hash table" h)))
 
   (define hashtable-copy 
     (case-lambda
@@ -389,28 +389,28 @@
            (if (hasht-mutable? h) 
                (hasht-copy h #f)
                h)
-           (error 'hashtable-copy "not a hash table" h))]
+           (die 'hashtable-copy "not a hash table" h))]
       [(h mutable?)
        (if (hasht? h)
            (if (or mutable? (hasht-mutable? h))
                (hasht-copy h (and mutable? #t))
                h)
-           (error 'hashtable-copy "not a hash table" h))]))
+           (die 'hashtable-copy "not a hash table" h))]))
 
   (define (string-hash s)
     (if (string? s) 
         (foreign-call "ikrt_string_hash" s)
-        (error 'string-hash "not a string" s)))
+        (die 'string-hash "not a string" s)))
 
   (define (string-ci-hash s)
     (if (string? s) 
         (foreign-call "ikrt_string_hash" 
           (string-foldcase s))
-        (error 'string-ci-hash "not a string" s)))
+        (die 'string-ci-hash "not a string" s)))
 
   (define (symbol-hash s)
     (if (symbol? s) 
         (foreign-call "ikrt_string_hash" (symbol->string s))
-        (error 'symbol-hash "not a symbol" s)))
+        (die 'symbol-hash "not a symbol" s)))
 
 )
diff --git a/scheme/ikarus.intel-assembler.ss b/scheme/ikarus.intel-assembler.ss
index 19cd74f..1964818 100644
--- a/scheme/ikarus.intel-assembler.ss
+++ b/scheme/ikarus.intel-assembler.ss
@@ -73,7 +73,7 @@
   (lambda (x)
     (cond
       [(assq x register-mapping) => caddr]
-      [else (error 'register-index "not a register" x)])))
+      [else (die 'register-index "not a register" x)])))
 
 (define reg32?
   (lambda (x)
@@ -117,10 +117,10 @@
                         (let ([a1 ($car t)])
                            (if (null? ($cdr t)) 
                                (let () b b* ...)
-                               (error 'with-args "too many args")))
-                        (error 'with-args "too few args")))
-                 (error 'with-args "too few args")))
-           (error 'with-args "too few args")))]))
+                               (die 'with-args "too many args")))
+                        (die 'with-args "too few args")))
+                 (die 'with-args "too few args")))
+           (die 'with-args "too few args")))]))
 
 
 
@@ -209,7 +209,7 @@
        (cons (cons 'label-addr (label-name n)) ac)]
       [(foreign? n)
        (cons (cons 'foreign-label (label-name n)) ac)]
-      [else (error 'IMM32 "invalid" n)])))
+      [else (die 'IMM32 "invalid" n)])))
 
 
 (define IMM8
@@ -217,7 +217,7 @@
     (cond
       [(int? n) 
        (cons* (byte n) ac)]
-      [else (error 'IMM8 "invalid" n)])))
+      [else (die 'IMM8 "invalid" n)])))
 
 
 (define imm?
@@ -244,7 +244,7 @@
        (let ([d (cdr x)])
          (unless (and (null? (cdr d))
                       (symbol? (car d)))
-           (error 'assemble "invalid label" x)))
+           (die 'assemble "invalid label" x)))
        #t]
       [else #f])))
 
@@ -256,7 +256,7 @@
          (unless (and (null? (cdr d))
                       (or (symbol? (car d))
                           (string? (car d))))
-           (error 'assemble "invalid label-address" x)))
+           (die 'assemble "invalid label-address" x)))
        #t]
       [else #f])))
 
@@ -280,7 +280,7 @@
        (CODE c (ModRM 1 d s (IMM8 i ac)))]
       [(imm? i)
        (CODE c (ModRM 2 d s (IMM32 i ac)))]
-      [else (error 'CODErri "invalid i" i)])))
+      [else (die 'CODErri "invalid i" i)])))
 
 (define CODErr
   (lambda (c d s ac)
@@ -294,8 +294,8 @@
 (define RegReg
   (lambda (r1 r2 r3 ac)
     (cond
-      [(eq? r3 '%esp) (error 'assembler "BUG: invalid src %esp")]
-      [(eq? r1 '%ebp) (error 'assembler "BUG: invalid src %ebp")]
+      [(eq? r3 '%esp) (die 'assembler "BUG: invalid src %esp")]
+      [(eq? r1 '%ebp) (die 'assembler "BUG: invalid src %ebp")]
       [else 
        (cons*
          (byte (fxlogor 4 (fxsll (register-index r1) 3)))
@@ -314,7 +314,7 @@
       [(and (int? i1) (int? i2)) 
        ;FIXME
        (IMM32 i1 (IMM32 i2 ac))]
-      [else (error 'assemble "invalid IMM32*2" i1 i2)])))
+      [else (die 'assemble "invalid IMM32*2" i1 i2)])))
 
 (define CODErd
   (lambda (c r1 disp ac)
@@ -331,7 +331,7 @@
            (CODE c 
              (ModRM 0 r1 '/5 
                (IMM32*2 a1 a2 ac)))]
-          [else (error 'CODErd "unhandled" disp)])))))
+          [else (die 'CODErd "unhandled" disp)])))))
 
 (define CODEdi
   (lambda (c /? disp n ac)
@@ -339,14 +339,14 @@
       (lambda (a1 a2)
         (cond
           [(and (reg? a1) (reg? a2)) 
-           (error 'CODEdi "unsupported1" disp)]
+           (die 'CODEdi "unsupported1" disp)]
           [(and (imm? a1) (reg? a2))
            (CODErri c /? a2 a1 (IMM32 n ac))]
           [(and (imm? a2) (reg? a1))
            (CODErri c /? a1 a2 (IMM32 n ac))]
           [(and (imm? a1) (imm? a2))
-           (error 'CODEdi "unsupported2" disp)]
-          [else (error 'CODEdi "unhandled" disp)])))))
+           (die 'CODEdi "unsupported2" disp)]
+          [else (die 'CODEdi "unhandled" disp)])))))
 
 (define (SIB s i b ac)
   (cons (byte
@@ -376,8 +376,8 @@
                (CODE c (ModRM 1 /d '/4 (SIB 0 a0 a1 (IMM8 0 ac))))]
               [(and (imm? a0) (imm? a1))
                (CODE c (ModRM 0 /d '/5 (IMM32*2 a0 a1 ac)))]
-              [else (error 'CODE/digit "unhandled" a0 a1)])))]
-      [else (error 'CODE/digit "unhandled" dst)])))
+              [else (die 'CODE/digit "unhandled" a0 a1)])))]
+      [else (die 'CODE/digit "unhandled" dst)])))
 
 (define CODEid
   (lambda (c /? n disp ac)
@@ -385,16 +385,16 @@
       (lambda (a1 a2)
         (cond
           [(and (reg? a1) (reg? a2)) 
-           (error 'CODEid "unsupported1" disp)]
+           (die 'CODEid "unsupported1" disp)]
           [(and (imm? a1) (reg? a2))
-           (error 'CODEid "unsupported2")
+           (die 'CODEid "unsupported2")
            (CODErri c /? a2 a1 (IMM32 n ac))]
           [(and (imm? a2) (reg? a1))
-           (error 'CODEid "unsupported3")
+           (die 'CODEid "unsupported3")
            (CODErri c /? a1 a2 (IMM32 n ac))]
           [(and (imm? a1) (imm? a2))
-           (error 'CODEid "unsupported4")]
-          [else (error 'CODEid "unhandled" disp)])))))
+           (die 'CODEid "unsupported4")]
+          [else (die 'CODEid "unhandled" disp)])))))
 
 (define CODEdi8
   (lambda (c /? disp n ac)
@@ -426,20 +426,20 @@
            [(fx= n 2)
             (if (fx= (length args) 2)
                 (proc a ac (car args) (cadr args))
-                (error 'convert-instruction "incorrect args" a))]
+                (die 'convert-instruction "incorrect args" a))]
            [(fx= n 1)
             (if (fx= (length args) 1)
                 (proc a ac (car args))
-                (error 'convert-instruction "incorrect args" a))]
+                (die 'convert-instruction "incorrect args" a))]
            [(fx= n 0)
             (if (fx= (length args) 0)
                 (proc a ac)
-                (error 'convert-instruction "incorrect args" a))] 
+                (die 'convert-instruction "incorrect args" a))] 
            [else
             (if (fx= (length args) n)
                 (apply proc a ac args)
-                (error 'convert-instruction "incorrect args" a))])))]
-    [else (error 'convert-instruction "unknown instruction" a)]))
+                (die 'convert-instruction "incorrect args" a))])))]
+    [else (die 'convert-instruction "unknown instruction" a)]))
 
 
 
@@ -449,17 +449,17 @@
      (cond
        [(reg? arg2) (CODEri ircode arg2 arg1 ac)]
        [(mem? arg2) (CODEdi imcode '/0 arg2 arg1 ac)]
-       [else (error 'instr/2 "invalid args" arg1 arg2)])]
+       [else (die 'instr/2 "invalid args" arg1 arg2)])]
     [(reg? arg1)
      (cond
        [(reg? arg2) (CODErr rrcode arg1 arg2 ac)]
        [(mem? arg2) (CODErd rmcode arg1 arg2 ac)]
-       [else (error 'instr/2 "invalid args" arg1 arg2)])]
+       [else (die 'instr/2 "invalid args" arg1 arg2)])]
     [(mem? arg1)
      (cond
        [(reg? arg2) (CODErd mrcode arg2 arg1 ac)]
-       [else (error 'instr/2 "invalid args" arg1 arg2)])]
-    [else (error 'instr/2 "invalid args" arg1 arg2)]))
+       [else (die 'instr/2 "invalid args" arg1 arg2)])]
+    [else (die 'instr/2 "invalid args" arg1 arg2)]))
 
 (module ()
 (define who 'assembler)
@@ -468,7 +468,7 @@
   (cond
     [(reg8? dst)
      (CODE #x0F (CODE c (ModRM 3 '/0 dst ac)))]
-    [else (error who "invalid condition-set" dst)]))
+    [else (die who "invalid condition-set" dst)]))
 
 (define (conditional-jump c dst ac)
   (cond
@@ -476,7 +476,7 @@
      (CODE #x0F (CODE c (IMM32 dst ac)))]
     [(label? dst)
      (CODE #x0F (CODE c (cons (cons 'relative (label-name dst)) ac)))]
-    [else (error who "invalid conditional jump target" dst)]))
+    [else (die who "invalid conditional jump target" dst)]))
 
 (add-instructions instr ac
    [(ret)  (CODE #xC3 ac)]
@@ -489,67 +489,67 @@
        ((CODE/digit #xC6 '/0) dst (IMM8 src ac))]
       [(and (reg8? src) (mem? dst)) (CODErd #x88 src dst ac)]
       [(and (mem? src) (reg8? dst)) (CODErd #x8A dst src ac)]
-      [else (error who "invalid" instr)])]
+      [else (die who "invalid" instr)])]
    [(movsd src dst)
     (cond
       [(and (xmmreg? dst) (or (xmmreg? src) (mem? src)))
        (CODE #xF2 (CODE #x0F ((CODE/digit #x10 dst) src ac)))]
       [(and (xmmreg? src) (or (xmmreg? dst) (mem? dst)))
        (CODE #xF2 (CODE #x0F ((CODE/digit #x11 src) dst ac)))]
-      [else (error who "invalid" instr)])]
+      [else (die who "invalid" instr)])]
    [(cvtsi2sd src dst)
     (cond
       [(and (xmmreg? dst) (reg? src))
        (CODE #xF2 (CODE #x0F (CODE #x2A (ModRM 3 src dst ac))))]
       [(and (xmmreg? dst) (mem? src))
        (CODE #xF2 (CODE #x0F ((CODE/digit #x2A dst) src ac)))]
-      [else (error who "invalid" instr)])] 
+      [else (die who "invalid" instr)])] 
    [(cvtsd2ss src dst)
     (cond
       [(and (xmmreg? dst) (reg? src))
        (CODE #xF2 (CODE #x0F (CODE #x5A (ModRM 3 src dst ac))))]
       ;[(and (xmmreg? dst) (mem? src))
       ; (CODE #xF2 (CODE #x0F ((CODE/digit #x5A dst) src ac)))]
-      [else (error who "invalid" instr)])]
+      [else (die who "invalid" instr)])]
    [(cvtss2sd src dst)
     (cond
       [(and (xmmreg? dst) (reg? src))
        (CODE #xF3 (CODE #x0F (CODE #x5A (ModRM 3 src dst ac))))]
       ;[(and (xmmreg? dst) (mem? src))
       ; (CODE #xF3 (CODE #x0F ((CODE/digit #x5A dst) src ac)))]
-      [else (error who "invalid" instr)])]
+      [else (die who "invalid" instr)])]
    [(movss src dst)
     (cond
       [(and (xmmreg? dst) (or (xmmreg? src) (mem? src)))
        (CODE #xF3 (CODE #x0F ((CODE/digit #x10 dst) src ac)))]
       [(and (xmmreg? src) (or (xmmreg? dst) (mem? dst)))
        (CODE #xF3 (CODE #x0F ((CODE/digit #x11 src) dst ac)))]
-      [else (error who "invalid" instr)])]
+      [else (die who "invalid" instr)])]
    [(addsd src dst)
     (cond
       [(and (xmmreg? dst) (or (xmmreg? src) (mem? src)))
        (CODE #xF2 (CODE #x0F ((CODE/digit #x58 dst) src ac)))]
-      [else (error who "invalid" instr)])]
+      [else (die who "invalid" instr)])]
    [(subsd src dst)
     (cond
       [(and (xmmreg? dst) (or (xmmreg? src) (mem? src)))
        (CODE #xF2 (CODE #x0F ((CODE/digit #x5C dst) src ac)))]
-      [else (error who "invalid" instr)])]
+      [else (die who "invalid" instr)])]
    [(mulsd src dst)
     (cond
       [(and (xmmreg? dst) (or (xmmreg? src) (mem? src)))
        (CODE #xF2 (CODE #x0F ((CODE/digit #x59 dst) src ac)))]
-      [else (error who "invalid" instr)])] 
+      [else (die who "invalid" instr)])] 
    [(divsd src dst)
     (cond
       [(and (xmmreg? dst) (or (xmmreg? src) (mem? src)))
        (CODE #xF2 (CODE #x0F ((CODE/digit #x5E dst) src ac)))]
-      [else (error who "invalid" instr)])] 
+      [else (die who "invalid" instr)])] 
    [(ucomisd src dst)
     (cond
       [(and (xmmreg? dst) (or (xmmreg? src) (mem? src)))
        (CODE #x66 (CODE #x0F ((CODE/digit #x2E dst) src ac)))]
-      [else (error who "invalid" instr)])]
+      [else (die who "invalid" instr)])]
    ;[(pshufb src dst)
    ; ;;; unfortunately, this is an SSE3 instr.
    ; (cond
@@ -557,7 +557,7 @@
    ;    (CODE #x0F
    ;      (CODE #x38 
    ;        ((CODE/digit #x00 dst) src ac)))]
-   ;   [else (error who "invalid" instr)])]
+   ;   [else (die who "invalid" instr)])]
    [(addl src dst)
     (cond   
       [(and (imm8? src) (reg? dst)) 
@@ -574,7 +574,7 @@
        ((CODE/digit #x81 '/0) dst (IMM32 src ac))]
       [(and (reg? src) (mem? dst))
        ((CODE/digit #x01 src) dst ac)]
-      [else (error who "invalid" instr)])]
+      [else (die who "invalid" instr)])]
    [(subl src dst)
     (cond   
       [(and (imm8? src) (reg? dst)) 
@@ -591,7 +591,7 @@
        ((CODE/digit #x81 '/5) dst (IMM32 src ac))]
       [(and (reg? src) (mem? dst))
        ((CODE/digit #x29 src) dst ac)]
-      [else (error who "invalid" instr)])]
+      [else (die who "invalid" instr)])]
    [(sall src dst)
     (cond
       [(and (equal? 1 src) (reg? dst))
@@ -604,7 +604,7 @@
        (CODE #xD3 (ModRM 3 '/4 dst ac))]
       [(and (eq? src '%cl) (mem? dst))
        ((CODE/digit #xD3 '/4) dst ac)]
-      [else (error who "invalid" instr)])]
+      [else (die who "invalid" instr)])]
    [(shrl src dst)
     (cond
       [(and (equal? 1 src) (reg? dst))
@@ -617,7 +617,7 @@
        ((CODE/digit #xC1 '/5) dst (IMM8 src ac))]
       [(and (eq? src '%cl) (mem? dst))
        ((CODE/digit #xD3 '/5) dst ac)]
-      [else (error who "invalid" instr)])]
+      [else (die who "invalid" instr)])]
    [(sarl src dst)
     (cond
       [(and (equal? 1 src) (reg? dst))
@@ -630,7 +630,7 @@
        (CODE #xD3 (ModRM 3 '/7 dst ac))]
       [(and (eq? src '%cl) (mem? dst))
        ((CODE/digit #xD3 '/7) dst ac)]
-      [else (error who "invalid" instr)])]
+      [else (die who "invalid" instr)])]
    [(andl src dst) 
     (cond
       [(and (imm? src) (mem? dst))
@@ -647,7 +647,7 @@
        ((CODE/digit #x21 src) dst ac)]
       [(and (mem? src) (reg? dst))
        (CODErd #x23 dst src ac)]
-      [else (error who "invalid" instr)])]
+      [else (die who "invalid" instr)])]
    [(orl src dst) 
     (cond
       [(and (imm? src) (mem? dst))
@@ -664,7 +664,7 @@
        (CODE #x09 (ModRM 3 src dst ac))]
       [(and (mem? src) (reg? dst))
        (CODErd #x0B dst src ac)]
-      [else (error who "invalid" instr)])]
+      [else (die who "invalid" instr)])]
    [(xorl src dst) 
     (cond
       [(and (imm8? src) (reg? dst)) 
@@ -681,12 +681,12 @@
        ((CODE/digit #x31 src) dst ac)]
       ;[(and (imm? src) (mem? dst))
       ; ((CODE/digit #x81 '/6) dst (IMM32 src ac))]
-      [else (error who "invalid" instr)])]
+      [else (die who "invalid" instr)])]
    [(leal src dst) 
     (cond
       [(and (mem? src) (reg? dst))
        (CODErd #x8D dst src ac)]
-      [else (error who "invalid" instr)])]
+      [else (die who "invalid" instr)])]
    [(cmpl src dst)
     (cond
       [(and (imm8? src) (reg? dst)) 
@@ -700,12 +700,12 @@
       [(and (mem? src) (reg? dst))
        (CODErd #x3B dst src ac)]
       [(and (imm8? src) (mem? dst))
-       ;;; maybe error 
+       ;;; maybe die 
        (CODErd #x83 '/7 dst (IMM8 src ac))]
       [(and (imm? src) (mem? dst))
-       ;;; maybe error 
+       ;;; maybe die 
        (CODErd #x81 '/7 dst (IMM32 src ac))]
-      [else (error who "invalid" instr)])]
+      [else (die who "invalid" instr)])]
    [(imull src dst)
     (cond
       [(and (imm8? src) (reg? dst)) 
@@ -716,15 +716,15 @@
        (CODE #x0F (CODE #xAF (ModRM 3 dst src ac)))]
       [(and (mem? src) (reg? dst))
        (CODE #x0F (CODErd #xAF dst src ac))]
-      [else (error who "invalid" instr)])]
+      [else (die who "invalid" instr)])]
    [(idivl dst)
     (cond
       [(reg? dst)
        (CODErr #xF7 '/7 dst ac)]
       [(mem? dst)
-       ;;; maybe error 
+       ;;; maybe die 
        (CODErd #xF7 '/7 dst ac)]
-      [else (error who "invalid" instr)])]
+      [else (die who "invalid" instr)])]
    [(pushl dst)
     (cond
       [(imm8? dst) 
@@ -734,35 +734,35 @@
       [(reg? dst)
        (CODE+r #x50 dst ac)]
       [(mem? dst)
-       ;;; maybe error 
+       ;;; maybe die 
        (CODErd #xFF '/6 dst ac)]
-      [else (error who "invalid" instr)])] 
+      [else (die who "invalid" instr)])] 
    [(popl dst)
     (cond
       [(reg? dst)
        (CODE+r #x58 dst ac)]
       [(mem? dst)
-       ;;; maybe error 
+       ;;; maybe die 
        (CODErd #x8F '/0 dst ac)]
-      [else (error who "invalid" instr)])] 
+      [else (die who "invalid" instr)])] 
    [(notl dst)
     (cond
       [(reg? dst)
        (CODE #xF7 (ModRM 3 '/2 dst ac))]
       [(mem? dst)
-       ;;; maybe error 
+       ;;; maybe die 
        (CODErd #xF7 '/7 dst ac)]
-      [else (error who "invalid" instr)])]
+      [else (die who "invalid" instr)])]
    [(bswap dst)
     (cond
       [(reg? dst) 
        (CODE #x0F (CODE+r #xC8 dst ac))]
-      [else (error who "invalid" instr)])]
+      [else (die who "invalid" instr)])]
    [(negl dst)
     (cond
       [(reg? dst)
        (CODE #xF7 (ModRM 3 '/3 dst ac))]
-      [else (error who "invalid" instr)])]
+      [else (die who "invalid" instr)])]
    [(jmp dst)
     (cond
       [(label? dst)
@@ -770,9 +770,9 @@
       [(imm? dst) 
        (CODE #xE9 (IMM32 dst ac))]
       [(mem? dst)
-       ;;; maybe error 
+       ;;; maybe die 
        (CODErd #xFF '/4 dst ac)]
-      [else (error who "invalid jmp target" dst)])]
+      [else (die who "invalid jmp target" dst)])]
    [(call dst)
     (cond
       [(imm? dst) 
@@ -780,11 +780,11 @@
       [(label? dst)
        (CODE #xE8 (cons (cons 'relative (label-name dst)) ac))]
       [(mem? dst)
-       ;;; maybe error 
+       ;;; maybe die 
        (CODErd #xFF '/2 dst ac)]
       [(reg? dst)
        (CODE #xFF (ModRM 3 '/2 dst ac))]
-      [else (error who "invalid jmp target" dst)])]
+      [else (die who "invalid jmp target" dst)])]
    [(seta dst)   (conditional-set  #x97 dst ac)]
    [(setae dst)  (conditional-set  #x93 dst ac)]
    [(setb dst)   (conditional-set  #x92 dst ac)]
@@ -825,15 +825,15 @@
    [(jp dst)     (conditional-jump #x8A dst ac)]
    [(jnp dst)    (conditional-jump #x8B dst ac)]
    [(byte x)
-    (unless (byte? x) (error who "not a byte" x))
+    (unless (byte? x) (die who "not a byte" x))
     (cons (byte x) ac)]
    [(byte-vector x) (append (map (lambda (x) (byte x)) (vector->list x)) ac)]
    [(int a) (IMM32 a ac)]
    [(label L)
-    (unless (symbol? L) (error who "label is not a symbol" L))
+    (unless (symbol? L) (die who "label is not a symbol" L))
     (cons (cons 'label L) ac)]
    [(label-address L)
-    (unless (symbol? L) (error who "label-address is not a symbol" L))
+    (unless (symbol? L) (die who "label-address is not a symbol" L))
     (cons (cons 'label-addr L) ac)]
    [(current-frame-offset)
     (cons '(current-frame-offset) ac)]
@@ -853,7 +853,7 @@
                     relative local-relative current-frame-offset)
                    (fx+ ac 4)]
                   [(label) ac]
-                  [else (error 'compute-code-size "unknown instr" x)])))
+                  [else (die 'compute-code-size "unknown instr" x)])))
           0 
           ls)))
 
@@ -861,13 +861,13 @@
 (define set-label-loc!
   (lambda (x loc)
     (when (getprop x '*label-loc*)
-      (error 'compile "label is already defined" x))
+      (die 'compile "label is already defined" x))
     (putprop x '*label-loc* loc)))
 
 (define label-loc
   (lambda (x)
     (or (getprop x '*label-loc*)
-        (error 'compile "undefined label" x))))
+        (die 'compile "undefined label" x))))
 
 
 (define unset-label-loc!
@@ -883,7 +883,7 @@
        (code-set! code (fx+ idx 1) (fxlogand (fxsra x 6) #xFF))
        (code-set! code (fx+ idx 2) (fxlogand (fxsra x 14) #xFF))
        (code-set! code (fx+ idx 3) (fxlogand (fxsra x 22) #xFF))]
-      [else (error 'set-code-word! "unhandled" x)])))
+      [else (die 'set-code-word! "unhandled" x)])))
  
 (define (optimize-local-jumps ls)
   (define locals '())
@@ -937,7 +937,7 @@
                    (set-label-loc! (cdr a) (list x idx))
                    (f (cdr ls) idx reloc)]
                   [else
-                   (error 'whack-instructions "unknown instr" a)])))])))
+                   (die 'whack-instructions "unknown instr" a)])))])))
     (f ls 0 '())))
 
 (define wordsize 4)
@@ -952,7 +952,7 @@
                   [(reloc-word foreign-label)        (fx+ ac 2)]
                   [(relative reloc-word+ label-addr) (fx+ ac 3)]
                   [(word byte label current-frame-offset local-relative) ac]
-                  [else (error 'compute-reloc-size "unknown instr" x)])))
+                  [else (die 'compute-reloc-size "unknown instr" x)])))
           0 
           ls)))
 
@@ -972,7 +972,7 @@
 (define code-entry-adjustment
   (let ([v #f])
     (case-lambda
-      [() (or v (error 'code-entry-adjustment "uninitialized"))]
+      [() (or v (die 'code-entry-adjustment "uninitialized"))]
       [(x) (set! v x)])))
 
 (define whack-reloc
@@ -990,7 +990,7 @@
                         [(fx= (length p) 2)
                          (let ([code (car p)] [idx (cadr p)])
                            (unless (fx= idx 0)
-                             (error 'whack-reloc 
+                             (die 'whack-reloc 
                                "cannot create a thunk pointing"
                                idx))
                            (let ([thunk (code->thunk code)])
@@ -1009,7 +1009,7 @@
            (let ([name 
                   (if (string? v)
                       (foreign-string->bytevector v)
-                      (error 'whack-reloc "not a string" v))])
+                      (die 'whack-reloc "not a string" v))])
              (vector-set! vec reloc-idx (fxlogor 1 (fxsll idx 2)))
              (vector-set! vec (fx+ reloc-idx 1) name)
              (set! reloc-idx (fx+ reloc-idx 2)))]
@@ -1031,7 +1031,7 @@
            (let ([loc (label-loc v)])
              (let ([obj (car loc)] [disp (cadr loc)])
                (unless (eq? obj code)
-                 (error 'whack-reloc "local-relative differ"))
+                 (die 'whack-reloc "local-relative differ"))
                (let ([rel (fx- disp (fx+ idx 4))])
                  (code-set! code (fx+ idx 0) (fxlogand rel #xFF))
                  (code-set! code (fx+ idx 1) (fxlogand (fxsra rel 8) #xFF))
@@ -1041,13 +1041,13 @@
            (let ([loc (label-loc v)])
              (let ([obj (car loc)] [disp (cadr loc)])
                (unless (and (code? obj) (fixnum? disp))
-                 (error 'whack-reloc "invalid relative jump obj/disp" obj disp))
+                 (die 'whack-reloc "invalid relative jump obj/disp" obj disp))
                (vector-set! vec reloc-idx (fxlogor 3 (fxsll idx 2)))
                (vector-set! vec (fx+ reloc-idx 1) 
                  (fx+ disp (code-entry-adjustment)))
                (vector-set! vec (fx+ reloc-idx 2) obj)))
            (set! reloc-idx (fx+ reloc-idx 3))]
-          [else (error 'whack-reloc "invalid reloc type" type)]))
+          [else (die 'whack-reloc "invalid reloc type" type)]))
       )))
 
 
diff --git a/scheme/ikarus.io.ss b/scheme/ikarus.io.ss
index 76db540..bf8fbbd 100644
--- a/scheme/ikarus.io.ss
+++ b/scheme/ikarus.io.ss
@@ -164,7 +164,7 @@
     (syntax-rules ()
       [(_ name)
        (define (name . args) 
-         (apply error 'name "not implemented" args))]))
+         (apply die 'name "not implemented" args))]))
 
  
   (define-syntax u8?
@@ -223,17 +223,17 @@
   (define (input-port-name p)
     (if (input-port? p) 
         ($port-id p)
-        (error 'input-port-name "not an input port" p)))
+        (die 'input-port-name "not an input port" p)))
 
   (define (output-port-name p)
     (if (output-port? p) 
         ($port-id p)
-        (error 'output-port-name "not an output port" p)))
+        (die 'output-port-name "not an output port" p)))
 
   (define (port-id p)
     (if (port? p) 
         ($port-id p)
-        (error 'port-id "not a port" p)))
+        (die 'port-id "not a port" p)))
 
   (define guarded-port
     (let ([G (make-guardian)])
@@ -266,11 +266,11 @@
     ;;; FIXME: get-position and set-position! are ignored for now
     (define who 'make-custom-binary-input-port)
     (unless (string? id)
-      (error who "id is not a string" id))
+      (die who "id is not a string" id))
     (unless (procedure? read!)
-      (error who "read! is not a procedure" read!))
+      (die who "read! is not a procedure" read!))
     (unless (or (procedure? close) (not close))
-      (error who "close should be either a procedure or #f" close))
+      (die who "close should be either a procedure or #f" close))
     ($make-custom-binary-port 
       binary-input-port-bits
       0
@@ -282,11 +282,11 @@
     ;;; FIXME: get-position and set-position! are ignored for now
     (define who 'make-custom-binary-output-port)
     (unless (string? id)
-      (error who "id is not a string" id))
+      (die who "id is not a string" id))
     (unless (procedure? write!)
-      (error who "write! is not a procedure" write!))
+      (die who "write! is not a procedure" write!))
     (unless (or (procedure? close) (not close))
-      (error who "close should be either a procedure or #f" close))
+      (die who "close should be either a procedure or #f" close))
     ($make-custom-binary-port 
       binary-output-port-bits
       256
@@ -298,11 +298,11 @@
     ;;; FIXME: get-position and set-position! are ignored for now
     (define who 'make-custom-textual-input-port)
     (unless (string? id)
-      (error who "id is not a string" id))
+      (die who "id is not a string" id))
     (unless (procedure? read!)
-      (error who "read! is not a procedure" read!))
+      (die who "read! is not a procedure" read!))
     (unless (or (procedure? close) (not close))
-      (error who "close should be either a procedure or #f" close))
+      (die who "close should be either a procedure or #f" close))
     ($make-custom-textual-port 
       (fxior textual-input-port-bits fast-char-text-tag)
       0
@@ -314,11 +314,11 @@
     ;;; FIXME: get-position and set-position! are ignored for now
     (define who 'make-custom-textual-output-port)
     (unless (string? id)
-      (error who "id is not a string" id))
+      (die who "id is not a string" id))
     (unless (procedure? write!)
-      (error who "write! is not a procedure" write!))
+      (die who "write! is not a procedure" write!))
     (unless (or (procedure? close) (not close))
-      (error who "close should be either a procedure or #f" close))
+      (die who "close should be either a procedure or #f" close))
     ($make-custom-textual-port 
       (fxior textual-output-port-bits fast-char-text-tag)
       256
@@ -355,11 +355,11 @@
       [(bv) (open-bytevector-input-port bv #f)]
       [(bv maybe-transcoder) 
        (unless (bytevector? bv) 
-         (error 'open-bytevector-input-port 
+         (die 'open-bytevector-input-port 
                 "not a bytevector" bv))
        (when (and maybe-transcoder
                   (not (transcoder? maybe-transcoder)))
-         (error 'open-bytevector-input-port 
+         (die 'open-bytevector-input-port 
                 "not a transcoder" maybe-transcoder))
        ($make-port 
           (input-transcoder-attrs maybe-transcoder)
@@ -379,7 +379,7 @@
       [(transcoder) 
        (define who 'open-bytevector-output-port)
        (unless (or (not transcoder) (transcoder? transcoder))
-         (error who "invalid transcoder value" transcoder))
+         (die who "invalid transcoder value" transcoder))
        (let ([buf* '()] [buffer-size 256])
          (let ([p 
                 ($make-port 
@@ -424,9 +424,9 @@
       [(proc transcoder) 
        (define who 'call-with-bytevector-output-port)
        (unless (procedure? proc) 
-         (error who "not a procedure" proc))
+         (die who "not a procedure" proc))
        (unless (or (not transcoder) (transcoder? transcoder))
-         (error who "invalid transcoder argument" transcoder))
+         (die who "invalid transcoder argument" transcoder))
        (let-values ([(p extract) 
                      (open-bytevector-output-port transcoder)])
          (proc p)
@@ -435,7 +435,7 @@
   (define (call-with-string-output-port proc)
     (define who 'call-with-string-output-port)
     (unless (procedure? proc) 
-      (error who "not a procedure" proc))
+      (die who "not a procedure" proc))
     (let-values ([(p extract) (open-string-output-port)])
       (proc p)
       (extract)))
@@ -482,7 +482,7 @@
 
   (define (open-string-input-port str)
     (unless (string? str) 
-      (error 'open-string-input-port str))
+      (die 'open-string-input-port str))
     ($make-port 
        (fxior textual-input-port-bits fast-char-text-tag)
        0 (string-length str) str
@@ -499,10 +499,10 @@
   (define (transcoded-port p transcoder)
     (define who 'transcoded-port)
     (unless (transcoder? transcoder)
-      (error who "not a transcoder" transcoder))
-    (unless (port? p) (error who "not a port" p))
-    (when ($port-transcoder p) (error who "not a binary port" p))
-    (when ($port-closed? p) (error who "cannot transcode closed port" p))
+      (die who "not a transcoder" transcoder))
+    (unless (port? p) (die who "not a port" p))
+    (when ($port-transcoder p) (die who "not a binary port" p))
+    (when ($port-closed? p) (die who "cannot transcode closed port" p))
     (let ([read! ($port-read! p)]
           [write! ($port-write! p)])
       ($mark-port-closed! p)
@@ -512,7 +512,7 @@
             [read! (input-transcoder-attrs transcoder)]
             [write! (output-transcoder-attrs transcoder)]
             [else
-             (error 'transcoded-port 
+             (die 'transcoded-port 
                "port is neither input nor output!")])
           ($port-index p)
           ($port-size p)
@@ -529,13 +529,13 @@
   (define (reset-input-port! p)
     (if (input-port? p) 
         ($set-port-index! p ($port-size p))
-        (error 'reset-input-port! "not an input port" p)))
+        (die 'reset-input-port! "not an input port" p)))
 
   (define (port-transcoder p)
     (if (port? p)
         (let ([tr ($port-transcoder p)])
           (and (transcoder? tr) tr))
-        (error 'port-transcoder "not a port" p)))
+        (die 'port-transcoder "not a port" p)))
               
   (define ($port-closed? p) 
     (not (fxzero? (fxand ($port-attrs p) closed-port-tag))))
@@ -550,7 +550,7 @@
         (if (fxzero? (fxand ($port-attrs p) r6rs-mode-tag))
             'ikarus-mode
             'r6rs-mode)
-        (error 'port-mode "not a port" p)))
+        (die 'port-mode "not a port" p)))
 
   (define (set-port-mode! p mode)
     (if (port? p) 
@@ -561,8 +561,8 @@
           [(ikarus-mode)
            ($set-port-attrs! p
              (fxand ($port-attrs p) (fxnot r6rs-mode-tag)))]
-          [else (error 'set-port-mode! "invalid mode" mode)])
-        (error 'set-port-mode! "not a port" p)))
+          [else (die 'set-port-mode! "invalid mode" mode)])
+        (die 'set-port-mode! "not a port" p)))
 
 
   (define flush-output-port
@@ -570,22 +570,22 @@
       [() (flush-output-port (*the-output-port*))] 
       [(p)
        (unless (output-port? p) 
-         (error 'flush-output-port "not an output port" p))
+         (die 'flush-output-port "not an output port" p))
        (when ($port-closed? p) 
-         (error 'flush-output-port "port is closed" p))
+         (die 'flush-output-port "port is closed" p))
        (let ([idx ($port-index p)]
              [buf ($port-buffer p)])
          (unless (fx= idx 0)
            (let ([bytes (($port-write! p) buf 0 idx)])
              (unless (and (fixnum? bytes) (fx>= bytes 0) (fx<= bytes idx))
-               (error 'flush-output-port 
+               (die 'flush-output-port 
                       "write! returned an invalid value" 
                       bytes))
              (cond
                [(fx= bytes idx) 
                 ($set-port-index! p 0)]
                [(fx= bytes 0) 
-                (error 'flush-output-port "could not write bytes to sink")]
+                (die 'flush-output-port "could not write bytes to sink")]
                [else
                 (bytevector-copy! buf bytes buf 0 (fx- idx bytes))
                 ($set-port-index! p (fx- idx bytes))
@@ -604,17 +604,17 @@
 
   (define (close-port p)
     (unless (port? p)
-       (error 'close-port "not a port" p))
+       (die 'close-port "not a port" p))
     ($close-port p))
 
   (define (close-input-port p)
     (unless (input-port? p)
-       (error 'close-input-port "not an input port" p))
+       (die 'close-input-port "not an input port" p))
     ($close-port p))
 
   (define (close-output-port p)
     (unless (output-port? p)
-       (error 'close-output-port "not an output port" p))
+       (die 'close-output-port "not an output port" p))
     ($close-port p))
 
   ;(define-rrr port-has-port-position?)
@@ -626,39 +626,39 @@
   (module (get-char lookahead-char)
     (import UNSAFE)
     (define (refill-bv-start p who)
-      (when ($port-closed? p) (error who "port is closed" p))
+      (when ($port-closed? p) (die who "port is closed" p))
       (let* ([bv ($port-buffer p)]
              [n (bytevector-length bv)])
         (let ([j (($port-read! p) bv 0 n)])
           (unless (fixnum? j)
-            (error who "invalid return value from read! procedure" j))
+            (die who "invalid return value from read! procedure" j))
           (cond
             [(fx>= j 0)
              (unless (fx<= j n)
-               (error who "read! returned a value out of range" j))
+               (die who "read! returned a value out of range" j))
              ($set-port-index! p 0)
              ($set-port-size! p j)
              j]
             [else 
-             (error who "read! returned a value out of range" j)]))))
+             (die who "read! returned a value out of range" j)]))))
     (define (refill-bv-buffer p who)
-      (when ($port-closed? p) (error who "port is closed" p))
+      (when ($port-closed? p) (die who "port is closed" p))
       (let ([bv ($port-buffer p)] [i ($port-index p)] [j ($port-size p)])
         (let ([c0 (fx- j i)])
           (bytevector-copy! bv i bv 0 c0)
           (let* ([max (fx- (bytevector-length bv) c0)]
                  [c1 (($port-read! p) bv c0 max)])
             (unless (fixnum? c1)
-              (error who "invalid return value from read! procedure" c1))
+              (die who "invalid return value from read! procedure" c1))
             (cond
               [(fx>= j 0)
                (unless (fx<= j max)
-                 (error who "read! returned a value out of range" j))
+                 (die who "read! returned a value out of range" j))
                ($set-port-index! p c0)
                ($set-port-size! p (fx+ c1 c0))
                c1]
               [else 
-               (error who "read! returned a value out of range" c1)])))))
+               (die who "read! returned a value out of range" c1)])))))
     (define (get-char-latin-mode p who idx)
       (let ([n (refill-bv-start p who)])
         (cond
@@ -674,7 +674,7 @@
           [(replace) #\xFFFD]
           [(raise)
            (raise (make-i/o-decoding-error p))]
-          [else (error who "cannot happen")]))
+          [else (die who "cannot happen")]))
       (let ([i ($port-index p)] 
             [j ($port-size p)]
             [buf ($port-buffer p)])
@@ -777,7 +777,7 @@
           [(replace) #\xFFFD]
           [(raise)
            (raise (make-i/o-decoding-error p))]
-          [else (error who "cannot happen")]))
+          [else (die who "cannot happen")]))
       (let ([i ($port-index p)] 
             [j ($port-size p)]
             [buf ($port-buffer p)])
@@ -890,26 +890,26 @@
     (define (speedup-input-port p who)
       ;;; returns #t if port is eof, #f otherwise
       (unless (input-port? p) 
-        (error who "not an input port" p))
+        (die who "not an input port" p))
       (let ([tr ($port-transcoder p)])
         (unless tr 
-          (error who "not a textual port" p))
+          (die who "not a textual port" p))
         (case (transcoder-codec tr)
           [(utf-8-codec)
            ;;;
            ($set-port-attrs! p 
              (fxior textual-input-port-bits fast-u7-text-tag))
            (eof-object? (advance-bom p who '(#xEF #xBB #xBF)))]
-          [else (error 'slow-get-char "codec not handled")])))
+          [else (die 'slow-get-char "codec not handled")])))
 
     (define (lookahead-char-char-mode p who)
       (let ([str ($port-buffer p)]
             [read! ($port-read! p)])
         (let ([n (read! str 0 (string-length str))])
           (unless (fixnum? n) 
-            (error who "invalid return value from read!" n))
+            (die who "invalid return value from read!" n))
           (unless (<= 0 n (string-length str))
-            (error who "return value from read! is out of range" n))
+            (die who "return value from read! is out of range" n))
           ($set-port-index! p 0) 
           ($set-port-size! p n)
           (cond
@@ -957,9 +957,9 @@
             [read! ($port-read! p)])
         (let ([n (read! str 0 (string-length str))])
           (unless (fixnum? n) 
-            (error who "invalid return value from read!" n))
+            (die who "invalid return value from read!" n))
           (unless (<= 0 n (string-length str))
-            (error who "return value from read! is out of range" n))
+            (die who "return value from read! is out of range" n))
           ($set-port-size! p n)
           (cond
             [(fx= n 0)
@@ -1008,31 +1008,31 @@
 
   ;;; ----------------------------------------------------------
   (define (assert-binary-input-port p who)
-    (unless (port? p) (error who "not a port" p))
-    (when ($port-closed? p) (error who "port is closed" p))
-    (when ($port-transcoder p) (error who "port is not binary" p))
+    (unless (port? p) (die who "not a port" p))
+    (when ($port-closed? p) (die who "port is closed" p))
+    (when ($port-transcoder p) (die who "port is not binary" p))
     (unless ($port-read! p)
-      (error who "port is not an input port" p)))
+      (die who "port is not an input port" p)))
 
   (module (get-u8 lookahead-u8)
     (import UNSAFE)
     (define (get-u8-byte-mode p who start) 
-      (when ($port-closed? p) (error who "port is closed" p))
+      (when ($port-closed? p) (die who "port is closed" p))
       (let* ([bv ($port-buffer p)]
              [n (bytevector-length bv)])
         (let ([j (($port-read! p) bv 0 n)])
           (unless (fixnum? j)
-            (error who "invalid return value from read! procedure" j))
+            (die who "invalid return value from read! procedure" j))
           (cond
             [(fx> j 0) 
              (unless (fx<= j n)
-               (error who "read! returned a value out of range" j))
+               (die who "read! returned a value out of range" j))
              ($set-port-index! p start) 
              ($set-port-size! p j)
              (bytevector-u8-ref bv 0)]
             [(fx= j 0) (eof-object)]
             [else 
-             (error who "read! returned a value out of range" j)]))))
+             (die who "read! returned a value out of range" j)]))))
     (define (slow-get-u8 p who start) 
       (assert-binary-input-port p who)
       ($set-port-attrs! p fast-get-byte-tag)
@@ -1075,14 +1075,14 @@
                  (eof-object? (lookahead-u8 p))))]
         [(input-port? p)
          (when ($port-closed? p) 
-           (error 'port-eof? "port is closed" p))
+           (die 'port-eof? "port is closed" p))
          (if (textual-port? p) 
              (eof-object? (lookahead-char p))
              (eof-object? (lookahead-u8 p)))]
-        [else (error 'port-eof? "not an input port" p)])))
+        [else (die 'port-eof? "not an input port" p)])))
 
   (define io-errors-vec
-    '#("unknown error"
+    '#("unknown die"
        "bad file name"
        "operation interrupted"
        "not a directory"
@@ -1098,7 +1098,7 @@
        "operation not supported"
        "not enough space on device"
        "quota exceeded"
-       "io error"
+       "io die"
        "device is busy"
        "access fault"
        "file already exists"
@@ -1110,9 +1110,10 @@
              (cond
                [(fx< err (vector-length io-errors-vec))
                 (vector-ref io-errors-vec err)]
-               [else "unknown error"]))])
+               [else "unknown die"]))])
       (raise 
         (condition
+          (make-error)
           (make-who-condition who)
           (make-message-condition msg)
           (make-i/o-filename-error id)))))
@@ -1186,7 +1187,7 @@
                  [(fo:no-truncate/no-create)         5]
                  [(fo:no-truncate/no-fail)           6]
                  [(fo:no-truncate/no-fail/no-create) 7]
-                 [else (error who "invalid file option" file-options)])])
+                 [else (die who "invalid file option" file-options)])])
       (let ([fh (foreign-call "ikrt_open_output_fd"
                    (string->utf8 filename)
                    opt)])
@@ -1204,9 +1205,9 @@
        (open-file-input-port filename file-options buffer-mode #f)]
       [(filename file-options buffer-mode transcoder)
        (unless (string? filename)
-         (error 'open-file-input-port "invalid filename" filename))
+         (die 'open-file-input-port "invalid filename" filename))
        (unless (or (not transcoder) (transcoder? transcoder)) 
-         (error 'open-file-input-port "invalid transcoder" transcoder))
+         (die 'open-file-input-port "invalid transcoder" transcoder))
        ; FIXME: file-options ignored
        ; FIXME: buffer-mode ignored
        (fh->input-port 
@@ -1227,11 +1228,11 @@
        (open-file-output-port filename file-options buffer-mode #f)]
       [(filename file-options buffer-mode transcoder)
        (unless (string? filename)
-         (error 'open-file-output-port "invalid filename" filename))
+         (die 'open-file-output-port "invalid filename" filename))
        ; FIXME: file-options ignored
        ; FIXME: buffer-mode ignored
        (unless (or (not transcoder) (transcoder? transcoder)) 
-         (error 'open-file-output-port "invalid transcoder" transcoder))
+         (die 'open-file-output-port "invalid transcoder" transcoder))
        (fh->output-port
          (open-output-file-handle filename file-options 
             'open-file-output-port)
@@ -1242,7 +1243,7 @@
 
   (define (open-output-file filename)
     (unless (string? filename)
-      (error 'open-output-file "invalid filename" filename))
+      (die 'open-output-file "invalid filename" filename))
     (fh->output-port 
        (open-output-file-handle filename (file-options) 
           'open-input-file)
@@ -1253,7 +1254,7 @@
 
   (define (open-input-file filename)
     (unless (string? filename)
-      (error 'open-input-file "invalid filename" filename))
+      (die 'open-input-file "invalid filename" filename))
     (fh->input-port 
        (open-input-file-handle filename 'open-input-file) 
        filename
@@ -1263,9 +1264,9 @@
 
   (define (call-with-input-file filename proc)
     (unless (string? filename)
-      (error 'call-with-input-file "invalid filename" filename))
+      (die 'call-with-input-file "invalid filename" filename))
     (unless (procedure? proc)
-      (error 'call-with-input-file "not a procedure" proc))
+      (die 'call-with-input-file "not a procedure" proc))
     (call-with-port
       (fh->input-port 
         (open-input-file-handle filename 'call-with-input-file) 
@@ -1277,9 +1278,9 @@
 
   (define (with-input-from-file filename proc)
     (unless (string? filename)
-      (error 'with-input-from-file "invalid filename" filename))
+      (die 'with-input-from-file "invalid filename" filename))
     (unless (procedure? proc)
-      (error 'with-input-from-file "not a procedure" proc))
+      (die 'with-input-from-file "not a procedure" proc))
     (let ([p
            (fh->input-port 
              (open-input-file-handle filename 'with-input-from-file)
@@ -1340,8 +1341,8 @@
               void
               (lambda () (proc p))
               (lambda () (close-port p)))
-            (error 'call-with-port "not a procedure" proc))
-        (error 'call-with-port "not a port" p)))
+            (die 'call-with-port "not a procedure" proc))
+        (die 'call-with-port "not a port" p)))
 
   (define read-char
     (case-lambda
@@ -1350,8 +1351,8 @@
        (if (input-port? p)
            (if (textual-port? p)
                (get-char p)
-               (error 'read-char "not a textual port" p))
-           (error 'read-char "not an input-port" p))]))
+               (die 'read-char "not a textual port" p))
+           (die 'read-char "not an input-port" p))]))
   ;;;
   (define peek-char
     (case-lambda
@@ -1360,8 +1361,8 @@
        (if (input-port? p)
            (if (textual-port? p)
                (lookahead-char p)
-               (error 'peek-char "not a textual port" p))
-           (error 'peek-char "not an input-port" p))]))
+               (die 'peek-char "not a textual port" p))
+           (die 'peek-char "not an input-port" p))]))
 
   (define (get-bytevector-n p n) 
     (import (ikarus system $fx) (ikarus system $bytevectors))
@@ -1374,11 +1375,11 @@
                 p
                 (f s n p))))))
     (unless (input-port? p) 
-      (error 'get-bytevector-n "not an input port" p))
+      (die 'get-bytevector-n "not an input port" p))
     (unless (binary-port? p)
-      (error 'get-bytevector-n "not a binary port" p))
+      (die 'get-bytevector-n "not a binary port" p))
     (unless (fixnum? n) 
-      (error 'get-bytevector-n "count is not a fixnum" n))
+      (die 'get-bytevector-n "count is not a fixnum" n))
     (cond
       [($fx> n 0) 
        (let ([s ($make-bytevector n)])
@@ -1396,30 +1397,30 @@
                       s
                       (f p n s i)))]))))]
       [($fx= n 0) '#vu8()]
-      [else (error 'get-bytevector-n "count is negative" n)]))
+      [else (die 'get-bytevector-n "count is negative" n)]))
 
   (define (get-bytevector-n! p s i c) 
     (import (ikarus system $fx) (ikarus system $bytevectors))
     (unless (input-port? p) 
-      (error 'get-bytevector-n! "not an input port" p))
+      (die 'get-bytevector-n! "not an input port" p))
     (unless (binary-port? p)
-      (error 'get-bytevector-n! "not a binary port" p))
+      (die 'get-bytevector-n! "not a binary port" p))
     (unless (bytevector? s) 
-      (error 'get-bytevector-n! "not a bytevector" s))
+      (die 'get-bytevector-n! "not a bytevector" s))
     (let ([len ($bytevector-length s)])
       (unless (fixnum? i) 
-        (error 'get-bytevector-n! "starting index is not a fixnum" i))
+        (die 'get-bytevector-n! "starting index is not a fixnum" i))
       (when (or ($fx< i 0) ($fx> i len))
-        (error 'get-bytevector-n! 
+        (die 'get-bytevector-n! 
           (format "starting index is out of range 0..~a" len)
           i))
       (unless (fixnum? c)
-        (error 'get-bytevector-n! "count is not a fixnum" c))
+        (die 'get-bytevector-n! "count is not a fixnum" c))
       (cond
         [($fx> c 0)
          (let ([j (+ i c)])
            (when (> j len)
-             (error 'get-bytevector-n! 
+             (die 'get-bytevector-n! 
                (format "count is out of range 0..~a" (- len i))
                c))
            (let ([x (get-u8 p)])
@@ -1438,7 +1439,7 @@
                              i
                              (f p s start i c)))])))])))]
         [($fx= c 0) 0]
-        [else (error 'get-bytevector-n! "count is negative" c)])))
+        [else (die 'get-bytevector-n! "count is negative" c)])))
 
   (define-rrr get-bytevector-some)
 
@@ -1462,17 +1463,17 @@
     (if (input-port? p)
         (if (binary-port? p)
             (get-it p)
-            (error 'get-bytevector-all "not a binary port" p))
-        (error 'get-bytevector-all "not an input port" p)))
+            (die 'get-bytevector-all "not a binary port" p))
+        (die 'get-bytevector-all "not an input port" p)))
 
   (define (get-string-n p n) 
     (import (ikarus system $fx) (ikarus system $strings))
     (unless (input-port? p) 
-      (error 'get-string-n "not an input port" p))
+      (die 'get-string-n "not an input port" p))
     (unless (textual-port? p) 
-      (error 'get-string-n "not a textual port" p))
+      (die 'get-string-n "not a textual port" p))
     (unless (fixnum? n) 
-      (error 'get-string-n "count is not a fixnum" n))
+      (die 'get-string-n "count is not a fixnum" n))
     (cond
       [($fx> n 0) 
        (let ([s ($make-string n)])
@@ -1490,30 +1491,30 @@
                       s
                       (f p n s i)))]))))]
       [($fx= n 0) ""]
-      [else (error 'get-string-n "count is negative" n)]))
+      [else (die 'get-string-n "count is negative" n)]))
 
   (define (get-string-n! p s i c) 
     (import (ikarus system $fx) (ikarus system $strings))
     (unless (input-port? p) 
-      (error 'get-string-n! "not an input port" p))
+      (die 'get-string-n! "not an input port" p))
     (unless (textual-port? p) 
-      (error 'get-string-n! "not a textual port" p))
+      (die 'get-string-n! "not a textual port" p))
     (unless (string? s) 
-      (error 'get-string-n! "not a string" s))
+      (die 'get-string-n! "not a string" s))
     (let ([len ($string-length s)])
       (unless (fixnum? i) 
-        (error 'get-string-n! "starting index is not a fixnum" i))
+        (die 'get-string-n! "starting index is not a fixnum" i))
       (when (or ($fx< i 0) ($fx> i len))
-        (error 'get-string-n! 
+        (die 'get-string-n! 
           (format "starting index is out of range 0..~a" len)
           i))
       (unless (fixnum? c) 
-        (error 'get-string-n! "count is not a fixnum" c))
+        (die 'get-string-n! "count is not a fixnum" c))
       (cond
         [($fx> c 0)
          (let ([j (+ i c)])
            (when (> j len)
-             (error 'get-string-n! 
+             (die 'get-string-n! 
                (format "count is out of range 0..~a" (- len i))
                c))
            (let ([x (get-char p)])
@@ -1532,7 +1533,7 @@
                              i
                              (f p s start i c)))])))])))]
         [($fx= c 0) 0]
-        [else (error 'get-string-n! "count is negative" c)])))
+        [else (die 'get-string-n! "count is negative" c)])))
 
   (define (get-line p)
     (import UNSAFE)
@@ -1555,8 +1556,8 @@
     (if (input-port? p)
         (if (textual-port? p)
             (get-it p)
-            (error 'get-line "not a textual port" p))
-        (error 'get-line "not an input port" p)))
+            (die 'get-line "not a textual port" p))
+        (die 'get-line "not an input port" p)))
 
 
   (define (get-string-all p)
@@ -1579,8 +1580,8 @@
     (if (input-port? p)
         (if (textual-port? p)
             (get-it p)
-            (error 'get-string-all "not a textual port" p))
-        (error 'get-string-all "not an input port" p)))
+            (die 'get-string-all "not a textual port" p))
+        (die 'get-string-all "not an input port" p)))
 
 
 
@@ -1598,7 +1599,7 @@
               (bytevector-u8-set! ($port-buffer p) i b) 
               ($set-port-index! p (fx+ i 1))]
              [else
-              (error who "insufficient space on port" p)]))]
+              (die who "insufficient space on port" p)]))]
         [(fx<= b #x7FF) 
          (let ([i ($port-index p)] 
                [j ($port-size p)]
@@ -1657,14 +1658,14 @@
               (bytevector-u8-set! ($port-buffer p) i b)
               ($set-port-index! p (fx+ i 1))]
              [else 
-              (error who "insufficient space in port" p)]))]
+              (die who "insufficient space in port" p)]))]
         [else
          (case (transcoder-error-handling-mode (port-transcoder p))
            [(ignore) (void)]
            [(replace) (put-char p #\?)]
            [(raise) 
             (raise (make-i/o-encoding-error p))]
-           [else (error who "BUG: invalid error handling mode" p)])]))
+           [else (die who "BUG: invalid die handling mode" p)])]))
     (define (put-char-char-mode p c who)
       (flush-output-port p)
       (let ([i ($port-index p)] [j ($port-size p)])
@@ -1673,7 +1674,7 @@
            (string-set! ($port-buffer p) i c)
            ($set-port-index! p (fx+ i 1))]
           [else 
-           (error who "insufficient space in port" p)])))
+           (die who "insufficient space in port" p)])))
     ;;;
     (define write-char
       (case-lambda
@@ -1682,17 +1683,17 @@
     (define (put-char p c) 
       (do-put-char p c 'put-char))
     (define (put-string p str)
-      (unless (string? str) (error 'put-string "not a string" str))
+      (unless (string? str) (die 'put-string "not a string" str))
       (unless (output-port? p)
-        (error 'put-string "not an output port" p))
+        (die 'put-string "not an output port" p))
       (unless (textual-port? p)
-        (error 'put-string "not a textual port" p))
+        (die 'put-string "not a textual port" p))
       (let f ([i 0] [n (string-length str)])
         (unless (fx= i n)
           (do-put-char p (string-ref str i) 'put-string)
           (f (fx+ i 1) n))))
     (define (do-put-char p c who)
-      (unless (char? c) (error who "not a char" c))
+      (unless (char? c) (die who "not a char" c))
       (let ([m ($port-fast-attrs p)])
         (cond
           [(eq? m fast-put-utf8-tag)
@@ -1723,8 +1724,8 @@
                   (put-char-latin-mode p b who)])))]
           [else 
            (if (output-port? p)
-               (error who "not a textual port" p)
-               (error who "not an output port" p))]))))
+               (die who "not a textual port" p)
+               (die who "not an output port" p))]))))
 
   (define newline
     (case-lambda
@@ -1733,11 +1734,11 @@
        (flush-output-port (*the-output-port*))]
       [(p)
        (unless (output-port? p) 
-         (error 'newline "not an output port" p))
+         (die 'newline "not an output port" p))
        (unless (textual-port? p) 
-         (error 'newline "not a textual port" p))
+         (die 'newline "not a textual port" p))
        (when ($port-closed? p) 
-         (error 'newline "port is closed" p))
+         (die 'newline "port is closed" p))
        (put-char p #\newline)
        (flush-output-port p)]))
        
@@ -1753,13 +1754,13 @@
             (when (or (not (fixnum? bytes))
                       (fx< bytes 0)
                       (fx> bytes i))
-              (error who "write! returned an invalid value" bytes))
+              (die who "write! returned an invalid value" bytes))
             (cond
               [(fx= bytes i) 
                (bytevector-u8-set! buf 0 b)
                ($set-port-index! p 1)]
               [(fx= bytes 0) 
-               (error who "could not write bytes to sink")]
+               (die who "could not write bytes to sink")]
               [else
                (let ([i (fx- i bytes)])
                  (bytevector-copy! buf bytes buf 0 i)
@@ -1768,7 +1769,7 @@
     ;;;
     (define (put-u8 p b)
       (define who 'put-u8)
-      (unless (u8? b) (error who "not a u8" b))
+      (unless (u8? b) (die who "not a u8" b))
       (let ([m ($port-fast-attrs p)])
         (cond
           [(eq? m fast-put-byte-tag)
@@ -1781,8 +1782,8 @@
                 (put-u8-byte-mode p b who)]))]
           [else 
            (if (output-port? p)
-               (error who "not a binary port" p)
-               (error who "not an output port" p))]))))
+               (die who "not a binary port" p)
+               (die who "not an output port" p))]))))
 
 
   )
diff --git a/scheme/ikarus.lists.ss b/scheme/ikarus.lists.ss
index 8599760..32445de 100644
--- a/scheme/ikarus.lists.ss
+++ b/scheme/ikarus.lists.ss
@@ -70,11 +70,11 @@
         [(n)
          (if (and (fixnum? n) ($fx>= n 0))
              (f n (void) '())
-             (error 'make-list "not a valid length" n))]
+             (die 'make-list "not a valid length" n))]
         [(n fill)
          (if (and (fixnum? n) ($fx>= n 0))
              (f n fill '())
-             (error 'make-list "not a valid length" n))])))
+             (die 'make-list "not a valid length" n))])))
 
 
   (define length
@@ -85,13 +85,13 @@
                       (if (pair? h)
                           (if (not (eq? h t))
                               (race ($cdr h) ($cdr t) ls ($fx+ n 2))
-                              (error 'length "circular list" ls))
+                              (die 'length "circular list" ls))
                           (if (null? h)
                               ($fx+ n 1)
-                              (error 'length "not a proper list" ls))))
+                              (die 'length "not a proper list" ls))))
                    (if (null? h)
                        n
-                       (error 'length "not a proper list" ls))))])
+                       (die 'length "not a proper list" ls))))])
        (lambda (ls)
          (race ls ls ls 0))))
 
@@ -103,14 +103,14 @@
             [($fxzero? i) 
              (if (pair? ls)
                  ($car ls)
-                 (error 'list-ref "index is out of range" index list))]
+                 (die 'list-ref "index is out of range" index list))]
             [(pair? ls)
              (f ($cdr ls) ($fxsub1 i))]
             [(null? ls) 
-             (error 'list-rec "index is out of range" index list)]
-            [else (error 'list-ref "not a list" list)])))
+             (die 'list-rec "index is out of range" index list)]
+            [else (die 'list-ref "not a list" list)])))
       (unless (and (fixnum? index) ($fx>= index 0))
-        (error 'list-ref "not a valid index" index))
+        (die 'list-ref "not a valid index" index))
       (f list index)))
 
 
@@ -123,10 +123,10 @@
             [(pair? ls)
              (f ($cdr ls) ($fxsub1 i))]
             [(null? ls) 
-             (error 'list-tail "index is out of range" index list)]
-            [else (error 'list-tail "not a list" list)])))
+             (die 'list-tail "index is out of range" index list)]
+            [else (die 'list-tail "not a list" list)])))
       (unless (and (fixnum? index) ($fx>= index 0))
-        (error 'list-tail "not a valid index" index))
+        (die 'list-tail "not a valid index" index))
       (f list index)))
 
   (module (append)
@@ -138,13 +138,13 @@
                    (if (not (eq? h t))
                        (let ([a2 ($car h)])
                          (reverse ($cdr h) ($cdr t) ls (cons a2 (cons a1 ac))))
-                       (error 'append "circular list" ls))
+                       (die 'append "circular list" ls))
                    (if (null? h)
                        (cons a1 ac)
-                       (error 'append "not a proper list" ls))))
+                       (die 'append "not a proper list" ls))))
             (if (null? h)
                 ac 
-                (error 'append "not a proper list" ls)))))
+                (die 'append "not a proper list" ls)))))
     (define revcons
       (lambda (ls ac)
         (cond
@@ -173,13 +173,13 @@
                       (if (pair? h)
                           (if (not (eq? h t))
                               (race ($cdr h) ($cdr t) ls (cons ($car h) ac))
-                              (error 'reverse "circular list" ls))
+                              (die 'reverse "circular list" ls))
                           (if (null? h)
                               ac
-                              (error 'reverse "not a proper list" ls))))
+                              (die 'reverse "not a proper list" ls))))
                    (if (null? h)
                        ac
-                       (error 'reverse "not a proper list" ls))))])
+                       (die 'reverse "not a proper list" ls))))])
        (lambda (x)
          (race x x x '()))))
   
@@ -191,14 +191,14 @@
                        (if (pair? h)
                            (if (not (eq? h t))
                                (race ($cdr h) ($cdr t) ls h)
-                               (error 'last-pair "circular list" ls))
+                               (die 'last-pair "circular list" ls))
                            last))
                     last))])
        (lambda (x)
          (if (pair? x)
              (let ([d (cdr x)])
                (race d d x x))
-             (error 'last-pair "not a pair" x)))))
+             (die 'last-pair "not a pair" x)))))
 
   (define memq
     (letrec ([race
@@ -212,13 +212,13 @@
                                    h
                                    (if (not (eq? h t))
                                        (race ($cdr h) ($cdr t) ls x)
-                                       (error 'memq "circular list" ls)))
+                                       (die 'memq "circular list" ls)))
                                (if (null? h)
                                    '#f
-                                   (error 'memq "not a proper list" ls)))))
+                                   (die 'memq "not a proper list" ls)))))
                      (if (null? h)
                          '#f
-                         (error 'memq "not a proper list" ls))))])
+                         (die 'memq "not a proper list" ls))))])
        (lambda (x ls)
          (race ls ls ls x))))
 
@@ -234,13 +234,13 @@
                                    h
                                    (if (not (eq? h t))
                                        (race ($cdr h) ($cdr t) ls x)
-                                       (error 'memv "circular list" ls)))
+                                       (die 'memv "circular list" ls)))
                                (if (null? h)
                                    '#f
-                                   (error 'memv "not a proper list" ls)))))
+                                   (die 'memv "not a proper list" ls)))))
                      (if (null? h)
                          '#f
-                         (error 'memv "not a proper list" ls))))])
+                         (die 'memv "not a proper list" ls))))])
        (lambda (x ls)
          (race ls ls ls x))))
   
@@ -256,13 +256,13 @@
                                    h
                                    (if (not (eq? h t))
                                        (race ($cdr h) ($cdr t) ls x)
-                                       (error 'member "circular list" ls)))
+                                       (die 'member "circular list" ls)))
                                (if (null? h)
                                    '#f
-                                   (error 'member "not a proper list" ls)))))
+                                   (die 'member "not a proper list" ls)))))
                      (if (null? h)
                          '#f
-                         (error 'member "not a proper list" ls))))])
+                         (die 'member "not a proper list" ls))))])
        (lambda (x ls)
          (race ls ls ls x))))
 
@@ -279,16 +279,16 @@
                                    h
                                    (if (not (eq? h t))
                                        (race ($cdr h) ($cdr t) ls p)
-                                       (error 'memp "circular list" ls)))
+                                       (die 'memp "circular list" ls)))
                                (if (null? h)
                                    '#f
-                                   (error 'memp "not a proper list" ls)))))
+                                   (die 'memp "not a proper list" ls)))))
                      (if (null? h)
                          '#f
-                         (error 'memp "not a proper list" ls))))])
+                         (die 'memp "not a proper list" ls))))])
        (lambda (p ls)
          (unless (procedure? p)
-           (error 'memp "not a procedure" p))
+           (die 'memp "not a procedure" p))
          (race ls ls ls p))))
 
   (define find
@@ -305,16 +305,16 @@
                                        a
                                        (if (not (eq? h t))
                                            (race ($cdr h) ($cdr t) ls p)
-                                           (error 'find "circular list" ls))))
+                                           (die 'find "circular list" ls))))
                                  (if (null? h)
                                      '#f
-                                     (error 'find "not a proper list" ls))))))
+                                     (die 'find "not a proper list" ls))))))
                      (if (null? h)
                          '#f
-                         (error 'find "not a proper list" ls))))])
+                         (die 'find "not a proper list" ls))))])
        (lambda (p ls)
          (unless (procedure? p)
-           (error 'find "not a procedure" p))
+           (die 'find "not a procedure" p))
          (race ls ls ls p))))
 
   (define assq
@@ -332,16 +332,16 @@
                                               (if (eq? ($car a) x)
                                                   a
                                                   (race x ($cdr h) ($cdr t) ls))
-                                              (error 'assq "malformed alist"
+                                              (die 'assq "malformed alist"
                                                      ls)))
-                                       (error 'assq "circular list" ls))
+                                       (die 'assq "circular list" ls))
                                    (if (null? h)
                                        #f
-                                       (error 'assq "not a proper list" ls))))
-                           (error 'assq "malformed alist" ls)))
+                                       (die 'assq "not a proper list" ls))))
+                           (die 'assq "malformed alist" ls)))
                     (if (null? h)
                         #f
-                        (error 'assq "not a proper list" ls))))])
+                        (die 'assq "not a proper list" ls))))])
        (lambda (x ls) 
          (race x ls ls ls))))
 
@@ -361,19 +361,19 @@
                                               (if (p ($car a))
                                                   a
                                                   (race p ($cdr h) ($cdr t) ls))
-                                              (error 'assp "malformed alist"
+                                              (die 'assp "malformed alist"
                                                      ls)))
-                                       (error 'assp "circular list" ls))
+                                       (die 'assp "circular list" ls))
                                    (if (null? h)
                                        #f
-                                       (error 'assp "not a proper list" ls))))
-                           (error 'assp "malformed alist" ls)))
+                                       (die 'assp "not a proper list" ls))))
+                           (die 'assp "malformed alist" ls)))
                     (if (null? h)
                         #f
-                        (error 'assp "not a proper list" ls))))])
+                        (die 'assp "not a proper list" ls))))])
        (lambda (p ls)
          (unless (procedure? p) 
-           (error 'assp "not a procedure" p))
+           (die 'assp "not a procedure" p))
          (race p ls ls ls))))
 
   (define assv
@@ -391,16 +391,16 @@
                                               (if (eqv? ($car a) x)
                                                   a
                                                   (race x ($cdr h) ($cdr t) ls))
-                                              (error 'assv "malformed alist"
+                                              (die 'assv "malformed alist"
                                                      ls)))
-                                       (error 'assv "circular list" ls))
+                                       (die 'assv "circular list" ls))
                                    (if (null? h)
                                        #f
-                                       (error 'assv "not a proper list" ls))))
-                           (error 'assv "malformed alist" ls)))
+                                       (die 'assv "not a proper list" ls))))
+                           (die 'assv "malformed alist" ls)))
                     (if (null? h)
                         #f
-                        (error 'assv "not a proper list" ls))))])
+                        (die 'assv "not a proper list" ls))))])
        (lambda (x ls) 
          (race x ls ls ls))))
 
@@ -419,16 +419,16 @@
                                               (if (equal? ($car a) x)
                                                   a
                                                   (race x ($cdr h) ($cdr t) ls))
-                                              (error 'assoc "malformed alist"
+                                              (die 'assoc "malformed alist"
                                                      ls)))
-                                       (error 'assoc "circular list" ls))
+                                       (die 'assoc "circular list" ls))
                                    (if (null? h)
                                        #f
-                                       (error 'assoc "not a proper list" ls))))
-                           (error 'assoc "malformed alist" ls)))
+                                       (die 'assoc "not a proper list" ls))))
+                           (die 'assoc "malformed alist" ls)))
                     (if (null? h)
                         #f
-                        (error 'assoc "not a proper list" ls))))])
+                        (die 'assoc "not a proper list" ls))))])
        (lambda (x ls) 
          (race x ls ls ls))))
 
@@ -448,23 +448,23 @@
                                           (if (cmp ($car h) x)
                                               (race ($cdr h) ($cdr t) ls x)
                                               (cons ($car h) (race ($cdr h) ($cdr t) ls x)))
-                                          (error 'name "circular list" ls))
+                                          (die 'name "circular list" ls))
                                       (if (null? h)
                                           '()
-                                          (error 'name "not a proper list" ls))))
+                                          (die 'name "not a proper list" ls))))
                                 (let ([a0 ($car h)] [h ($cdr h)])
                                   (if (pair? h)
                                       (if (not (eq? h t))
                                           (if (cmp ($car h) x)
                                               (cons a0 (race ($cdr h) ($cdr t) ls x))
                                               (cons* a0 ($car h) (race ($cdr h) ($cdr t) ls x)))
-                                          (error 'name "circular list" ls))
+                                          (die 'name "circular list" ls))
                                       (if (null? h)
                                           (list a0)
-                                          (error 'name "not a proper list" ls)))))
+                                          (die 'name "not a proper list" ls)))))
                             (if (null? h)
                                 '()
-                                (error 'name "not a proper list" ls))))])
+                                (die 'name "not a proper list" ls))))])
               (lambda (x ls)
                 (check x ls)
                 (race ls ls ls x))))]))
@@ -474,11 +474,11 @@
     (define-remover remp (lambda (elt p) (p elt))
       (lambda (x ls) 
         (unless (procedure? x)
-          (error 'remp "not a procedure" x)))) 
+          (die 'remp "not a procedure" x)))) 
     (define-remover filter (lambda (elt p) (not (p elt)))
       (lambda (x ls) 
         (unless (procedure? x)
-          (error 'filter "not a procedure" x)))))
+          (die 'filter "not a procedure" x)))))
 
 
   (module (map)
@@ -489,27 +489,27 @@
             (let ([h ($cdr h)])
               (if (pair? h)
                   (if (eq? h t)
-                      (error who "circular list")
+                      (die who "circular list")
                       (len ($cdr h) ($cdr t) ($fx+ n 2)))
                   (if (null? h)
                       ($fxadd1 n)
-                      (error who "improper list"))))
+                      (die who "improper list"))))
             (if (null? h)
                 n
-                (error who "improper list")))))
+                (die who "improper list")))))
     (define map1
       (lambda (f a d n)
         (cond
           [(pair? d)
            (if ($fxzero? n)
-               (error who "list was altered!")
+               (die who "list was altered!")
                (cons (f a)
                      (map1 f ($car d) ($cdr d) ($fxsub1 n))))]
           [(null? d)
            (if ($fxzero? n)
                (cons (f a) '())
-               (error who "list was altered"))]
-          [else (error who "list was altered")])))
+               (die who "list was altered"))]
+          [else (die who "list was altered")])))
     (define map2
       (lambda (f a1 a2 d1 d2 n)
         (cond
@@ -517,21 +517,21 @@
            (cond
              [(pair? d2)
               (if ($fxzero? n)
-                  (error who "list was altered")
+                  (die who "list was altered")
                   (cons (f a1 a2) 
                         (map2 f
                               ($car d1) ($car d2)
                               ($cdr d1) ($cdr d2)
                               ($fxsub1 n))))]
-             [else (error who "length mismatch")])]
+             [else (die who "length mismatch")])]
           [(null? d1)
            (cond
              [(null? d2)
               (if ($fxzero? n)
                   (cons (f a1 a2) '())
-                  (error who "list was altered"))]
-             [else (error who "length mismatch")])]
-          [else (error who "list was altered")])))
+                  (die who "list was altered"))]
+             [else (die who "length mismatch")])]
+          [else (die who "list was altered")])))
     (define cars
       (lambda (ls*)
         (cond
@@ -542,7 +542,7 @@
                [(pair? a) 
                 (cons (car a) (cars (cdr ls*)))]
                [else 
-                (error 'map "length mismatch")]))])))
+                (die 'map "length mismatch")]))])))
     (define cdrs
       (lambda (ls*)
         (cond
@@ -553,7 +553,7 @@
                [(pair? a) 
                 (cons (cdr a) (cdrs (cdr ls*)))]
                [else 
-                (error 'map "length mismatch")]))])))
+                (die 'map "length mismatch")]))])))
     (define mapm
       (lambda (f ls ls* n)
         (cond
@@ -561,10 +561,10 @@
            (if (andmap null? ls*)
                (if (fxzero? n)
                    '()
-                   (error 'map "lists were mutated during operation"))
-               (error 'map "length mismatch"))]
+                   (die 'map "lists were mutated during operation"))
+               (die 'map "length mismatch"))]
           [(fxzero? n)
-           (error 'map "lists were mutated during operation")]
+           (die 'map "lists were mutated during operation")]
           [else
            (cons
              (apply f (car ls) (cars ls*))
@@ -573,30 +573,30 @@
        (case-lambda
          [(f ls) 
           (unless (procedure? f)
-            (error who "not a procedure" f))
+            (die who "not a procedure" f))
           (cond
             [(pair? ls)
              (let ([d ($cdr ls)])
                (map1 f ($car ls) d (len d d 0)))]
             [(null? ls) '()]
-            [else (error who "improper list")])]
+            [else (die who "improper list")])]
          [(f ls ls2)
           (unless (procedure? f)
-            (error who "not a procedure" f))
+            (die who "not a procedure" f))
           (cond
             [(pair? ls)
              (if (pair? ls2)
                  (let ([d ($cdr ls)])
                    (map2 f ($car ls) ($car ls2) d ($cdr ls2) (len d d 0)))
-                 (error who "length mismatch"))]
+                 (die who "length mismatch"))]
             [(null? ls)
              (if (null? ls2)
                  '()
-                 (error who "length mismatch"))]
-            [else (error who "not a list")])]
+                 (die who "length mismatch"))]
+            [else (die who "not a list")])]
          [(f ls . ls*)
           (unless (procedure? f)
-            (error who "not a procedure" f))
+            (die who "not a procedure" f))
           (cond
             [(pair? ls)
              (let ([n (len ls ls 0)])
@@ -604,7 +604,7 @@
             [(null? ls)
              (if (andmap null? ls*)
                  '()
-                 (error who "length mismatch"))])])))
+                 (die who "length mismatch"))])])))
 
   (module (for-each)
     (define who 'for-each)
@@ -614,28 +614,28 @@
             (let ([h ($cdr h)])
               (if (pair? h)
                   (if (eq? h t)
-                      (error who "circular list")
+                      (die who "circular list")
                       (len ($cdr h) ($cdr t) ($fx+ n 2)))
                   (if (null? h)
                       ($fxadd1 n)
-                      (error who "improper list"))))
+                      (die who "improper list"))))
             (if (null? h)
                 n
-                (error who "improper list")))))
+                (die who "improper list")))))
     (define for-each1
       (lambda (f a d n)
         (cond
           [(pair? d)
            (if ($fxzero? n)
-               (error who "list was altered!")
+               (die who "list was altered!")
                (begin 
                  (f a)
                  (for-each1 f ($car d) ($cdr d) ($fxsub1 n))))]
           [(null? d)
            (if ($fxzero? n)
                (f a)
-               (error who "list was altered"))]
-          [else (error who "list was altered")])))
+               (die who "list was altered"))]
+          [else (die who "list was altered")])))
     (define for-each2
       (lambda (f a1 a2 d1 d2 n)
         (cond
@@ -643,67 +643,67 @@
            (cond
              [(pair? d2)
               (if ($fxzero? n)
-                  (error who "list was altered")
+                  (die who "list was altered")
                   (begin
                     (f a1 a2) 
                     (for-each2 f
                       ($car d1) ($car d2)
                       ($cdr d1) ($cdr d2)
                       ($fxsub1 n))))]
-             [else (error who "length mismatch")])]
+             [else (die who "length mismatch")])]
           [(null? d1)
            (cond
              [(null? d2)
               (if ($fxzero? n)
                   (f a1 a2)
-                  (error who "list was altered"))]
-             [else (error who "length mismatch")])]
-          [else (error who "list was altered")])))
+                  (die who "list was altered"))]
+             [else (die who "length mismatch")])]
+          [else (die who "list was altered")])))
     (define for-each
        (case-lambda
          [(f ls)
           (unless (procedure? f)
-            (error who "not a procedure" f))
+            (die who "not a procedure" f))
           (cond
             [(pair? ls)
              (let ([d ($cdr ls)])
                (for-each1 f ($car ls) d (len d d 0)))]
             [(null? ls) (void)]
-            [else (error who "improper list")])]
+            [else (die who "improper list")])]
          [(f ls ls2)
           (unless (procedure? f)
-            (error who "not a procedure" f))
+            (die who "not a procedure" f))
           (cond
             [(pair? ls)
              (if (pair? ls2)
                  (let ([d ($cdr ls)])
                    (for-each2 f
                       ($car ls) ($car ls2) d ($cdr ls2) (len d d 0)))
-                 (error who "length mismatch"))]
+                 (die who "length mismatch"))]
             [(null? ls)
              (if (null? ls2)
                  (void)
-                 (error who "length mismatch"))]
-            [else (error who "not a list")])]
+                 (die who "length mismatch"))]
+            [else (die who "not a list")])]
          [(f ls . ls*)
           (unless (procedure? f) 
-            (error 'for-each "not a procedure" f))
+            (die 'for-each "not a procedure" f))
           (unless (list? ls) 
-            (error 'for-each "not a list" ls))
+            (die 'for-each "not a list" ls))
           (let ([n (length ls)])
             (for-each 
               (lambda (x) 
                 (unless (and (list? x) (= (length x) n))
-                  (error 'for-each "not a list" x)))
+                  (die 'for-each "not a list" x)))
               ls*)
             (let loop ([n (length ls)] [ls ls] [ls* ls*])
               (cond
                 [($fx= n 0) 
                  (unless (and (null? ls) (andmap null? ls*))
-                   (error 'for-each "list modified" f))]
+                   (die 'for-each "list modified" f))]
                 [else
                  (unless (and (pair? ls) (andmap pair? ls*))
-                   (error 'for-each "list modified" f))
+                   (die 'for-each "list modified" f))
                  (apply f (car ls) (map car ls*))
                  (loop (fx- n 1) (cdr ls) (map cdr ls*))])))])))
 
@@ -715,27 +715,27 @@
             (let ([h ($cdr h)])
               (if (pair? h)
                   (if (eq? h t)
-                      (error who "circular list")
+                      (die who "circular list")
                       (len ($cdr h) ($cdr t) ($fx+ n 2)))
                   (if (null? h)
                       ($fxadd1 n)
-                      (error who "improper list"))))
+                      (die who "improper list"))))
             (if (null? h)
                 n
-                (error who "improper list")))))
+                (die who "improper list")))))
     (define andmap1
       (lambda (f a d n)
         (cond
           [(pair? d)
            (if ($fxzero? n)
-               (error who "list was altered!")
+               (die who "list was altered!")
                (and (f a)
                     (andmap1 f ($car d) ($cdr d) ($fxsub1 n))))]
           [(null? d)
            (if ($fxzero? n)
                (f a)
-               (error who "list was altered"))]
-          [else (error who "list was altered")])))
+               (die who "list was altered"))]
+          [else (die who "list was altered")])))
     (define andmap2
       (lambda (f a1 a2 d1 d2 n)
         (cond
@@ -743,52 +743,52 @@
            (cond
              [(pair? d2)
               (if ($fxzero? n)
-                  (error who "list was altered")
+                  (die who "list was altered")
                   (and
                     (f a1 a2) 
                     (andmap2 f
                       ($car d1) ($car d2)
                       ($cdr d1) ($cdr d2)
                       ($fxsub1 n))))]
-             [else (error who "length mismatch")])]
+             [else (die who "length mismatch")])]
           [(null? d1)
            (cond
              [(null? d2)
               (if ($fxzero? n)
                   (f a1 a2)
-                  (error who "list was altered"))]
-             [else (error who "length mismatch")])]
-          [else (error who "list was altered")])))
+                  (die who "list was altered"))]
+             [else (die who "length mismatch")])]
+          [else (die who "list was altered")])))
     (define andmap
        (case-lambda
          [(f ls)
           (unless (procedure? f)
-            (error who "not a procedure" f))
+            (die who "not a procedure" f))
           (cond
             [(pair? ls)
              (let ([d ($cdr ls)])
                (andmap1 f ($car ls) d (len d d 0)))]
             [(null? ls) #t]
-            [else (error who "improper list")])]
+            [else (die who "improper list")])]
          [(f ls ls2)
           (unless (procedure? f)
-            (error who "not a procedure" f))
+            (die who "not a procedure" f))
           (cond
             [(pair? ls)
              (if (pair? ls2)
                  (let ([d ($cdr ls)])
                    (andmap2 f
                       ($car ls) ($car ls2) d ($cdr ls2) (len d d 0)))
-                 (error who "length mismatch"))]
+                 (die who "length mismatch"))]
             [(null? ls)
              (if (null? ls2)
                  #t
-                 (error who "length mismatch"))]
-            [else (error who "not a list")])]
+                 (die who "length mismatch"))]
+            [else (die who "not a list")])]
          [(f ls . ls*)
           (unless (procedure? f) 
-            (error who "not a procedure" f))
-          (error who "vararg not yet supported")])))
+            (die who "not a procedure" f))
+          (die who "vararg not yet supported")])))
 
 
 
@@ -801,39 +801,39 @@
             (let ([h ($cdr h)])
               (if (pair? h)
                   (if (eq? h t)
-                      (error who "circular list")
+                      (die who "circular list")
                       (len ($cdr h) ($cdr t) ($fx+ n 2)))
                   (if (null? h)
                       ($fxadd1 n)
-                      (error who "improper list"))))
+                      (die who "improper list"))))
             (if (null? h)
                 n
-                (error who "improper list")))))
+                (die who "improper list")))))
     (define ormap1
       (lambda (f a d n)
         (cond
           [(pair? d)
            (if ($fxzero? n)
-               (error who "list was altered!")
+               (die who "list was altered!")
                (or (f a)
                    (ormap1 f ($car d) ($cdr d) ($fxsub1 n))))]
           [(null? d)
            (if ($fxzero? n)
                (f a)
-               (error who "list was altered"))]
-          [else (error who "list was altered")])))
+               (die who "list was altered"))]
+          [else (die who "list was altered")])))
     (define ormap
        (case-lambda
          [(f ls)
           (unless (procedure? f)
-            (error who "not a procedure" f))
+            (die who "not a procedure" f))
           (cond
             [(pair? ls)
              (let ([d ($cdr ls)])
                (ormap1 f ($car ls) d (len d d 0)))]
             [(null? ls) #f]
-            [else (error who "improper list")])]
-         [_ (error who "vararg not supported yet")])))
+            [else (die who "improper list")])]
+         [_ (die who "vararg not supported yet")])))
 
 
 
@@ -844,7 +844,7 @@
                      (let ([a0 ($car h)] [h ($cdr h)])
                         (if (pair? h)
                             (if (eq? h t)
-                                (error 'partition "circular list" ls)
+                                (die 'partition "circular list" ls)
                                 (let ([a1 ($car h)])
                                   (let-values ([(a* b*) (race ($cdr h) ($cdr t) ls p)])
                                     (if (p a0) 
@@ -858,13 +858,13 @@
                                 (if (p a0)
                                     (values (list a0) '())
                                     (values '() (list a0)))
-                                (error 'parititon "not a proper list" ls))))
+                                (die 'parititon "not a proper list" ls))))
                      (if (null? h)
                          (values '() '())
-                         (error 'parition "not a proper list" ls))))])
+                         (die 'parition "not a proper list" ls))))])
        (lambda (p ls)
          (unless (procedure? p) 
-           (error 'partition "not a procedure" p))
+           (die 'partition "not a procedure" p))
          (race ls ls ls p))))
 
 
@@ -878,10 +878,10 @@
            (or (null? ls) (and (null? (car ls)) (null*? (cdr ls)))))
          (define (err* ls*)
            (if (null? ls*) 
-               (error who "length mismatch")
+               (die who "length mismatch")
                (if (list? (car ls*))
                    (err* (cdr ls*))
-                   (error who "not a proper list" (car ls*)))))
+                   (die who "not a proper list" (car ls*)))))
          (define (cars+cdrs ls ls*)
            (cond
              [(null? ls) (values '() '())]
@@ -891,23 +891,23 @@
                     (let-values ([(cars cdrs) (cars+cdrs (cdr ls) (cdr ls*))])
                       (values (cons (car a) cars) (cons (cdr a) cdrs)))
                     (if (list? (car ls*)) 
-                        (error who "length mismatch")
-                        (error who "not a proper list" (car ls*)))))]))
+                        (die who "length mismatch")
+                        (die who "not a proper list" (car ls*)))))]))
          (define (loop1 f a h t ls)
            (if (pair? h)
                (let ([b (car h)] [h (cdr h)])
                  (combine (f a)
                    (if (pair? h)
                        (if (eq? h t)
-                           (error who "circular" ls)
+                           (die who "circular" ls)
                            (let ([c (car h)] [h (cdr h)])
                              (combine (f b) (loop1 f c h (cdr t) ls))))
                        (if (null? h) 
                            (f b)
-                           (combine (f b) (error who "not a proper list" ls))))))
+                           (combine (f b) (die who "not a proper list" ls))))))
                (if (null? h)
                    (f a)
-                   (combine (f a) (error who "not a proper list" ls)))))
+                   (combine (f a) (die who "not a proper list" ls)))))
          (define (loopn f a a* h h* t ls ls*)
            (if (pair? h)
                (let-values ([(b* h*) (cars+cdrs h* ls*)])
@@ -915,7 +915,7 @@
                    (combine (apply f a a*)
                      (if (pair? h)
                          (if (eq? h t)
-                             (error who "circular" ls)
+                             (die who "circular" ls)
                              (let-values ([(c* h*) (cars+cdrs h* ls*)])
                                (let ([c (car h)] [h (cdr h)])
                                  (combine (apply f b b*) 
@@ -930,15 +930,15 @@
            (case-lambda
              [(f ls)
               (unless (procedure? f) 
-                (error who "not a procedure" f))
+                (die who "not a procedure" f))
               (if (pair? ls)
                   (loop1 f (car ls) (cdr ls) (cdr ls) ls)
                   (if (null? ls)
                       (combine)
-                      (error who "not a list" ls)))]
+                      (die who "not a list" ls)))]
              [(f ls . ls*)
               (unless (procedure? f) 
-                (error who "not a procedure" f))
+                (die who "not a procedure" f))
               (if (pair? ls)
                   (let-values ([(cars cdrs) (cars+cdrs ls* ls*)])
                     (loopn f (car ls) cars (cdr ls) cdrs (cdr ls) ls ls*))
@@ -955,10 +955,10 @@
       (or (null? ls) (and (null? (car ls)) (null*? (cdr ls)))))
     (define (err* ls*)
       (if (null? ls*)
-          (error who "length mismatch")
+          (die who "length mismatch")
           (if (list? (car ls*))
               (err* (cdr ls*))
-              (error who "not a proper list" (car ls*)))))
+              (die who "not a proper list" (car ls*)))))
     (define (cars+cdrs ls ls*)
       (cond
         [(null? ls) (values '() '())]
@@ -968,29 +968,29 @@
                (let-values ([(cars cdrs) (cars+cdrs (cdr ls) (cdr ls*))])
                  (values (cons (car a) cars) (cons (cdr a) cdrs)))
                (if (list? (car ls*)) 
-                   (error who "length mismatch")
-                   (error who "not a proper list" (car ls*)))))]))
+                   (die who "length mismatch")
+                   (die who "not a proper list" (car ls*)))))]))
      (define (loop1 f nil h t ls)
        (if (pair? h)
            (let ([a (car h)] [h (cdr h)])
              (if (pair? h) 
                  (if (eq? h t)
-                     (error who "circular" ls)
+                     (die who "circular" ls)
                      (let ([b (car h)] [h (cdr h)] [t (cdr t)])
                        (loop1 f (f (f nil a) b) h t ls)))
                  (if (null? h)
                      (f nil a)
-                     (error who "not a proper list" ls))))
+                     (die who "not a proper list" ls))))
            (if (null? h)
                nil
-               (error who "not a proper list" ls))))
+               (die who "not a proper list" ls))))
     (define (loopn f nil h h* t ls ls*)
       (if (pair? h)
           (let-values ([(a* h*) (cars+cdrs h* ls*)])
             (let ([a (car h)] [h (cdr h)])
               (if (pair? h) 
                   (if (eq? h t)
-                      (error who "circular" ls)
+                      (die who "circular" ls)
                       (let-values ([(b* h*) (cars+cdrs h* ls*)])
                         (let ([b (car h)] [h (cdr h)] [t (cdr t)])
                           (loopn f 
@@ -1006,11 +1006,11 @@
       (case-lambda
         [(f nil ls) 
          (unless (procedure? f)
-           (error who "not a procedure" f))
+           (die who "not a procedure" f))
          (loop1 f nil ls ls ls)]
         [(f nil ls . ls*) 
          (unless (procedure? f)
-           (error who "not a procedure" f))
+           (die who "not a procedure" f))
          (loopn f nil ls ls* ls ls ls*)])))
   
   (module (fold-right)
@@ -1019,10 +1019,10 @@
       (or (null? ls) (and (null? (car ls)) (null*? (cdr ls)))))
     (define (err* ls*)
       (if (null? ls*)
-          (error who "length mismatch")
+          (die who "length mismatch")
           (if (list? (car ls*))
               (err* (cdr ls*))
-              (error who "not a proper list" (car ls*)))))
+              (die who "not a proper list" (car ls*)))))
     (define (cars+cdrs ls ls*)
       (cond
         [(null? ls) (values '() '())]
@@ -1032,29 +1032,29 @@
                (let-values ([(cars cdrs) (cars+cdrs (cdr ls) (cdr ls*))])
                  (values (cons (car a) cars) (cons (cdr a) cdrs)))
                (if (list? (car ls*)) 
-                   (error who "length mismatch")
-                   (error who "not a proper list" (car ls*)))))]))
+                   (die who "length mismatch")
+                   (die who "not a proper list" (car ls*)))))]))
      (define (loop1 f nil h t ls)
        (if (pair? h)
            (let ([a (car h)] [h (cdr h)])
              (if (pair? h) 
                  (if (eq? h t)
-                     (error who "circular" ls)
+                     (die who "circular" ls)
                      (let ([b (car h)] [h (cdr h)] [t (cdr t)])
                        (f a (f b (loop1 f nil h t ls)))))
                  (if (null? h)
                      (f a nil)
-                     (error who "not a proper list" ls))))
+                     (die who "not a proper list" ls))))
            (if (null? h)
                nil
-               (error who "not a proper list" ls))))
+               (die who "not a proper list" ls))))
     (define (loopn f nil h h* t ls ls*)
       (if (pair? h)
           (let-values ([(a* h*) (cars+cdrs h* ls*)])
             (let ([a (car h)] [h (cdr h)])
               (if (pair? h) 
                   (if (eq? h t)
-                      (error who "circular" ls)
+                      (die who "circular" ls)
                       (let-values ([(b* h*) (cars+cdrs h* ls*)])
                         (let ([b (car h)] [h (cdr h)] [t (cdr t)])
                           (apply f a
@@ -1073,11 +1073,11 @@
       (case-lambda
         [(f nil ls) 
          (unless (procedure? f)
-           (error who "not a procedure" f))
+           (die who "not a procedure" f))
          (loop1 f nil ls ls ls)]
         [(f nil ls . ls*) 
          (unless (procedure? f)
-           (error who "not a procedure" f))
+           (die who "not a procedure" f))
          (loopn f nil ls ls* ls ls ls*)]
         )))
 
diff --git a/scheme/ikarus.load.ss b/scheme/ikarus.load.ss
index 1c74876..3d24e36 100644
--- a/scheme/ikarus.load.ss
+++ b/scheme/ikarus.load.ss
@@ -35,9 +35,9 @@
       [(x) (load x load-handler)]
       [(x eval-proc)
        (unless (string? x)
-         (error 'load "not a string" x))
+         (die 'load "not a string" x))
        (unless (procedure? eval-proc)
-         (error 'load "not a procedure" eval-proc))
+         (die 'load "not a procedure" eval-proc))
        (let ([p (open-input-file x)])
          (let ([x (read-initial p)])
            (unless (eof-object? x)
diff --git a/scheme/ikarus.main.ss b/scheme/ikarus.main.ss
index e1d0436..32da13a 100644
--- a/scheme/ikarus.main.ss
+++ b/scheme/ikarus.main.ss
@@ -77,14 +77,14 @@
                      (let ([d (cdr args)])
                        (cond
                          [(null? d)
-                          (error 'ikarus "--script requires a script name")]
+                          (die 'ikarus "--script requires a script name")]
                          [else
                           (values '() (car d) 'script (cdr d))]))]
                     [(string=? (car args) "--r6rs-script")
                      (let ([d (cdr args)])
                        (cond
                          [(null? d)
-                          (error 'ikarus "--r6rs-script requires a script name")]
+                          (die 'ikarus "--r6rs-script requires a script name")]
                          [else
                           (values '() (car d) 'r6rs-script (cdr d))]))]
                     [else
diff --git a/scheme/ikarus.numerics.ss b/scheme/ikarus.numerics.ss
index d50c4a3..c9422f0 100644
--- a/scheme/ikarus.numerics.ss
+++ b/scheme/ikarus.numerics.ss
@@ -43,7 +43,7 @@
   
   (define (flonum-bytes f)
     (unless (flonum? f) 
-      (error 'flonum-bytes "not a flonum" f))
+      (die 'flonum-bytes "not a flonum" f))
     (values 
       ($flonum-u8-ref f 0)
       ($flonum-u8-ref f 1)
@@ -55,7 +55,7 @@
       ($flonum-u8-ref f 7)))
   (define (flonum-parts x)
     (unless (flonum? x) 
-      (error 'flonum-parts "not a flonum" x))
+      (die 'flonum-parts "not a flonum" x))
     (let-values ([(b0 b1 b2 b3 b4 b5 b6 b7) (flonum-bytes x)])
       (values 
         (zero? (fxlogand b0 128)) 
@@ -108,7 +108,7 @@
   (define (flround x)
     (if (flonum? x)
         ($flround x)
-        (error 'flround "not a flonum" x)))
+        (die 'flround "not a flonum" x)))
 
   (module ($flonum->integer $flonum->exact)
     (define ($flonum-signed-mantissa x)
@@ -183,7 +183,7 @@
 
   (define (flnumerator x) 
     (unless (flonum? x) 
-      (error 'flnumerator "not a flonum" x))
+      (die 'flnumerator "not a flonum" x))
     (cond
       [($flonum-integer? x) x]
       [($flonum-rational? x) 
@@ -192,7 +192,7 @@
 
   (define (fldenominator x) 
     (unless (flonum? x) 
-      (error 'fldenominator "not a flonum" x))
+      (die 'fldenominator "not a flonum" x))
     (cond
       [($flonum-integer? x) 1.0]
       [($flonum-rational? x) 
@@ -203,49 +203,49 @@
   (define (fleven? x)
     ;;; FIXME: optimize
     (unless (flonum? x) 
-      (error 'fleven? "not a flonum" x))
+      (die 'fleven? "not a flonum" x))
     (let ([v ($flonum->exact x)])
       (cond
         [(fixnum? v) ($fx= ($fxlogand v 1) 0)]
         [(bignum? v) 
          (foreign-call "ikrt_even_bn" v)]
-        [else (error 'fleven? "not an integer flonum" x)])))
+        [else (die 'fleven? "not an integer flonum" x)])))
 
   (define (flodd? x)
     (unless (flonum? x) 
-      (error 'flodd? "not a flonum" x))
+      (die 'flodd? "not a flonum" x))
     ;;; FIXME: optimize
     (let ([v ($flonum->exact x)])
       (cond
         [(fixnum? v) ($fx= ($fxlogand v 1) 1)]
         [(bignum? v) 
          (not (foreign-call "ikrt_even_bn" v))]
-        [else (error 'flodd? "not an integer flonum" x)])))
+        [else (die 'flodd? "not an integer flonum" x)])))
 
   (define (flinteger? x)
     (if (flonum? x)
         ($flonum-integer? x)
-        (error 'flinteger? "not a flonum" x)))
+        (die 'flinteger? "not a flonum" x)))
 
   (define (flinfinite? x) 
     (if (flonum? x) 
         (let ([be (fxlogand ($flonum-sbe x) (sub1 (fxsll 1 11)))])
           (and (fx= be 2047)  ;;; nans and infs
                ($zero-m? x)))
-        (error 'flinfinite? "not a flonum" x)))
+        (die 'flinfinite? "not a flonum" x)))
 
   (define (flnan? x) 
     (if (flonum? x) 
         (let ([be (fxlogand ($flonum-sbe x) (sub1 (fxsll 1 11)))])
           (and (fx= be 2047)  ;;; nans and infs
                (not ($zero-m? x))))
-        (error 'flnan? "not a flonum" x)))
+        (die 'flnan? "not a flonum" x)))
 
   (define (flfinite? x) 
     (if (flonum? x) 
         (let ([be (fxlogand ($flonum-sbe x) (sub1 (fxsll 1 11)))])
           (not (fx= be 2047)))
-        (error 'flfinite? "not a flonum" x)))
+        (die 'flfinite? "not a flonum" x)))
   
   (define ($flzero? x)
     (let ([be (fxlogand ($flonum-sbe x) (sub1 (fxsll 1 11)))])
@@ -271,67 +271,67 @@
     (cond
       [(flonum? x)
        (or ($flonum->exact x)
-           (error 'inexact->exact "no real value" x))]
+           (die 'inexact->exact "no real value" x))]
       [(or (fixnum? x) (ratnum? x) (bignum? x)) x]
       [else
-       (error 'inexact->exact "not an inexact number" x)]))
+       (die 'inexact->exact "not an inexact number" x)]))
 
   (define (exact x)
     (cond
       [(flonum? x)
        (or ($flonum->exact x)
-           (error 'exact "no real value" x))]
+           (die 'exact "no real value" x))]
       [(or (fixnum? x) (ratnum? x) (bignum? x)) x]
       [else
-       (error 'exact "not an inexact number" x)]))
+       (die 'exact "not an inexact number" x)]))
 
 
   (define (flpositive? x)
     (if (flonum? x) 
         ($fl> x 0.0)
-        (error 'flpositive? "not a flonum" x)))
+        (die 'flpositive? "not a flonum" x)))
   
   (define (flabs x)
     (if (flonum? x) 
         (if ($fx> ($flonum-u8-ref x 0) 127)
             ($fl* x -1.0)
             x)
-        (error 'flabs "not a flonum" x)))
+        (die 'flabs "not a flonum" x)))
 
   (define (fixnum->flonum x)
     (if (fixnum? x) 
         ($fixnum->flonum x)
-        (error 'fixnum->flonum "not a fixnum")))
+        (die 'fixnum->flonum "not a fixnum")))
 
   (define (flsin x)
     (if (flonum? x) 
         (foreign-call "ikrt_fl_sin" x)
-        (error 'flsin "not a flonum" x)))
+        (die 'flsin "not a flonum" x)))
 
   (define (flcos x)
     (if (flonum? x) 
         (foreign-call "ikrt_fl_cos" x)
-        (error 'flcos "not a flonum" x)))
+        (die 'flcos "not a flonum" x)))
 
   (define (fltan x)
     (if (flonum? x) 
         (foreign-call "ikrt_fl_tan" x)
-        (error 'fltan "not a flonum" x)))
+        (die 'fltan "not a flonum" x)))
 
   (define (flasin x)
     (if (flonum? x) 
         (foreign-call "ikrt_fl_asin" x)
-        (error 'flasin "not a flonum" x)))
+        (die 'flasin "not a flonum" x)))
 
   (define (flacos x)
     (if (flonum? x) 
         (foreign-call "ikrt_fl_acos" x)
-        (error 'flacos "not a flonum" x)))
+        (die 'flacos "not a flonum" x)))
 
   (define (flatan x)
     (if (flonum? x) 
         (foreign-call "ikrt_fl_atan" x)
-        (error 'flatan "not a flonum" x)))
+        (die 'flatan "not a flonum" x)))
 
 
   (define (flfloor x)
@@ -347,7 +347,7 @@
            [(ratnum? e)
             (exact->inexact (ratnum-floor e))] 
            [else x]))]
-      [else (error 'flfloor "not a flonum" x)]))
+      [else (die 'flfloor "not a flonum" x)]))
 
   (define (flceiling x)
     (cond
@@ -358,19 +358,19 @@
            [(ratnum? e)
             (exact->inexact (ceiling e))] 
            [else x]))]
-      [else (error 'flceiling "not a flonum" x)]))
+      [else (die 'flceiling "not a flonum" x)]))
 
   (define (flexp x)
     (if (flonum? x) 
         (foreign-call "ikrt_fl_exp" x ($make-flonum))
-        (error 'flexp "not a flonum" x)))
+        (die 'flexp "not a flonum" x)))
 
   (define (fllog x)
     (if (flonum? x)
         (if ($fl>= x 0.0) 
             (foreign-call "ikrt_fl_log" x)
-            (error 'fllog "argument should not be negative" x))
-        (error 'fllog "not a flonum" x)))
+            (die 'fllog "argument should not be negative" x))
+        (die 'fllog "not a flonum" x)))
 
   (define (flexpt x y)
     (if (flonum? x)
@@ -382,8 +382,8 @@
                 [(bignum? y^) (inexact (expt x y^))]
                 [else
                  (foreign-call "ikrt_flfl_expt" x y ($make-flonum))]))
-            (error 'flexpt "not a flonum" y))
-        (error 'fllog "not a flonum" x)))
+            (die 'flexpt "not a flonum" y))
+        (die 'fllog "not a flonum" x)))
 
 
   )
@@ -558,7 +558,7 @@
             (fxlogor (fxsll b2 4) (fxsra b1 4))
             (fxlogor (fxsll b1 4) (fxsra b0 4))
             (fxsra b0 3))]
-        [else (error '$float/aux "BUG: invalid b7" b7)]))
+        [else (die '$float/aux "BUG: invalid b7" b7)]))
     (define (bignum->flonum x)
       (define (bignum/4->flonum x) 
         ($flonum/aux ($bignum-positive? x) -24 
@@ -582,7 +582,7 @@
               (if (fx= b6 0)
                   (if (fx= b5 0)
                       (if (fx= b4 0)
-                          (error 'bignum8->flonum "malformed bignum")
+                          (die 'bignum8->flonum "malformed bignum")
                           ($flonum/aux pos? -16 b4 b3 b2 b1 b0 0 0 0))
                       ($flonum/aux pos? -8 b5 b4 b3 b2 b1 b0 0 0))
                   ($flonum/aux pos? 0 b6 b5 b4 b3 b2 b1 b0 0))
@@ -607,14 +607,14 @@
                       (if (fx= bn 0)
                           (let* ([bytes (fxsub1 bytes)] [bn ($bignum-byte-ref x bytes)])
                             (if (fx= bn 0)
-                                (error 'bignum/n->flonum "malformed bignum")
+                                (die 'bignum/n->flonum "malformed bignum")
                                 (aux x bn bytes)))
                           (aux x bn bytes)))
                     (aux x bn bytes)))
               (aux x bn bytes))))
               
       (unless (bignum? x)
-        (error 'bignum->flonum "not a bignum" x))
+        (die 'bignum->flonum "not a bignum" x))
       (let ([bytes ($bignum-size x)])
         (case bytes
           [(4)  (bignum/4->flonum x)]
@@ -666,7 +666,7 @@
               (+ (* x ($ratnum-d y)) ($ratnum-n y))
               ($ratnum-d y))]
            [else 
-            (error '+ "not a number" y)])]
+            (die '+ "not a number" y)])]
         [(bignum? x)
          (cond
            [(fixnum? y)
@@ -680,7 +680,7 @@
               (+ (* x ($ratnum-d y)) ($ratnum-n y))
               ($ratnum-d y))] 
            [else 
-            (error '+ "not a number" y)])]
+            (die '+ "not a number" y)])]
         [(flonum? x)
          (cond
            [(fixnum? y)
@@ -692,7 +692,7 @@
            [(ratnum? y)
             ($fl+ x (ratnum->flonum y))]
            [else 
-            (error '+ "not a number" y)])]
+            (die '+ "not a number" y)])]
         [(ratnum? x)
          (cond
            [(or (fixnum? y) (bignum? y))
@@ -707,8 +707,8 @@
               ;;; FIXME: inefficient
               (/ (+ (* n0 d1) (* n1 d0)) (* d0 d1)))]
            [else 
-            (error '+ "not a number" y)])] 
-        [else (error '+ "not a number" x)])))
+            (die '+ "not a number" y)])] 
+        [else (die '+ "not a number" x)])))
 
   (define binary-bitwise-and
     (lambda (x y)
@@ -719,7 +719,7 @@
            [(bignum? y)
             (foreign-call "ikrt_fxbnlogand" x y)]
            [else 
-            (error 'bitwise-and "not an exact integer" y)])]
+            (die 'bitwise-and "not an exact integer" y)])]
         [(bignum? x)
          (cond
            [(fixnum? y)
@@ -727,8 +727,8 @@
            [(bignum? y) 
             (foreign-call "ikrt_bnbnlogand" x y)]
            [else
-            (error 'bitwise-and "not an exact integer" y)])]
-        [else (error 'bitwise-and "not an exact integer" x)])))
+            (die 'bitwise-and "not an exact integer" y)])]
+        [else (die 'bitwise-and "not an exact integer" x)])))
 
 
   (define binary-
@@ -748,7 +748,7 @@
             (let ([n ($ratnum-n y)] [d ($ratnum-d y)])
               (binary/ (binary- (binary* d x) n) d))]
            [else 
-            (error '- "not a number" y)])]
+            (die '- "not a number" y)])]
         [(bignum? x)
          (cond
            [(fixnum? y)
@@ -761,7 +761,7 @@
             (let ([n ($ratnum-n y)] [d ($ratnum-d y)])
               (binary/ (binary- (binary* d x) n) d))]
            [else 
-            (error '- "not a number" y)])]
+            (die '- "not a number" y)])]
         [(flonum? x)
          (cond
            [(fixnum? y)
@@ -774,7 +774,7 @@
             (let ([n ($ratnum-n y)] [d ($ratnum-d y)])
               (binary/ (binary- (binary* d x) n) d))]
            [else
-            (error '- "not a number" y)])]
+            (die '- "not a number" y)])]
         [(ratnum? x)
          (let ([nx ($ratnum-n x)] [dx ($ratnum-d x)])
            (cond
@@ -785,8 +785,8 @@
                 (binary/ (binary- (binary* nx dy) (binary* ny dx))
                          (binary* dx dy)))]
              [else
-              (error '- "not a number" y)]))]
-        [else (error '- "not a number" x)])))
+              (die '- "not a number" y)]))]
+        [else (die '- "not a number" x)])))
 
   (define binary*
     (lambda (x y)
@@ -802,7 +802,7 @@
            [(ratnum? y) 
             (binary/ (binary* x ($ratnum-n y)) ($ratnum-d y))]
            [else 
-            (error '* "not a number" y)])]
+            (die '* "not a number" y)])]
         [(bignum? x)
          (cond
            [(fixnum? y)
@@ -814,7 +814,7 @@
            [(ratnum? y) 
             (binary/ (binary* x ($ratnum-n y)) ($ratnum-d y))]
            [else 
-            (error '* "not a number" y)])]
+            (die '* "not a number" y)])]
         [(flonum? x)
          (cond
            [(fixnum? y)
@@ -826,13 +826,13 @@
            [(ratnum? y) 
             (binary/ (binary* x ($ratnum-n y)) ($ratnum-d y))]
            [else
-            (error '* "not a number" y)])]
+            (die '* "not a number" y)])]
         [(ratnum? x) 
          (if (ratnum? y) 
              (binary/ (binary* ($ratnum-n x) ($ratnum-n y))
                       (binary* ($ratnum-d x) ($ratnum-d y)))
              (binary* y x))]
-        [else (error '* "not a number" x)])))
+        [else (die '* "not a number" x)])))
 
   (define +
     (case-lambda
@@ -842,7 +842,7 @@
        (cond
          [(fixnum? a) a]
          [(bignum? a) a]
-         [else (error '+ "not a number" a)])]
+         [else (die '+ "not a number" a)])]
       [() 0]
       [(a b c d . e*)
        (let f ([ac (binary+ (binary+ (binary+ a b) c) d)]
@@ -859,7 +859,7 @@
        (cond
          [(fixnum? a) a]
          [(bignum? a) a]
-         [else (error 'bitwise-and "not a number" a)])]
+         [else (die 'bitwise-and "not a number" a)])]
       [() -1]
       [(a b c d . e*)
        (let f ([ac (binary-bitwise-and a
@@ -874,7 +874,7 @@
     (cond
       [(fixnum? x) ($fxlognot x)]
       [(bignum? x) (foreign-call "ikrt_bnlognot" x)]
-      [else (error 'bitwise-not "invalid argument" x)]))
+      [else (die 'bitwise-not "invalid argument" x)]))
 
   (define -
     (case-lambda
@@ -896,7 +896,7 @@
        (cond
          [(fixnum? a) a]
          [(bignum? a) a]
-         [else (error '* "not a number" a)])]
+         [else (die '* "not a number" a)])]
       [() 1]
       [(a b c d . e*)
        (let f ([ac (binary* (binary* (binary* a b) c) d)]
@@ -926,20 +926,20 @@
             [(or (fixnum? y) (bignum? y)) 
              (binary-gcd x y)]
             [(number? y)
-             (error 'gcd "not an exact integer" y)]
+             (die 'gcd "not an exact integer" y)]
             [else 
-             (error 'gcd "not a number" y)])]
+             (die 'gcd "not a number" y)])]
          [(number? x)
-          (error 'gcd "not an exact integer" x)]
+          (die 'gcd "not an exact integer" x)]
          [else 
-          (error 'gcd "not a number" x)])]
+          (die 'gcd "not a number" x)])]
       [(x)
        (cond
          [(or (fixnum? x) (bignum? x)) x]
          [(number? x)
-          (error 'gcd "not an exact integer" x)]
+          (die 'gcd "not an exact integer" x)]
          [else 
-          (error 'gcd "not a number" x)])]
+          (die 'gcd "not a number" x)])]
       [() 0]
       [(x y z . ls) 
        (let f ([g (gcd (gcd x y) z)] [ls ls])
@@ -960,20 +960,20 @@
                (let ([g (binary-gcd x y)])
                  (binary* y (quotient x g))))]
             [(number? y)
-             (error 'lcm "not an exact integer" y)]
+             (die 'lcm "not an exact integer" y)]
             [else 
-             (error 'lcm "not a number" y)])]
+             (die 'lcm "not a number" y)])]
          [(number? x)
-          (error 'lcm "not an exact integer" x)]
+          (die 'lcm "not an exact integer" x)]
          [else 
-          (error 'lcm "not a number" x)])]
+          (die 'lcm "not a number" x)])]
       [(x)
        (cond
          [(or (fixnum? x) (bignum? x)) x]
          [(number? x)
-          (error 'lcm "not an exact integer" x)]
+          (die 'lcm "not an exact integer" x)]
          [else 
-          (error 'lcm "not a number" x)])]
+          (die 'lcm "not a number" x)])]
       [() 1]
       [(x y z . ls) 
        (let f ([g (lcm (lcm x y) z)] [ls ls])
@@ -993,13 +993,13 @@
            [(fixnum? y) ($fl/ x ($fixnum->flonum y))]
            [(bignum? y) ($fl/ x (bignum->flonum y))]
            [(ratnum? y) ($fl/ x (ratnum->flonum y))]
-           [else (error '/ "not a number" y)])]
+           [else (die '/ "not a number" y)])]
         [(fixnum? x)
          (cond
            [(flonum? y) ($fl/ ($fixnum->flonum x) y)]
            [(fixnum? y)
             (cond
-              [($fx= y 0) (error '/ "division by 0")]
+              [($fx= y 0) (die '/ "division by 0")]
               [($fx> y 0)
                (if ($fx= y 1)
                    x
@@ -1035,12 +1035,12 @@
                         (binary- 0 (quotient y g))))]))]
            [(ratnum? y) 
             (/ (* x ($ratnum-d y)) ($ratnum-n y))]
-           [else (error '/ "not a number" y)])]
+           [else (die '/ "not a number" y)])]
         [(bignum? x) 
          (cond
            [(fixnum? y) 
             (cond
-              [($fx= y 0) (error '/ "division by 0")]
+              [($fx= y 0) (die '/ "division by 0")]
               [($fx> y 0)
                (if ($fx= y 1)
                    x
@@ -1077,7 +1077,7 @@
            [(flonum? y) ($fl/ (bignum->flonum x) y)]
            [(ratnum? y) 
             (binary/ (binary* x ($ratnum-n y)) ($ratnum-d y))]
-           [else (error '/ "not a number" y)])]
+           [else (die '/ "not a number" y)])]
         [(ratnum? x)
          (cond
            [(ratnum? y) 
@@ -1085,7 +1085,7 @@
               (binary* ($ratnum-n x) ($ratnum-d y))
               (binary* ($ratnum-n y) ($ratnum-d x)))]
            [else (binary/ 1 (binary/ y x))])]
-        [else (error '/ "not a number" x)])))
+        [else (die '/ "not a number" x)])))
 
   (define /
     (case-lambda
@@ -1094,7 +1094,7 @@
        (cond
          [(fixnum? x)
           (cond
-            [($fxzero? x) (error '/ "division by 0")]
+            [($fxzero? x) (die '/ "division by 0")]
             [($fx> x 0)
              (if ($fx= x 1)
                  1
@@ -1114,7 +1114,7 @@
               [($fx= n 1) d]
               [($fx= n -1) (- d)]
               [else ($make-ratnum d n)]))]
-         [else (error '/ "not a number" x)])]
+         [else (die '/ "not a number" x)])]
       [(x y z . rest)
        (let f ([a (binary/ x y)] [b z] [ls rest])
          (cond
@@ -1130,8 +1130,8 @@
                (if ($fl< x y) 
                    y
                    x)
-               (error 'flmax "not a flonum" y))
-           (error 'flmax "not a flonum" x))]
+               (die 'flmax "not a flonum" y))
+           (die 'flmax "not a flonum" x))]
       [(x y z . rest)
        (let f ([a (flmax x y)] [b z] [ls rest])
          (cond
@@ -1141,7 +1141,7 @@
       [(x) 
        (if (flonum? x) 
            x 
-           (error 'flmax "not a number" x))]))
+           (die 'flmax "not a number" x))]))
 
   (define max
     (case-lambda
@@ -1158,7 +1158,7 @@
                (if ($fl>= y x) y x))]
             [(ratnum? y) ;;; FIXME: optimize
              (if (>= x y) x y)]
-            [else (error 'max "not a number" y)])]
+            [else (die 'max "not a number" y)])]
          [(bignum? x)
           (cond
             [(fixnum? y)
@@ -1170,7 +1170,7 @@
                (if ($fl>= y x) y x))]
             [(ratnum? y) ;;; FIXME: optimize
              (if (>= x y) x y)]
-            [else (error 'max "not a number" y)])]
+            [else (die 'max "not a number" y)])]
          [(flonum? x) 
           (cond
             [(flonum? y) 
@@ -1185,7 +1185,7 @@
              ;;; FIXME: may be incorrect
              (let ([y (ratnum->flonum y)])
                (if ($fl>= y x) y x))]
-            [else (error 'max "not a number" y)])]
+            [else (die 'max "not a number" y)])]
          [(ratnum? x) 
           (cond
             [(or (fixnum? y) (bignum? y) (ratnum? y))
@@ -1193,8 +1193,8 @@
             [(flonum? y) 
              (let ([x (ratnum->flonum x)])
                (if ($fl>= x y) x y))]
-            [else (error 'max "not a number" y)])]
-         [else (error 'max "not a number" x)])]
+            [else (die 'max "not a number" y)])]
+         [else (die 'max "not a number" x)])]
       [(x y z . rest)
        (let f ([a (max x y)] [b z] [ls rest])
          (cond
@@ -1204,7 +1204,7 @@
       [(x) 
        (if (number? x) 
            x 
-           (error 'max "not a number" x))]))
+           (die 'max "not a number" x))]))
 
   (define min
     (case-lambda
@@ -1221,7 +1221,7 @@
                (if ($fl>= y x) x y))]
             [(ratnum? y) ;;; FIXME: optimize
              (if (>= x y) y x)]
-            [else (error 'min "not a number" y)])]
+            [else (die 'min "not a number" y)])]
          [(bignum? x)
           (cond
             [(fixnum? y)
@@ -1233,7 +1233,7 @@
                (if ($fl>= y x) x y))]
             [(ratnum? y) ;;; FIXME: optimize
              (if (>= x y) y x)]
-            [else (error 'min "not a number" y)])]
+            [else (die 'min "not a number" y)])]
          [(flonum? x) 
           (cond
             [(flonum? y) 
@@ -1248,7 +1248,7 @@
              ;;; FIXME: may be incorrect
              (let ([y (ratnum->flonum y)])
                (if ($fl>= y x) x y))]
-            [else (error 'min "not a number" y)])]
+            [else (die 'min "not a number" y)])]
          [(ratnum? x) 
           (cond
             [(or (fixnum? y) (bignum? y) (ratnum? y))
@@ -1256,8 +1256,8 @@
             [(flonum? y) 
              (let ([x (ratnum->flonum x)])
                (if ($fl>= x y) y x))]
-            [else (error 'min "not a number" y)])]
-         [else (error 'min "not a number" x)])]
+            [else (die 'min "not a number" y)])]
+         [else (die 'min "not a number" x)])]
       [(x y z . rest)
        (let f ([a (min x y)] [b z] [ls rest])
          (cond
@@ -1267,7 +1267,7 @@
       [(x) 
        (if (number? x) 
            x 
-           (error 'min "not a number" x))]))
+           (die 'min "not a number" x))]))
 
   (define (abs x)
     (cond
@@ -1284,7 +1284,7 @@
          (if (< n 0) 
              ($make-ratnum (- n) ($ratnum-d x))
              x))]
-      [else (error 'abs "not a number" x)]))
+      [else (die 'abs "not a number" x)]))
 
   (define flmin
     (case-lambda
@@ -1292,8 +1292,8 @@
        (if (flonum? x)
            (if (flonum? y) 
                (if ($fl< x y) x y)
-               (error 'flmin "not a flonum" y))
-           (error 'flmin "not a flonum" x))]
+               (die 'flmin "not a flonum" y))
+           (die 'flmin "not a flonum" x))]
       [(x y z . rest)
        (let f ([a (flmin x y)] [b z] [ls rest])
          (cond
@@ -1303,7 +1303,7 @@
       [(x) 
        (if (flonum? x) 
            x 
-           (error 'flmin "not a flonum" x))]))
+           (die 'flmin "not a flonum" x))]))
 
   (define exact->inexact
     (lambda (x)
@@ -1312,7 +1312,7 @@
         [(bignum? x) (bignum->flonum x)]
         [(ratnum? x) (ratnum->flonum x)]
         [else
-         (error 'exact->inexact 
+         (die 'exact->inexact 
                 "not an exact number" x)])))
 
   (define inexact
@@ -1323,7 +1323,7 @@
         [(ratnum? x) (ratnum->flonum x)]
         [(flonum? x) x]
         [else
-         (error 'inexact "not a number" x)])))
+         (die 'inexact "not a number" x)])))
 
   (define real->flonum
     (lambda (x)
@@ -1333,7 +1333,7 @@
         [(ratnum? x) (ratnum->flonum x)]
         [(flonum? x) x]
         [else
-         (error 'real->flonum "not a real number" x)])))
+         (die 'real->flonum "not a real number" x)])))
 
   (define positive-bignum?
     (lambda (x) 
@@ -1350,16 +1350,16 @@
     (cond
       [(fixnum? x) ($fxeven? x)]
       [(bignum? x) (even-bignum? x)]
-      [(flonum? x) (error 'even? "BUG" x)]
-      [else (error 'even? "not an integer" x)]))
+      [(flonum? x) (die 'even? "BUG" x)]
+      [else (die 'even? "not an integer" x)]))
 
   (define (odd? x)
     (not
       (cond
         [(fixnum? x) ($fxeven? x)]
         [(bignum? x) (even-bignum? x)]
-        [(flonum? x) (error 'odd? "BUG" x)]
-        [else (error 'odd? "not an integer" x)])))
+        [(flonum? x) (die 'odd? "BUG" x)]
+        [else (die 'odd? "not an integer" x)])))
   
   (module (number->string)
     (module (bignum->string)
@@ -1406,7 +1406,7 @@
           [(2)  (bignum->power-string x  1 1)]
           [(8)  (bignum->power-string x  7 3)]
           [(16) (bignum->power-string x 15 4)]
-          [else (error 'number->string "BUG")])))
+          [else (die 'number->string "BUG")])))
     (define ratnum->string
       (lambda (x r) 
         (string-append 
@@ -1420,21 +1420,21 @@
           [(bignum? x) (bignum->string x r)]
           [(flonum? x) 
            (unless (eqv? r 10) 
-             (error 'number->string 
+             (die 'number->string 
                 "invalid radix for inexact number"
                 r x))
            (flonum->string x)]
           [(ratnum? x) (ratnum->string x r)]
-          [else (error 'number->string "not a number" x)])))
+          [else (die 'number->string "not a number" x)])))
     (define number->string
       (case-lambda
         [(x) ($number->string x 10)]
         [(x r) 
          (unless (memv r '(2 8 10 16)) 
-           (error 'number->string "invalid radix" r))
+           (die 'number->string "invalid radix" r))
          ($number->string x r)]
         [(x r precision)
-         (error 'number->string 
+         (die 'number->string 
             "BUG: precision is not supported yet")])))
 
   (define modulo
@@ -1456,9 +1456,9 @@
               (cond
                 [v (inexact (modulo n v))]
                 [else
-                 (error 'modulo "not an integer" m)]))]
-           [(ratnum? m) (error 'modulo "not an integer" m)]
-           [else (error 'modulo "not a number" m)])]
+                 (die 'modulo "not an integer" m)]))]
+           [(ratnum? m) (die 'modulo "not an integer" m)]
+           [else (die 'modulo "not a number" m)])]
         [(bignum? n)
          (cond
            [(fixnum? m) 
@@ -1476,17 +1476,17 @@
               (cond
                 [v (inexact (modulo n v))]
                 [else
-                 (error 'modulo "not an integer" m)]))] 
-           [(ratnum? m) (error 'modulo "not an integer" m)]
-           [else (error 'modulo "not a number" m)])]
+                 (die 'modulo "not an integer" m)]))] 
+           [(ratnum? m) (die 'modulo "not an integer" m)]
+           [else (die 'modulo "not a number" m)])]
         [(flonum? n) 
          (let ([v ($flonum->integer n)])
            (cond
              [v (inexact (modulo v m))]
              [else
-              (error 'modulo "not an integer" n)]))]
-        [(ratnum? n) (error 'modulo "not an integer" n)]
-        [else (error 'modulo "not a number" n)])))
+              (die 'modulo "not an integer" n)]))]
+        [(ratnum? n) (die 'modulo "not an integer" n)]
+        [else (die 'modulo "not a number" n)])))
 
   (define-syntax mk<
     (syntax-rules ()
@@ -1495,7 +1495,7 @@
                fxrt< rtfx< bnrt< rtbn< flrt< rtfl< rtrt<)
        (let ()
          (define err
-           (lambda (x) (error 'name "not a number" x)))
+           (lambda (x) (die 'name "not a number" x)))
          (define fxloopt
            (lambda (x y ls)
              (cond
@@ -1712,24 +1712,24 @@
             (if (flonum? x)
                 (if (flonum? y) 
                     ($fl< x y)
-                    (error 'fl<? "not a flonum" y))
-                (error 'fl<? "not a flonum" x))]
+                    (die 'fl<? "not a flonum" y))
+                (die 'fl<? "not a flonum" x))]
            [(x y z) 
             (if (flonum? x)
                 (if (flonum? y) 
                     (if (flonum? z) 
                         (and ($fl< x y) ($fl< y z))
-                        (error 'fl<? "not a flonum" z))
-                    (error 'fl<? "not a flonum" y))
-                (error 'fl<? "not a flonum" x))]
+                        (die 'fl<? "not a flonum" z))
+                    (die 'fl<? "not a flonum" y))
+                (die 'fl<? "not a flonum" x))]
            [(x) 
             (or (flonum? x)
-                (error 'fl<? "not a flonum" x))]
+                (die 'fl<? "not a flonum" x))]
            [(x y . rest) 
             (let ()
               (define (loopf a ls)
                 (unless (flonum? a) 
-                  (error 'fl<? "not a flonum" a))
+                  (die 'fl<? "not a flonum" a))
                 (if (null? ls) 
                     #f
                     (loopf (car ls) (cdr ls))))
@@ -1743,10 +1743,10 @@
                                     (if ($fl< x y) 
                                         (f y (car ls) (cdr ls))
                                         (loopf (car ls) (cdr ls))))
-                                (error 'fl<? "not a flonum" y)))
+                                (die 'fl<? "not a flonum" y)))
                           (loopf (car rest) (cdr rest)))
-                      (error 'fl<? "not a flonum" y))
-                  (error 'fl<? "not a flonum" x)))]))]))
+                      (die 'fl<? "not a flonum" y))
+                  (die 'fl<? "not a flonum" x)))]))]))
   (define-flcmp fl=? $fl=)
   (define-flcmp fl<? $fl<)
   (define-flcmp fl<=? $fl<=)
@@ -1759,8 +1759,8 @@
        (if (flonum? x)
            (if (flonum? y) 
                ($fl+ x y)
-               (error 'fl+ "not a flonum" y))
-           (error 'fl+ "not a flonum" x))]
+               (die 'fl+ "not a flonum" y))
+           (die 'fl+ "not a flonum" x))]
       [(x y z) 
        (fl+ (fl+ x y) z)]
       [(x y z q . rest)
@@ -1771,7 +1771,7 @@
       [(x) 
        (if (flonum? x) 
            x
-           (error 'fl+ "not a flonum" x))]
+           (die 'fl+ "not a flonum" x))]
       [() (exact->inexact 0)]))
 
 
@@ -1781,8 +1781,8 @@
        (if (flonum? x)
            (if (flonum? y) 
                ($fl- x y)
-               (error 'fl- "not a flonum" y))
-           (error 'fl- "not a flonum" x))]
+               (die 'fl- "not a flonum" y))
+           (die 'fl- "not a flonum" x))]
       [(x y z) 
        (fl- (fl- x y) z)]
       [(x y z q . rest)
@@ -1793,7 +1793,7 @@
       [(x) 
        (if (flonum? x) 
            ($fl* -1.0 x)
-           (error 'fl+ "not a flonum" x))]))
+           (die 'fl+ "not a flonum" x))]))
 
   (define fl*
     (case-lambda
@@ -1801,8 +1801,8 @@
        (if (flonum? x)
            (if (flonum? y) 
                ($fl* x y)
-               (error 'fl* "not a flonum" y))
-           (error 'fl* "not a flonum" x))]
+               (die 'fl* "not a flonum" y))
+           (die 'fl* "not a flonum" x))]
       [(x y z) 
        (fl* (fl* x y) z)]
       [(x y z q . rest)
@@ -1813,7 +1813,7 @@
       [(x) 
        (if (flonum? x) 
            x
-           (error 'fl* "not a flonum" x))]
+           (die 'fl* "not a flonum" x))]
       [() 1.0]))
 
   (define fl/
@@ -1822,8 +1822,8 @@
        (if (flonum? x)
            (if (flonum? y) 
                ($fl/ x y)
-               (error 'fl/ "not a flonum" y))
-           (error 'fl/ "not a flonum" x))]
+               (die 'fl/ "not a flonum" y))
+           (die 'fl/ "not a flonum" x))]
       [(x y z) 
        (fl/ (fl/ x y) z)]
       [(x y z q . rest)
@@ -1834,7 +1834,7 @@
       [(x) 
        (if (flonum? x) 
            ($fl/ 1.0 x)
-           (error 'fl/ "not a flonum" x))])) 
+           (die 'fl/ "not a flonum" x))])) 
 
   (flcmp flfl= flfx= fxfl= flbn= bnfl= $fl=)
   (flcmp flfl< flfx< fxfl< flbn< bnfl< $fl<)
@@ -1886,7 +1886,7 @@
          (foreign-call "ikrt_fxfxplus" x 1)]
         [(bignum? x)
          (foreign-call "ikrt_fxbnplus" 1 x)]
-        [else (error 'add1 "not a number" x)])))
+        [else (die 'add1 "not a number" x)])))
 
   (define sub1
     (lambda (x)
@@ -1895,7 +1895,7 @@
          (foreign-call "ikrt_fxfxplus" x -1)]
         [(bignum? x)
          (foreign-call "ikrt_fxbnplus" -1 x)]
-        [else (error 'sub1 "not a number" x)])))
+        [else (die 'sub1 "not a number" x)])))
 
   (define zero?
     (lambda (x)
@@ -1905,7 +1905,7 @@
         [(flonum? x)
          (or ($fl= x 0.0) ($fl= x -0.0))]
         [else 
-         (error 'zero? "not a number" x)])))
+         (die 'zero? "not a number" x)])))
 
   (define expt
     (lambda (n m)
@@ -1918,7 +1918,7 @@
             [else
              (binary* n (fxexpt (binary* n n) ($fxsra m 1)))])))
       (unless (number? n)
-        (error 'expt "not a numebr" n))
+        (die 'expt "not a numebr" n))
       (cond
         [(fixnum? m) 
          (if ($fx>= m 0)
@@ -1935,10 +1935,10 @@
                     -1)
                 (/ 1 (expt n (- m))))]
            [else 
-            (error 'expt "result is too big to compute" n m)])]
+            (die 'expt "result is too big to compute" n m)])]
         [(flonum? m) (flexpt (inexact n) m)]
         [(ratnum? m) (flexpt (inexact n) (inexact m))]
-        [else (error 'expt "not a number" m)])))
+        [else (die 'expt "not a number" m)])))
 
   (define quotient
     (lambda (x y)
@@ -1954,7 +1954,7 @@
     (lambda (x y)
       (cond
         [(eq? y 0) 
-         (error 'quotient+remainder
+         (die 'quotient+remainder
                 "second argument must be non-zero")]
         [(fixnum? x) 
          (cond
@@ -1969,8 +1969,8 @@
                  (let-values ([(q r) (quotient+remainder x v)])
                    (values (inexact q) (inexact r)))]
                 [else
-                 (error 'quotient+remainder "not an integer" y)]))]
-           [else (error 'quotient+remainder "not a number" y)])]
+                 (die 'quotient+remainder "not an integer" y)]))]
+           [else (die 'quotient+remainder "not a number" y)])]
         [(bignum? x)
          (cond
            [(fixnum? y)
@@ -1986,16 +1986,16 @@
                  (let-values ([(q r) (quotient+remainder x v)])
                    (values (inexact q) (inexact r)))]
                 [else
-                 (error 'quotient+remainder "not an integer" y)]))] 
-           [else (error 'quotient+remainder "not a number" y)])]
+                 (die 'quotient+remainder "not an integer" y)]))] 
+           [else (die 'quotient+remainder "not a number" y)])]
         [(flonum? x) 
          (let ([v ($flonum->integer x)])
            (cond
              [v
               (let-values ([(q r) (quotient+remainder v y)])
                 (values (inexact q) (inexact r)))]
-             [else (error 'quotient+remainder "not an integer" x)]))]
-        [else (error 'quotient+remainder "not a number" x)])))
+             [else (die 'quotient+remainder "not an integer" x)]))]
+        [else (die 'quotient+remainder "not a number" x)])))
 
   (define positive?
     (lambda (x)
@@ -2004,7 +2004,7 @@
         [(flonum? x) ($fl> x 0.0)]
         [(bignum? x) (positive-bignum? x)]
         [(ratnum? x) (positive? ($ratnum-n x))]
-        [else (error 'positive? "not a number" x)])))
+        [else (die 'positive? "not a number" x)])))
 
   (define negative?
     (lambda (x)
@@ -2013,76 +2013,76 @@
         [(flonum? x) ($fl< x 0.0)]
         [(bignum? x) (not (positive-bignum? x))]
         [(ratnum? x) (negative? ($ratnum-n x))]
-        [else (error 'negative? "not a number" x)])))
+        [else (die 'negative? "not a number" x)])))
 
   (define sin
     (lambda (x)
       (cond
         [(flonum? x) (foreign-call "ikrt_fl_sin" x)]
         [(fixnum? x) (foreign-call "ikrt_fx_sin" x)]
-        [else (error 'sin "BUG: unsupported" x)])))
+        [else (die 'sin "BUG: unsupported" x)])))
 
   (define cos
     (lambda (x)
       (cond
         [(flonum? x) (foreign-call "ikrt_fl_cos" x)]
         [(fixnum? x) (foreign-call "ikrt_fx_cos" x)]
-        [else (error 'cos "BUG: unsupported" x)])))
+        [else (die 'cos "BUG: unsupported" x)])))
 
   (define tan
     (lambda (x)
       (cond
         [(flonum? x) (foreign-call "ikrt_fl_tan" x)]
         [(fixnum? x) (foreign-call "ikrt_fx_tan" x)]
-        [else (error 'tan "BUG: unsupported" x)])))
+        [else (die 'tan "BUG: unsupported" x)])))
 
   (define asin
     (lambda (x)
       (cond
         [(flonum? x) (foreign-call "ikrt_fl_asin" x)]
         [(fixnum? x) (foreign-call "ikrt_fx_asin" x)]
-        [else (error 'asin "BUG: unsupported" x)])))
+        [else (die 'asin "BUG: unsupported" x)])))
 
   (define acos
     (lambda (x)
       (cond
         [(flonum? x) (foreign-call "ikrt_fl_acos" x)]
         [(fixnum? x) (foreign-call "ikrt_fx_acos" x)]
-        [else (error 'acos "BUG: unsupported" x)])))
+        [else (die 'acos "BUG: unsupported" x)])))
 
   (define atan
     (lambda (x)
       (cond
         [(flonum? x) (foreign-call "ikrt_fl_atan" x)]
         [(fixnum? x) (foreign-call "ikrt_fx_atan" x)]
-        [else (error 'atan "BUG: unsupported" x)])))
+        [else (die 'atan "BUG: unsupported" x)])))
 
   (define sqrt
     (lambda (x)
       (cond
         [(flonum? x) (foreign-call "ikrt_fl_sqrt" x)]
         [(fixnum? x) (foreign-call "ikrt_fx_sqrt" x)]
-        [(bignum? x) (error 'sqrt "BUG: bignum sqrt not implemented")]
+        [(bignum? x) (die 'sqrt "BUG: bignum sqrt not implemented")]
         [(ratnum? x) (/ (sqrt ($ratnum-n x)) (sqrt ($ratnum-d x)))]
-        [else (error 'sqrt "BUG: unsupported" x)])))
+        [else (die 'sqrt "BUG: unsupported" x)])))
 
   (define flsqrt
     (lambda (x)
       (if (flonum? x) 
           (foreign-call "ikrt_fl_sqrt" x)
-          (error 'flsqrt "not a flonum" x))))
+          (die 'flsqrt "not a flonum" x))))
 
   (define flzero?
     (lambda (x)
       (if (flonum? x) 
           ($flzero? x)
-          (error 'flzero? "not a flonum" x))))
+          (die 'flzero? "not a flonum" x))))
 
   (define flnegative?
     (lambda (x)
       (if (flonum? x) 
           ($fl< x 0.0)
-          (error 'flnegative? "not a flonum" x))))
+          (die 'flnegative? "not a flonum" x))))
 
   (define exact-integer-sqrt
     (lambda (x)
@@ -2106,7 +2106,7 @@
       (cond
         [(fixnum? x) 
          (cond
-           [($fx< x 0) (error who "invalid argument" x)]
+           [($fx< x 0) (die who "invalid argument" x)]
            [($fx= x 0) (values 0 0)]
            [($fx< x 4) (values 1 ($fx- x 1))]
            [($fx< x 9) (values 2 ($fx- x 4))]
@@ -2116,8 +2116,8 @@
          (cond
            [($bignum-positive? x) 
             (bnsqrt x 23170 (quotient x 23170))]
-           [else (error who "invalid argument" x)])]
-        [else (error who "invalid argument" x)])))
+           [else (die who "invalid argument" x)])]
+        [else (die who "invalid argument" x)])))
 
 
   (define numerator
@@ -2126,7 +2126,7 @@
         [(ratnum? x) ($ratnum-n x)]
         [(or (fixnum? x) (bignum? x)) x]
         [(flonum? x) (flnumerator x)]
-        [else (error 'numerator "not an exact integer" x)])))
+        [else (die 'numerator "not an exact integer" x)])))
 
   (define denominator
     (lambda (x)
@@ -2134,7 +2134,7 @@
         [(ratnum? x) ($ratnum-d x)]
         [(or (fixnum? x) (bignum? x)) 1]
         [(flonum? x) (fldenominator x)]
-        [else (error 'denominator "not an exact integer" x)])))
+        [else (die 'denominator "not an exact integer" x)])))
 
 
   (define (floor x)
@@ -2146,14 +2146,14 @@
       [(flonum? x) 
        ;;; optimize for integer flonums
        (let ([e (or ($flonum->exact x)
-                    (error 'floor "number has no real value" x))])
+                    (die 'floor "number has no real value" x))])
          (cond
            [(ratnum? e) 
             (exact->inexact (ratnum-floor e))] 
            [else x]))]
       [(ratnum? x) (ratnum-floor x)]
       [(or (fixnum? x) (bignum? x)) x]
-      [else (error 'floor "not a number" x)]))
+      [else (die 'floor "not a number" x)]))
   
   (define (ceiling x)
     (define (ratnum-ceiling x)
@@ -2164,13 +2164,13 @@
       [(flonum? x) 
        ;;; optimize for integer flonums
        (let ([e (or ($flonum->exact x)
-                    (error 'ceiling "number has no real value" x))])
+                    (die 'ceiling "number has no real value" x))])
          (cond
            [(ratnum? e) (exact->inexact (ratnum-ceiling e))] 
            [else x]))]
       [(ratnum? x) (ratnum-ceiling x)]
       [(or (fixnum? x) (bignum? x)) x]
-      [else (error 'ceiling "not a number" x)]))
+      [else (die 'ceiling "not a number" x)]))
 
 
   (define ($ratnum-round x)
@@ -2200,7 +2200,7 @@
       [(flonum? x) ($flround x)]
       [(ratnum? x) ($ratnum-round x)]
       [(or (fixnum? x) (bignum? x)) x]
-      [else (error 'round "not a number" x)]))
+      [else (die 'round "not a number" x)]))
 
   (define (truncate x)
     ;;; FIXME: fltruncate should preserve the sign of -0.0.
@@ -2208,19 +2208,19 @@
     (cond
       [(flonum? x) 
        (let ([e (or ($flonum->exact x) 
-                    (error 'truncate "number has no real value" x))])
+                    (die 'truncate "number has no real value" x))])
          (cond
            [(ratnum? e) (exact->inexact ($ratnum-truncate e))]
            [else x]))]
       [(ratnum? x) ($ratnum-truncate x)]
       [(or (fixnum? x) (bignum? x)) x]
-      [else (error 'truncate "not a number" x)]))
+      [else (die 'truncate "not a number" x)]))
   
 
   (define (fltruncate x)
     ;;; FIXME: fltruncate should preserve the sign of -0.0.
     (unless (flonum? x)
-      (error 'fltruncate "not a flonum" x))
+      (die 'fltruncate "not a flonum" x))
     (let ([v ($flonum->exact x)])
       (cond
         [(ratnum? v) (exact->inexact ($ratnum-truncate v))]
@@ -2232,23 +2232,23 @@
         [(fixnum? x) 
          (cond
            [($fx= x 1) 0]
-           [($fx= x 0) (error 'log "undefined around 0")]
+           [($fx= x 0) (die 'log "undefined around 0")]
            [($fx> x 0) (foreign-call "ikrt_fx_log" x)]
-           [else (error 'log "negative argument" x)])]
+           [else (die 'log "negative argument" x)])]
         [(flonum? x) 
          (cond
            [(>= x 0) (foreign-call "ikrt_fl_log" x)]
-           [else (error 'log "negative argument" x)])]
+           [else (die 'log "negative argument" x)])]
         [(bignum? x) (log (exact->inexact x))]
         [(ratnum? x) (- (log (numerator x)) (log (denominator x)))]
-        [else (error 'log "not a number" x)])))
+        [else (die 'log "not a number" x)])))
 
   (define string->number
     (case-lambda
       [(x) (string->number-radix-10 x)]
       [(x r) 
        (unless (eqv? r 10) 
-         (error 'string->number
+         (die 'string->number
                 "BUG: only radix 10 is supported"
                 x r))
        (string->number-radix-10 x)]))
@@ -2281,7 +2281,7 @@
              [(#\0) 0]
              [(#\1) 1]
              [else #f])]
-          [else (error 'convert-char "invalid radix" radix)]))
+          [else (die 'convert-char "invalid radix" radix)]))
       (define (parse-exponent-start x n i radix)
         (define (parse-exponent x n i radix ac) 
           (cond
@@ -2443,7 +2443,7 @@
                [else #f]))]))
       ;;;
       (unless (string? x)
-        (error 'string->number "not a string" x))
+        (die 'string->number "not a string" x))
       (let ([n (string-length x)])
         (cond
           [(fx= n (string-length "+xxx.0"))
@@ -2463,8 +2463,8 @@
             (foreign-call "ikrt_fxrandom" n) 
             (if (fx= n 1) 
                 0
-                (error 'random "incorrect argument" n)))
-        (error 'random "not a fixnum" n)))
+                (die 'random "incorrect argument" n)))
+        (die 'random "not a fixnum" n)))
 
 
   (define (shift-right-arithmetic n m who) 
@@ -2474,41 +2474,41 @@
          [(fixnum? n) 
           (cond
             [($fx>= m 0) ($fxsra n m)]
-            [else (error who "offset must be non-negative" m)])]
+            [else (die who "offset must be non-negative" m)])]
          [(bignum? n) 
           (cond
             [($fx> m 0)  
              (foreign-call "ikrt_bignum_shift_right" n m)]
             [($fx= m 0) n]
-            [else (error who "offset must be non-negative" m)])]
-         [else (error who "not an exact integer" n)])]
+            [else (die who "offset must be non-negative" m)])]
+         [else (die who "not an exact integer" n)])]
       [(bignum? m) 
        (cond
          [(fixnum? n) (if ($fx>= n 0) 0 -1)]
          [(bignum? n) (if ($bignum-positive? n) 0 -1)]
-         [else (error who "not an exact integer" n)])]
-      [else (error who "not an exact integer offset" m)]))
+         [else (die who "not an exact integer" n)])]
+      [else (die who "not an exact integer offset" m)]))
 
   (define (sra n m)
     (shift-right-arithmetic n m 'sra))
 
   (define (shift-left-logical n m who) 
     (unless (fixnum? m)
-      (error who "shift amount is not a fixnum"))
+      (die who "shift amount is not a fixnum"))
     (cond
       [(fixnum? n)
        (cond
          [($fx> m 0) 
           (foreign-call "ikrt_fixnum_shift_left" n m)]
          [($fx= m 0) n]
-         [else (error who "offset must be non-negative" m)])]
+         [else (die who "offset must be non-negative" m)])]
       [(bignum? n) 
        (cond
          [($fx> m 0) 
           (foreign-call "ikrt_bignum_shift_left" n m)]
          [($fx= m 0) n]
-         [else (error who "offset must be non-negative" m)])]
-      [else (error who "not an exact integer" n)]))
+         [else (die who "offset must be non-negative" m)])]
+      [else (die who "not an exact integer" n)]))
 
   (define (sll n m)
     (shift-left-logical n m 'sll))
@@ -2520,7 +2520,7 @@
   (define (bitwise-arithmetic-shift n m)
     (define who 'bitwise-arithmetic-shift)
     (unless (fixnum? m)
-      (error who "shift amount is not a fixnum"))
+      (die who "shift amount is not a fixnum"))
     (cond
       [(fixnum? n)
        (cond
@@ -2530,7 +2530,7 @@
          [else
           (let ([m^ (- m)])
             (unless (fixnum? m^) 
-              (error who "shift amount is too big" m))
+              (die who "shift amount is too big" m))
             ($fxsra n m^))])]
       [(bignum? n)
        (cond
@@ -2540,9 +2540,9 @@
          [else
           (let ([m^ (- m)])
             (unless (fixnum? m^) 
-              (error who "shift amount is too big" m))
+              (die who "shift amount is too big" m))
             (foreign-call "ikrt_bignum_shift_right" n m^))])]
-      [else (error who "not an exact integer" n)]))
+      [else (die who "not an exact integer" n)]))
 
   (define (exp x) 
     (cond
@@ -2551,7 +2551,7 @@
        (if ($fx= x 0) 1 (flexp (fixnum->flonum x)))]
       [(bignum? x) (flexp (bignum->flonum x))]
       [(ratnum? x) (flexp (ratnum->flonum x))]
-      [else (error 'exp "not a number" x)]))
+      [else (die 'exp "not a number" x)]))
 
 
   )
@@ -2566,7 +2566,7 @@
     (lambda (x) 
       (if (number? x) 
           x
-          (error 'real-part "not a number" x))))
+          (die 'real-part "not a number" x))))
 
   (define imag-part
     (lambda (x)
@@ -2576,7 +2576,7 @@
         [(ratnum? x) 0]
         [(flonum? x) 0.0]
         [else 
-         (error 'imag-part "not a number" x)]))))
+         (die 'imag-part "not a number" x)]))))
 
 
 
@@ -2721,7 +2721,7 @@
                (if pos? "+inf.0" "-inf.0") 
                ;;; Gee!  nans have no sign!
                "+nan.0")]
-          [else (error 'flonum->string "cannot happen")]))))
+          [else (die 'flonum->string "cannot happen")]))))
   ;;;
   (define (string->flonum x)
     (cond
@@ -2729,7 +2729,7 @@
        (foreign-call "ikrt_bytevector_to_flonum" 
          (string->utf8 x))]
       [else 
-       (error 'string->flonum "not a string" x)])) )
+       (die 'string->flonum "not a string" x)])) )
 
 (library (ikarus rationalize)
   (export rationalize)
@@ -2771,21 +2771,21 @@
               (if (flfinite? eps) (go x eps) +nan.0)]
              [(or (fixnum? eps) (bignum? eps) (ratnum? eps))
               (go x eps)]
-             [else (error who "not a number" eps)])
+             [else (die who "not a number" eps)])
            (cond
              [(flonum? eps) 
               (if (flfinite? eps) x +nan.0)]
              [(or (fixnum? eps) (bignum? eps) (ratnum? eps))
               x]
-             [else (error who "not a number" eps)]))]
+             [else (die who "not a number" eps)]))]
       [(or (fixnum? x) (bignum? x) (ratnum? x))
        (cond
          [(flonum? eps) 
           (if (flfinite? eps) (go x eps) +nan.0)]
          [(or (fixnum? eps) (bignum? eps) (ratnum? eps))
           (go x eps)]
-         [else (error who "not a number" eps)])]
-      [else (error who "not a number" x)])))
+         [else (die who "not a number" eps)])]
+      [else (die who "not a number" x)])))
 
 
 (library (ikarus r6rs-fu div/mod)
@@ -2819,14 +2819,14 @@
       [(fixnum? m) 
        (cond
          [($fx= m 0) 
-          (error who "division by 0")]
+          (die who "division by 0")]
          [(or (fixnum? n) (bignum? n))
           (int-div-and-mod n m)]
          [(flonum? n) 
           (fldiv-and-mod n (fixnum->flonum m))]
          [(ratnum? n) 
           (rat-div-and-mod n m)]
-         [else (error who "not a number" n)])]
+         [else (die who "not a number" n)])]
       [(bignum? m) 
        (cond
          [(or (fixnum? n) (bignum? n))
@@ -2834,12 +2834,12 @@
          [(flonum? n) 
           (let ([v ($flonum->exact n)])
             (unless v 
-              (error who "invalid argument" n))
+              (die who "invalid argument" n))
             (let-values ([(a b) (div-and-mod* v m who)])
               (values (inexact a) (inexact b))))]
          [(ratnum? n) 
           (rat-div-and-mod n m)]
-         [else (error who "not a number" n)])]
+         [else (die who "not a number" n)])]
       [(ratnum? m) 
        (cond
          [(or (fixnum? n) (bignum? n) (ratnum? n))
@@ -2847,25 +2847,25 @@
          [(flonum? n) 
           (let ([v ($flonum->exact n)])
             (unless v 
-              (error who "invalid argument" n))
+              (die who "invalid argument" n))
             (let-values ([(a b) (div-and-mod* v m who)])
               (values (inexact a) (inexact b))))]
-         [else (error who "not a number" n)])]
+         [else (die who "not a number" n)])]
       [(flonum? m) 
        (cond
          [($fl= m 0.0) 
-          (error who "division by 0.0")]
+          (die who "division by 0.0")]
          [(flonum? n) (fldiv-and-mod n m)]
          [(fixnum? n) 
           (fldiv-and-mod (fixnum->flonum n) m)]
          [(or (bignum? n) (ratnum? n))
           (let ([v ($flonum->exact m)])
             (unless v 
-              (error who "invalid argument" m))
+              (die who "invalid argument" m))
             (let-values ([(a b) (div-and-mod* n v who)])
               (values (inexact a) (inexact b))))]
-         [else (error who "not a number" n)])]
-      [else (error who "not a number" m)]))
+         [else (die who "not a number" n)])]
+      [else (die who "not a number" m)]))
 
   (define (div-and-mod n m)
     (div-and-mod* n m 'div-and-mod))
@@ -2880,9 +2880,9 @@
   (define (div0-and-mod0 x y) 
     (define who 'div0-and-mod0)
     (unless (integer? x)
-      (error who "not an integer" x))
+      (die who "not an integer" x))
     (unless (and (integer? y) (not (= y 0)))
-      (error who "not an integer" y))
+      (die who "not an integer" y))
     (let-values ([(d m) (div-and-mod x y)])
       (if (> y 0) 
           (if (< m (/ y 2))
@@ -2939,22 +2939,22 @@
     (if (flonum? n)
         (if (flonum? m) 
             ($fldiv n m) 
-            (error 'fldiv "not a flonum" m))
-        (error 'fldiv "not a flonum" n)))
+            (die 'fldiv "not a flonum" m))
+        (die 'fldiv "not a flonum" n)))
   
   (define (flmod n m)
     (if (flonum? n)
         (if (flonum? m)
             ($flmod n m)
-            (error 'flmod "not a flonum" m))
-        (error 'flmod "not a flonum" n)))
+            (die 'flmod "not a flonum" m))
+        (die 'flmod "not a flonum" n)))
   
   (define (fldiv-and-mod n m)
     (if (flonum? n)
         (if (flonum? m) 
             ($fldiv-and-mod n m)
-            (error 'fldiv-and-mod "not a flonum" m))
-        (error 'fldiv-and-mod "not a flonum" n)))
+            (die 'fldiv-and-mod "not a flonum" m))
+        (die 'fldiv-and-mod "not a flonum" n)))
 
   (define ($fldiv0-and-mod0 n m)
     (let ([d0 (fltruncate ($fl/ n m))])
@@ -3005,22 +3005,22 @@
     (if (flonum? n)
         (if (flonum? m) 
             ($fldiv0 n m)
-            (error 'fldiv0 "not a flonum" m))
-        (error 'fldiv0 "not a flonum" n)))
+            (die 'fldiv0 "not a flonum" m))
+        (die 'fldiv0 "not a flonum" n)))
 
   (define (flmod0 n m)
     (if (flonum? n)
         (if (flonum? m) 
             ($flmod0 n m)
-            (error 'flmod0 "not a flonum" m))
-        (error 'flmod0 "not a flonum" n)))
+            (die 'flmod0 "not a flonum" m))
+        (die 'flmod0 "not a flonum" n)))
 
   (define (fldiv0-and-mod0 n m)
     (if (flonum? n)
         (if (flonum? m) 
             ($fldiv0-and-mod0 n m)
-            (error 'fldiv0-and-mod0 "not a flonum" m))
-        (error 'fldiv0-and-mod0 "not a flonum" n))))
+            (die 'fldiv0-and-mod0 "not a flonum" m))
+        (die 'fldiv0-and-mod0 "not a flonum" n))))
 
 (library (ikarus bitwise misc)
   (export fxfirst-bit-set bitwise-bit-set? bitwise-first-bit-set
@@ -3082,13 +3082,13 @@
       (cond
         [(fixnum? x) 
          ($fxfirst-bit-set x)]
-        [else (error 'fxfirst-bit-set "not a fixnum" x)]))
+        [else (die 'fxfirst-bit-set "not a fixnum" x)]))
     (define (bitwise-first-bit-set x)
       (cond
         [(fixnum? x) 
          ($fxfirst-bit-set x)]
         [(bignum? x) ($bnloop x 0 0)]
-        [else (error 'bitwise-first-bit-set "not an exact integer" x)])))
+        [else (die 'bitwise-first-bit-set "not an exact integer" x)])))
 
   (module (fxbit-count bitwise-bit-count)
     (define (pos-fxbitcount n)
@@ -3126,12 +3126,12 @@
     (define (fxbit-count n)
       (cond
         [(fixnum? n) ($fxbitcount n)]
-        [else (error 'fxbit-count "not a fixnum" n)]))
+        [else (die 'fxbit-count "not a fixnum" n)]))
     (define (bitwise-bit-count n)
       (cond
         [(fixnum? n) ($fxbitcount n)]
         [(bignum? n) (bnbitcount n)]
-        [else (error 'bitwise-bit-count "not an exact integer" n)])))
+        [else (die 'bitwise-bit-count "not an exact integer" n)])))
   
   (define (fxlength x) 
     (if (fixnum? x) 
@@ -3143,7 +3143,7 @@
             (cond
               [($fx= sbe 0) 0]
               [else ($fx- sbe 1022)])))
-        (error 'fxlength "not a fixnum" x)))
+        (die 'fxlength "not a fixnum" x)))
 
   (define (fxbit-set? x i)
     (define who 'fxbit-set?)
@@ -3151,16 +3151,16 @@
         (if (fixnum? i) 
             (if (and ($fx<= 0 i) ($fx< i (fixnum-width)))
                 (not ($fxzero? ($fxlogand ($fxsra x i) 1)))
-                (error who "index out of range" i))
-            (error who "index is not a fixnum" i))
-        (error who "not a fixnum" x)))
+                (die who "index out of range" i))
+            (die who "index is not a fixnum" i))
+        (die who "not a fixnum" x)))
 
   (define (bitwise-bit-set? x i)
     (define who 'bitwise-bit-set?)
     (cond
       [(fixnum? i) 
        (when ($fx< i 0) 
-         (error who "index must be non-negative" i))
+         (die who "index must be non-negative" i))
        (cond
          [(fixnum? x) 
           (if ($fx< i (fixnum-width))
@@ -3177,17 +3177,17 @@
                       (= 1 (bitwise-and
                              (bitwise-arithmetic-shift-right x i)
                              1))))))]
-         [else (error who "not an exact integer" x)])]
+         [else (die who "not an exact integer" x)])]
       [(bignum? i) 
        (unless ($bignum-positive? i) 
-         (error who "index must be non-negative"))
+         (die who "index must be non-negative"))
        (cond
          [(fixnum? x) ($fx< x 0)]
          [(bignum? x) 
           (= 1 (bitwise-and (bitwise-arithmetic-shift-right x i) 1))]
-         [else (error who "not an exact integer" x)])]
+         [else (die who "not an exact integer" x)])]
       [else 
-       (error who "index is not an exact integer" i)]))
+       (die who "index is not an exact integer" i)]))
 
 
   (define (fxcopy-bit x i b)
@@ -3198,10 +3198,10 @@
                 (case b
                   [(0) ($fxlogand x ($fxlognot ($fxsll 1 i)))]
                   [(1) ($fxlogor x ($fxsll 1 i))]
-                  [else (error who "invalid bit value" b)])
-                (error who "index out of range" i))
-            (error who "index is not a fixnum" i))
-        (error who "not a fixnum" x)))
+                  [else (die who "invalid bit value" b)])
+                (die who "index out of range" i))
+            (die who "index is not a fixnum" i))
+        (die who "not a fixnum" x)))
 
   (define (fxcopy-bit-field x i j b)
     (define who 'fxcopy-bit-field)
@@ -3219,15 +3219,15 @@
                                   ($fxlogor
                                     ($fxlogand m b)
                                     ($fxlogand ($fxlognot m) x)))
-                                (error who "not a fixnum" b))
+                                (die who "not a fixnum" b))
                             (if ($fx<= 0 j)
-                                (error who "index out of range" j)
-                                (error who "indices not in order" i j)))
-                        (error who "index out of range" j))
-                    (error who "not a fixnum" j))
-                (error who "index out of range" i))
-            (error who "not a fixnum" i))
-        (error who "not a fixnum" x)))
+                                (die who "index out of range" j)
+                                (die who "indices not in order" i j)))
+                        (die who "index out of range" j))
+                    (die who "not a fixnum" j))
+                (die who "index out of range" i))
+            (die who "not a fixnum" i))
+        (die who "not a fixnum" x)))
 
   (define (fxbit-field x i j)
     (define who 'fxbit-field)
@@ -3241,13 +3241,13 @@
                               ($fxlogand x ($fxsub1 ($fxsll 1 j)))
                               i)
                             (if ($fx<= 0 j)
-                                (error who "index out of range" j)
-                                (error who "indices not in order" i j)))
-                        (error who "index out of range" j))
-                    (error who "not a fixnum" j))
-                (error who "index out of range" i))
-            (error who "not a fixnum" i))
-        (error who "not a fixnum" x)))
+                                (die who "index out of range" j)
+                                (die who "indices not in order" i j)))
+                        (die who "index out of range" j))
+                    (die who "not a fixnum" j))
+                (die who "index out of range" i))
+            (die who "not a fixnum" i))
+        (die who "not a fixnum" x)))
 
   )
 
diff --git a/scheme/ikarus.pairs.ss b/scheme/ikarus.pairs.ss
index 834dd03..241cc61 100644
--- a/scheme/ikarus.pairs.ss
+++ b/scheme/ikarus.pairs.ss
@@ -39,13 +39,13 @@
   (define set-car!
     (lambda (x y) 
       (unless (pair? x)
-        (error 'set-car! "not a pair" x))
+        (die 'set-car! "not a pair" x))
       ($set-car! x y)))
   
   (define set-cdr! 
     (lambda (x y)
       (unless (pair? x)
-        (error 'set-cdr! "not a pair" x))
+        (die 'set-cdr! "not a pair" x))
       ($set-cdr! x y)))
 
   (define-syntax cxr
@@ -65,7 +65,7 @@
        (begin
          (define name*
            (lambda (x) 
-             ((cxr (error 'name* "invalid list structure" x) ops** ...)
+             ((cxr (die 'name* "invalid list structure" x) ops** ...)
               x)))
          ...)]))
 
diff --git a/scheme/ikarus.posix.ss b/scheme/ikarus.posix.ss
index 88cc6bb..84c12a4 100644
--- a/scheme/ikarus.posix.ss
+++ b/scheme/ikarus.posix.ss
@@ -33,55 +33,55 @@
         (cond
           [(fx= pid 0) (child-proc)]
           [(fx= pid -1) 
-           (error 'fork "failed")]
+           (die 'fork "failed")]
           [else (parent-proc pid)]))))
 
   (define waitpid
     (lambda (pid)
       (unless (fixnum? pid)
-        (error 'waitpid "not a fixnum" pid))
+        (die 'waitpid "not a fixnum" pid))
       (foreign-call "ikrt_waitpid" pid)))
 
   (define system
     (lambda (x)
       (unless (string? x)
-        (error 'system "not a string" x))
+        (die 'system "not a string" x))
       (let ([rv (foreign-call "ik_system"
                   (string->utf8 x))])
         (if (fx= rv -1)
-            (error 'system "failed")
+            (die 'system "failed")
             rv))))
 
   (define file-exists?
     (lambda (x)
       (unless (string? x)
-        (error 'file-exists? "filename is not a string" x))
+        (die 'file-exists? "filename is not a string" x))
       (let ([v (foreign-call "ikrt_file_exists" 
                   (string->utf8 x))])
         (cond
           [(boolean? v) v]
           [else
-           (error 'file-exists?
+           (die 'file-exists?
                   (case v
                     [(1) "the path contains a non-directory"]
                     [(2) "the path is too long"]
                     [(3) "the path is not accessible"]
                     [(4) "the path contains too many symbolic links"]
-                    [(5) "internal access error while accessing"]
-                    [(6) "IO error encountered while accessing"]
-                    [else "Unknown error"])
+                    [(5) "internal access die while accessing"]
+                    [(6) "IO die encountered while accessing"]
+                    [else "Unknown die"])
                   x)]))))
 
   (define delete-file
     (lambda (x)
       (unless (string? x)
-        (error 'delete-file "filename is not a string" x))
+        (die 'delete-file "filename is not a string" x))
       (let ([v (foreign-call "ikrt_delete_file"
                  (string->utf8 x))])
         (case v
           [(0) (void)]
           [else
-           (error 'delete-file
+           (die 'delete-file
                   (case v
                     [(1) "the path contains a non-directory"]
                     [(2) "the path is too long"]
@@ -90,10 +90,10 @@
                     [(5) "the path contains too many symbolic links"]
                     [(6) "you do not have permissions to delete file"]
                     [(7) "device is busy"]
-                    [(8) "IO error encountered while deleting"]
+                    [(8) "IO die encountered while deleting"]
                     [(9) "is in a read-only file system"]
-                    [(10) "internal access error while deleting"]
-                    [else "Unknown error while deleting"])
+                    [(10) "internal access die while deleting"]
+                    [else "Unknown die while deleting"])
                   x)]))))
 
   (define ($getenv-bv key)
@@ -104,7 +104,7 @@
   (define (getenv key)
     (if (string? key)
         ($getenv-str key)
-        (error 'getenv "the key is not a string" key)))
+        (die 'getenv "the key is not a string" key)))
 
   (define env
     (let ()
@@ -113,20 +113,20 @@
           [(key) 
            (if (string? key)
                (foreign-call "ikrt_getenv" key)
-               (error 'env "the key is not a string" key))]
+               (die 'env "the key is not a string" key))]
           [(key val) (env key val #t)]
           [(key val overwrite?)
            (if (string? key)
                (if (string? val)
                    (unless (foreign-call "ikrt_setenv" key val overwrite?)
-                     (error 'env "failed" key val))
-                   (error 'env "the value is not a string" val))
-               (error 'env "the key is not a string" key))]))
-      (define busted (lambda args (error 'env "BUG: busted!")))
+                     (die 'env "failed" key val))
+                   (die 'env "the value is not a string" val))
+               (die 'env "the key is not a string" key))]))
+      (define busted (lambda args (die 'env "BUG: busted!")))
       busted))
 
 
-  (define environ (lambda args (error 'environ "busted!")))
+  (define environ (lambda args (die 'environ "busted!")))
   (define environ^
     (lambda ()
       (map 
diff --git a/scheme/ikarus.predicates.ss b/scheme/ikarus.predicates.ss
index 390d92f..28cd478 100644
--- a/scheme/ikarus.predicates.ss
+++ b/scheme/ikarus.predicates.ss
@@ -121,7 +121,7 @@
         [(sys:ratnum? x) #t]
         [(sys:flonum? x) #f]
         [else 
-         (error 'exact? "not a number" x)])))
+         (die 'exact? "not a number" x)])))
   
 
   (define inexact?
@@ -132,7 +132,7 @@
         [(sys:bignum? x) #f]
         [(sys:ratnum? x) #f]
         [else 
-         (error 'inexact? "not a number" x)])))
+         (die 'inexact? "not a number" x)])))
 
   (define finite?
     (lambda (x)
@@ -142,7 +142,7 @@
         [(sys:bignum? x) #t]
         [(sys:ratnum? x) #t]
         [else 
-         (error 'finite? "not a number" x)])))
+         (die 'finite? "not a number" x)])))
 
   (define infinite?
     (lambda (x)
@@ -152,7 +152,7 @@
         [(sys:bignum? x) #f]
         [(sys:ratnum? x) #f]
         [else 
-         (error 'infinite? "not a number" x)])))
+         (die 'infinite? "not a number" x)])))
 
   (define nan?
     (lambda (x)
@@ -162,7 +162,7 @@
         [(sys:bignum? x) #f]
         [(sys:ratnum? x) #f]
         [else 
-         (error 'nan? "not a number" x)])))
+         (die 'nan? "not a number" x)])))
 
 
 
@@ -204,8 +204,8 @@
               #t
               (if (sys:boolean? y) 
                   #f
-                  (error 'boolean=? "not a boolean" y)))
-          (error 'boolean=? "not a boolean" x))))
+                  (die 'boolean=? "not a boolean" y)))
+          (die 'boolean=? "not a boolean" x))))
 
 
   (define symbol=?
@@ -215,8 +215,8 @@
               #t
               (if (sys:symbol? y) 
                   #f
-                  (error 'symbol=? "not a symbol" y)))
-          (error 'symbol=? "not a symbol" x))))
+                  (die 'symbol=? "not a symbol" y)))
+          (die 'symbol=? "not a symbol" x))))
 
   (module (equal?)
     (define vector-loop
diff --git a/scheme/ikarus.pretty-print.ss b/scheme/ikarus.pretty-print.ss
index bce2d42..3fabb81 100644
--- a/scheme/ikarus.pretty-print.ss
+++ b/scheme/ikarus.pretty-print.ss
@@ -31,7 +31,7 @@
     (make-parameter 60
       (lambda (x) 
         (unless (and (exact? x) (integer? x) (> x 0))
-          (error 'pretty-width "invalid argument" x))
+          (die 'pretty-width "invalid argument" x))
         x)))
   
   (define (pretty-indent) 1)
@@ -48,7 +48,7 @@
       [(mbox? x)   (mbox-length x)]
       [(vbox? x)   (vbox-length x)]
       [(fbox? x)   (fbox-length x)]
-      [else (error 'boxify "invalid box" x)]))
+      [else (die 'boxify "invalid box" x)]))
   (define (boxify x)
     (define (conc . a*)
       (let ([n 
@@ -459,7 +459,7 @@
         [(mbox? x)   (output-mbox x p col)]
         [(vbox? x)   (output-vbox x p col)]
         [(fbox? x)   (output-fbox x p col)]
-        [else (error 'pretty-print-output "invalid" x)]))
+        [else (die 'pretty-print-output "invalid" x)]))
     (f x p 0)
     (newline p))
   ;;;
@@ -608,7 +608,7 @@
       [(x p)
        (if (output-port? p)
            (pretty x p)
-           (error 'pretty-print "not an output port" p))]))
+           (die 'pretty-print "not an output port" p))]))
   ;;; standard formats
   (set-fmt! 'quote '(read-macro . "'"))
   (set-fmt! 'unquote '(read-macro . ","))
@@ -675,7 +675,7 @@
       [(x p)
        (if (output-port? p)
            (pretty x p)
-           (error 'pretty-print "not an output port" p))])))
+           (die 'pretty-print "not an output port" p))])))
 
 (test '(384 7384 83947 893478 9137489 3894789 134789314 79817238
         97314897 318947138974 981374 89137489 1374897 13498713
@@ -706,5 +706,5 @@
                      (with-input-from-file fname read))])
               (if (equal? x y)
                   (f (fxadd1 i))
-                  (error 'test-file "mismatch" x y)))))))))
+                  (die 'test-file "mismatch" x y)))))))))
 
diff --git a/scheme/ikarus.promises.ss b/scheme/ikarus.promises.ss
index 064be82..a404579 100644
--- a/scheme/ikarus.promises.ss
+++ b/scheme/ikarus.promises.ss
@@ -21,12 +21,12 @@
 
   (define (force x)
     (unless (procedure? x) 
-      (error 'force "not a procedure" x))
+      (die 'force "not a procedure" x))
     (x))
 
   (define (make-promise proc)
     (unless (procedure? proc)
-      (error 'make-promise "not a procedure" proc))
+      (die 'make-promise "not a procedure" proc))
     (let ([results #f])
       (lambda () 
         (if results
diff --git a/scheme/ikarus.reader.ss b/scheme/ikarus.reader.ss
index b6a39f7..57644c3 100644
--- a/scheme/ikarus.reader.ss
+++ b/scheme/ikarus.reader.ss
@@ -79,13 +79,13 @@
           (read-char p)
           (tokenize-backslash ls p)]
          [else
-          (error 'tokenize "invalid identifier syntax" 
+          (die 'tokenize "invalid identifier syntax" 
                  (list->string (reverse (cons c ls))))]))))
   (define (tokenize-string ls p)
     (let ([c (read-char p)])
       (cond
         [(eof-object? c) 
-         (error 'tokenize "invalid eof inside string")]
+         (die 'tokenize "invalid eof inside string")]
         [else (tokenize-string-char ls p c)])))
   (define (tokenize-string-char ls p c)
     (define (intraline-whitespace? c)
@@ -94,13 +94,13 @@
     (define (tokenize-string-continue ls p c)
       (cond
         [(eof-object? c) 
-         (error 'tokenize "invalid eof inside string")]
+         (die 'tokenize "invalid eof inside string")]
         [(intraline-whitespace? c)
          (let f ()
            (let ([c (read-char p)])
              (cond
                [(eof-object? c) 
-                (error 'tokenize "invalid eof inside string")]
+                (die 'tokenize "invalid eof inside string")]
                [(intraline-whitespace? c) (f)]
                [else (tokenize-string-char ls p c)])))]
         [else (tokenize-string-char ls p c)]))
@@ -110,7 +110,7 @@
       (let ([c (read-char p)])
         (cond
           [(eof-object? c) 
-           (error 'tokenize "invalid eof after string escape")]
+           (die 'tokenize "invalid eof after string escape")]
           [($char= #\a c) (tokenize-string (cons #\x7 ls) p)]
           [($char= #\b c) (tokenize-string (cons #\x8 ls) p)]
           [($char= #\t c) (tokenize-string (cons #\x9 ls) p)]
@@ -124,32 +124,32 @@
            (let ([c (read-char p)])
              (cond
                [(eof-object? c) 
-                (error 'tokenize "invalid eof inside string")]
+                (die 'tokenize "invalid eof inside string")]
                [(hex c) =>
                 (lambda (n)
                   (let f ([n n])
                     (let ([c (read-char p)])
                       (cond
                         [(eof-object? n) 
-                         (error 'tokenize "invalid eof inside string")]
+                         (die 'tokenize "invalid eof inside string")]
                         [(hex c) =>
                          (lambda (v) (f (+ (* n 16) v)))]
                         [($char= c #\;) 
                          (tokenize-string
                            (cons (integer->char n) ls) p)]
                         [else
-                         (error 'tokenize
+                         (die 'tokenize
                            "invalid char in escape sequence"
                            c)]))))]
                [else 
-                (error 'tokenize
+                (die 'tokenize
                   "invalid char in escape sequence" c)]))]
           [(intraline-whitespace? c)
            (let f ()
              (let ([c (read-char p)])
                (cond
                  [(eof-object? c) 
-                  (error 'tokenize "invalid eof inside string")]
+                  (die 'tokenize "invalid eof inside string")]
                  [(intraline-whitespace? c) (f)]
                  [(memv c '(#\xA #\x85 #\x2028)) 
                   (tokenize-string-continue ls p (read-char p))]
@@ -161,7 +161,7 @@
                       [else 
                        (tokenize-string-continue ls p c)]))]
                  [else
-                  (error 'tokenize 
+                  (die 'tokenize 
                     "non-whitespace character after escape")])))]
           [(memv c '(#\xA #\x85 #\x2028))
            (tokenize-string-continue ls p (read-char p))]
@@ -172,7 +172,7 @@
                 (tokenize-string-continue ls p (read-char p))]
                [else 
                 (tokenize-string-continue ls p c)]))]
-          [else (error 'tokenize "invalid string escape" c)]))]
+          [else (die 'tokenize "invalid string escape" c)]))]
      [(memv c '(#\xA #\x85 #\x2028))
       (tokenize-string (cons #\linefeed ls) p)]
      [(memv c '(#\xD))
@@ -200,7 +200,7 @@
            (let ([c (peek-char p)])
              (cond
                [(eof-object? c) 
-                (error 'tokenize "invalid syntax .. near end of file")]
+                (die 'tokenize "invalid syntax .. near end of file")]
                [($char= c #\.) ; this is the third
                 (read-char p)
                 (let ([c (peek-char p)])
@@ -208,10 +208,10 @@
                     [(eof-object? c) '(datum . ...)]
                     [(delimiter? c)  '(datum . ...)]
                     [else 
-                     (error 'tokenize "invalid syntax"
+                     (die 'tokenize "invalid syntax"
                             (string-append "..." (string c)))]))]
                [else
-                (error 'tokenize "invalid syntax"
+                (die 'tokenize "invalid syntax"
                        (string-append ".." (string c)))]))]
           [else 
            (cons 'datum 
@@ -224,17 +224,17 @@
           (cond
            [(eof-object? c) d]
            [(delimiter? c)  d]
-           [else (error 'tokenize "invalid character after sequence"
+           [else (die 'tokenize "invalid character after sequence"
                         (string-append (string c) str))]))]
        [else
         (let ([c (read-char p)])
           (cond
             [(eof-object? c) 
-             (error 'tokenize "invalid eof in the middle of expected sequence" str)]
+             (die 'tokenize "invalid eof in the middle of expected sequence" str)]
             [($char= c (string-ref str i))
              (tokenize-char* (fxadd1 i) str p d)]
             [else 
-             (error 'tokenize
+             (die 'tokenize
                     "invalid char while scanning string"
                     c str)]))])))
   (define tokenize-char-seq
@@ -246,14 +246,14 @@
           [($char= (string-ref str 1) c) 
            (read-char p)
            (tokenize-char*  2 str p d)]
-          [else (error 'tokenize "invalid syntax" 
+          [else (die 'tokenize "invalid syntax" 
                        (string-ref str 0) c)]))))
   (define tokenize-char
     (lambda (p)
       (let ([c (read-char p)])
         (cond
           [(eof-object? c)
-           (error 'tokenize "invalid #\\ near end of file")]
+           (die 'tokenize "invalid #\\ near end of file")]
           [(eqv? #\n c) 
            (let ([c (peek-char p)])
              (cond
@@ -269,7 +269,7 @@
                [(delimiter? c)
                 '(datum . #\n)]
                [else 
-                (error 'tokenize "invalid syntax"
+                (die 'tokenize "invalid syntax"
                   (string #\# #\\ #\n c))]))]
           [(eqv? #\a c) 
            (tokenize-char-seq p "alarm" '(datum . #\x7))]
@@ -311,9 +311,9 @@
                            (read-char p)
                            (f (+ (* v 16) v0)))]
                         [else
-                         (error 'tokenize "invalid character sequence")]))))]
+                         (die 'tokenize "invalid character sequence")]))))]
                [else
-                (error 'tokenize "invalid character sequence"
+                (die 'tokenize "invalid character sequence"
                        (string-append "#\\" (string n)))]))]
           [else
            (let ([n (peek-char p)])
@@ -321,7 +321,7 @@
                [(eof-object? n) (cons 'datum c)]
                [(delimiter? n)  (cons 'datum c)]
                [else 
-                (error 'tokenize "invalid syntax"
+                (die 'tokenize "invalid syntax"
                        (string-append "#\\" (string c n)))]))]))))
   (define (hex x)
     (cond
@@ -336,7 +336,7 @@
       [else #f]))
   (define multiline-error
     (lambda ()
-      (error 'tokenize
+      (die 'tokenize
              "end of file encountered while inside a #|-style comment")))
   (define apprev
     (lambda (str i ac)
@@ -379,27 +379,27 @@
     (let ([c (read-char p)])
       (cond
         [(eof-object? c)
-         (error 'tokenize "invalid eof inside" caller)]
+         (die 'tokenize "invalid eof inside" caller)]
         [(char-whitespace? c)
          (skip-whitespace p caller)]
         [else c])))
   (define tokenize-hash/c
     (lambda (c p)
       (cond
-        [(eof-object? c) (error 'tokenize "invalid # near end of file")]
+        [(eof-object? c) (die 'tokenize "invalid # near end of file")]
         [(memq c '(#\t #\T)) 
          (let ([c (peek-char p)])
            (cond
              [(eof-object? c) '(datum . #t)]
              [(delimiter? c)  '(datum . #t)]
-             [else (error 'tokenize 
+             [else (die 'tokenize 
                      (format "invalid syntax near #~a" c))]))]
         [(memq c '(#\f #\F)) 
          (let ([c (peek-char p)])
            (cond
              [(eof-object? c) '(datum . #f)]
              [(delimiter? c)  '(datum . #f)]
-             [else (error 'tokenize 
+             [else (die 'tokenize 
                      (format "invalid syntax near #~a" c))]))]
         [($char= #\\ c) (tokenize-char p)]
         [($char= #\( c) 'vparen]
@@ -417,11 +417,11 @@
         [($char= #\! c) 
          (let ([e (read-char p)])
            (when (eof-object? e)
-             (error 'tokenize "invalid eof near #!"))
+             (die 'tokenize "invalid eof near #!"))
            (case e
              [(#\e) 
               (when (eq? (port-mode p) 'r6rs-mode)
-                (error 'tokenize "invalid syntax: #!e"))
+                (die 'tokenize "invalid syntax: #!e"))
               (read-char* p '(#\e) "of" "eof sequence" #f #f)
               (cons 'datum (eof-object))]
              [(#\r) 
@@ -433,16 +433,16 @@
               (set-port-mode! p 'ikarus-mode)
               (tokenize p)]
              [else
-              (error 'tokenize
+              (die 'tokenize
                 (format "invalid syntax near #!~a" e))]))]
         [(digit? c) 
          (when (eq? (port-mode p) 'r6rs-mode)
-           (error 'tokenize "graph syntax is invalid in #!r6rs mode"
+           (die 'tokenize "graph syntax is invalid in #!r6rs mode"
               (format "#~a" c)))
          (tokenize-hashnum p (char->num c))]
         [($char= #\: c)
          (when (eq? (port-mode p) 'r6rs-mode)
-           (error 'tokenize "gensym syntax is invalid in #!r6rs mode"
+           (die 'tokenize "gensym syntax is invalid in #!r6rs mode"
               (format "#~a" c)))
          (let* ([c (skip-whitespace p "gensym")]
                 [id0 
@@ -454,12 +454,12 @@
                     (list->string 
                       (reverse (tokenize-bar p '())))]
                    [else 
-                    (error 'tokenize
+                    (die 'tokenize
                       "invalid char inside gensym" c)])])
               (cons 'datum (gensym id0)))]
         [($char= #\{ c)
          (when (eq? (port-mode p) 'r6rs-mode)
-           (error 'tokenize "gensym syntax is invalid in #!r6rs mode"
+           (die 'tokenize "gensym syntax is invalid in #!r6rs mode"
               (format "#~a" c)))
          (let* ([c (skip-whitespace p "gensym")]
                 [id0 
@@ -471,7 +471,7 @@
                     (list->string 
                       (reverse (tokenize-bar p '())))]
                    [else 
-                    (error 'tokenize
+                    (die 'tokenize
                       "invalid char inside gensym" c)])]
                 [c (skip-whitespace p "gensym")])
            (cond
@@ -491,7 +491,7 @@
                         (list->string 
                           (reverse (tokenize-bar p '())))]
                        [else 
-                        (error 'tokenize
+                        (die 'tokenize
                           "invalid char inside gensym" c)])])
                 (let ([c (skip-whitespace p "gensym")])
                   (cond
@@ -500,7 +500,7 @@
                       (foreign-call "ikrt_strings_to_gensym" 
                         id0 id1))]
                     [else
-                     (error 'tokenize
+                     (die 'tokenize
                         "invalid char inside gensym" c)])))]))]
         [($char= #\v c)
          (let ([c (read-char p)])
@@ -513,16 +513,16 @@
                      (cond
                        [($char= c #\() 'vu8]
                        [(eof-object? c) 
-                        (error 'tokenize "invalid eof object after #vu8")]
-                       [else (error 'tokenize 
+                        (die 'tokenize "invalid eof object after #vu8")]
+                       [else (die 'tokenize 
                                (format "invalid sequence #vu8~a" c))]))]
                   [(eof-object? c) 
-                   (error 'tokenize "invalid eof object after #vu")]
-                  [else (error 'tokenize 
+                   (die 'tokenize "invalid eof object after #vu")]
+                  [else (die 'tokenize 
                            (format "invalid sequence #vu~a" c))]))]
              [(eof-object? c) 
-              (error 'tokenize "invalid eof object after #v")]
-             [else (error 'tokenize
+              (die 'tokenize "invalid eof object after #v")]
+             [else (die 'tokenize
                      (format "invalid sequence #v~a" c))]))]
         [(memq c '(#\e #\E)) 
          (cons 'datum (tokenize-exactness-mark p (list c #\#) 'e))]
@@ -538,12 +538,12 @@
          (cons 'datum (tokenize-radix-mark p (list c #\#) 10))]
         [($char= #\@ c)
          (when (eq? (port-mode p) 'r6rs-mode)
-           (error 'tokenize "fasl syntax is invalid in #!r6rs mode"
+           (die 'tokenize "fasl syntax is invalid in #!r6rs mode"
               (format "#~a" c)))
-         (error 'read "FIXME: fasl read disabled")
+         (die 'read "FIXME: fasl read disabled")
          '(cons 'datum ($fasl-read p))]
         [else 
-         (error 'tokenize 
+         (die 'tokenize 
             (format "invalid syntax #~a" c))])))
   (define (tokenize-exactness-mark p ls exact?)
     (let ([c (read-char p)])
@@ -771,7 +771,7 @@
          [(#\0) 0]
          [(#\1) 1]
          [else #f])]
-      [else (error 'radix-digit "invalid radix" radix)]))
+      [else (die 'radix-digit "invalid radix" radix)]))
   (define (read-char* p ls str who ci? delimited?)
     (let f ([i 0] [ls ls])
       (cond
@@ -779,20 +779,20 @@
          (when delimited?
            (let ([c (peek-char p)])
              (when (and (not (eof-object? c)) (not (delimiter? c)))
-               (error 'tokenize 
+               (die 'tokenize 
                  (format "invalid ~a: ~s" who 
                    (list->string (reverse (cons c ls))))))))]
         [else
          (let ([c (read-char p)])
            (cond
              [(eof-object? c) 
-              (error 'tokenize
+              (die 'tokenize
                 (format "invalid eof inside ~a" who))]
              [(or (and (not ci?) (char=? c (string-ref str i)))
                   (and ci? (char=? (char-downcase c) (string-ref str i))))
               (f (add1 i) (cons c ls))]
              [else 
-              (error 'tokenize 
+              (die 'tokenize 
                 (format "invalid ~a: ~s" who
                   (list->string (reverse (cons c ls)))))]))])))
   (define (tokenize-integer/nan/inf-no-digits p ls)
@@ -824,30 +824,30 @@
          (tokenize-decimal-no-digits p (cons c ls) exact?)]
         [else (num-error "invalid sequence" (cons c ls))])))
   (define (num-error str ls)
-    (error 'read "invalid numeric sequence"
+    (die 'read "invalid numeric sequence"
       (list->string (reverse ls))))
   (define (tokenize-hashnum p n)
     (let ([c (read-char p)])
       (cond
         [(eof-object? c) 
-         (error 'tokenize "invalid eof inside #n mark/ref")]
+         (die 'tokenize "invalid eof inside #n mark/ref")]
         [($char= #\= c) (cons 'mark n)]
         [($char= #\# c) (cons 'ref n)]
         [(digit? c)
          (tokenize-hashnum p (fx+ (fx* n 10) (char->num c)))]
         [else
-         (error 'tokenize "invalid char while inside a #n mark/ref" c)])))
+         (die 'tokenize "invalid char while inside a #n mark/ref" c)])))
   (define tokenize-bar
     (lambda (p ac)
       (let ([c (read-char p)])
         (cond
           [(eof-object? c) 
-           (error 'tokenize "unexpected eof while reading symbol")]
+           (die 'tokenize "unexpected eof while reading symbol")]
           [($char= #\\ c)
            (let ([c (read-char p)])
              (cond
                [(eof-object? c) 
-                (error 'tokenize "unexpected eof while reading symbol")]
+                (die 'tokenize "unexpected eof while reading symbol")]
                [else (tokenize-bar p (cons c ac))]))]
           [($char= #\| c) ac]
           [else (tokenize-bar p (cons c ac))]))))
@@ -855,19 +855,19 @@
     (let ([c (read-char p)])
       (cond
         [(eof-object? c) 
-         (error 'tokenize "invalid eof after symbol escape")]
+         (die 'tokenize "invalid eof after symbol escape")]
         [($char= #\x c) 
          (let ([c (read-char p)])
            (cond
              [(eof-object? c) 
-              (error 'tokenize "invalid eof after \\x")]
+              (die 'tokenize "invalid eof after \\x")]
              [(hex c) => 
               (lambda (v)
                 (let f ([v v] [ac `(,c #\x #\\)])
                   (let ([c (read-char p)])
                     (cond
                       [(eof-object? c) 
-                       (error 'tokenize 
+                       (die 'tokenize 
                          (format "invalid eof after ~a"
                            (list->string (reverse ac))))]
                       [($char= #\; c)
@@ -876,13 +876,13 @@
                        (lambda (v0)
                          (f (+ (* v 16) v0) (cons c ac)))]
                       [else 
-                       (error 'tokenize "invalid sequence"
+                       (die 'tokenize "invalid sequence"
                          (list->string (cons c (reverse ac))))]))))]
              [else
-              (error 'tokenize 
+              (die 'tokenize 
                  (format "invalid sequence \\x~a" c))]))]
         [else 
-         (error 'tokenize
+         (die 'tokenize
            (format "invalid sequence \\~a" c))])))
   (define tokenize/c
     (lambda (c p)
@@ -942,7 +942,7 @@
          (tokenize-dot p)]
         [($char= #\| c)
          (when (eq? (port-mode p) 'r6rs-mode)
-           (error 'tokenize "|symbol| syntax is invalid in #!r6rs mode"))
+           (die 'tokenize "|symbol| syntax is invalid in #!r6rs mode"))
          (let ([ls (reverse (tokenize-bar p '()))])
            (cons 'datum (string->symbol (list->string ls))))]
         [($char= #\\ c)
@@ -951,7 +951,7 @@
               (list->string
                 (reverse (tokenize-backslash '() p)))))]
         [else
-         (error 'tokenize "invalid syntax" c)])))
+         (die 'tokenize "invalid syntax" c)])))
 
   (define tokenize
     (lambda (p)
@@ -966,7 +966,7 @@
            (let ([c (read-char p)])
              (cond
                [(eof-object? c)
-                (error 'tokenize "invalid eof after #")]
+                (die 'tokenize "invalid eof after #")]
                [($char= #\! c)
                 (skip-comment p)
                 (tokenize p)]
@@ -979,21 +979,21 @@
       (let ([t (tokenize p)])
         (cond
          [(eof-object? t)
-          (error 'read "end of file encountered while reading list")]
+          (die 'read "end of file encountered while reading list")]
          [(eq? t end) (values '() locs k)]
          [(eq? t mis) 
-          (error 'read "paren mismatch")]
+          (die 'read "paren mismatch")]
          [(eq? t 'dot)
           (let-values ([(d locs k) (read-expr p locs k)])
             (let ([t (tokenize p)])
               (cond
                [(eq? t end) (values d locs k)]
                [(eq? t mis)
-                (error 'read "paren mismatch")]
+                (die 'read "paren mismatch")]
                [(eq? t 'dot)
-                (error 'read "cannot have two dots in a list")]
+                (die 'read "cannot have two dots in a list")]
                [else
-                (error 'read 
+                (die 'read 
                   (format "expecting ~a, got ~a" end t))])))]
          [(eq? t 'hash-semi)
           (let-values ([(ignored locs k) (read-expr p locs k)])
@@ -1011,12 +1011,12 @@
       (let ([t (tokenize p)])
        (cond
          [(eof-object? t)
-          (error 'read "end of file encountered while reading list")]
+          (die 'read "end of file encountered while reading list")]
          [(eq? t end) (values '() locs k)]
          [(eq? t mis) 
-          (error 'read "paren mismatch")]
+          (die 'read "paren mismatch")]
          [(eq? t 'dot)
-          (error 'read "invalid dot while reading list")]
+          (die 'read "invalid dot while reading list")]
          [(eq? t 'hash-semi)
           (let-values ([(ignored locs k) (read-expr p locs k)])
             (read-list-init p locs k end mis))]
@@ -1061,25 +1061,25 @@
            (cond
              [(fixnum? a)
               (unless (and (fx<= 0 a) (fx<= a 255))
-                (error 'read 
+                (die 'read 
                   (format "invalid value ~s in a bytevector" a)))
               ($bytevector-set! v i a)
               (bytevector-put v k ($fxsub1 i) ($cdr ls))]
-             [else (error 'read "invalid value inside a bytevector" a)]))])))
+             [else (die 'read "invalid value inside a bytevector" a)]))])))
   (define read-vector
     (lambda (p locs k count ls)
       (let ([t (tokenize p)])
         (cond
           [(eof-object? t) 
-           (error 'read "end of file encountered while reading a vector")]
+           (die 'read "end of file encountered while reading a vector")]
           [(eq? t 'rparen) 
            (let ([v (make-vector count)])
              (let ([k (vector-put v k (fxsub1 count) ls)])
                (values v locs k)))]
           [(eq? t 'rbrack)
-           (error 'read "unexpected ] while reading a vector")]
+           (die 'read "unexpected ] while reading a vector")]
           [(eq? t 'dot)
-           (error 'read "unexpected . while reading a vector")]
+           (die 'read "unexpected . while reading a vector")]
           [(eq? t 'hash-semi)
            (let-values ([(ignored locs k) (read-expr p locs k)])
              (read-vector p locs k count ls))]
@@ -1091,15 +1091,15 @@
       (let ([t (tokenize p)])
         (cond
           [(eof-object? t) 
-           (error 'read "end of file encountered while reading a bytevector")]
+           (die 'read "end of file encountered while reading a bytevector")]
           [(eq? t 'rparen) 
            (let ([v ($make-bytevector count)])
              (let ([k (bytevector-put v k (fxsub1 count) ls)])
                (values v locs k)))]
           [(eq? t 'rbrack)
-           (error 'read "unexpected ] while reading a bytevector")]
+           (die 'read "unexpected ] while reading a bytevector")]
           [(eq? t 'dot)
-           (error 'read "unexpected . while reading a bytevector")]
+           (die 'read "unexpected . while reading a bytevector")]
           [(eq? t 'hash-semi)
            (let-values ([(ignored locs k) (read-expr p locs k)])
              (read-bytevector p locs k count ls))]
@@ -1124,7 +1124,7 @@
            [(eq? (car t) 'macro)
             (let-values ([(expr locs k) (read-expr p locs k)])
               (when (eof-object? expr) 
-                (error 'read 
+                (die 'read 
                   (format "invalid eof after ~a read macro"
                           (cdr t))))
               (let ([x (list expr)])
@@ -1142,7 +1142,7 @@
                    (lambda (x)
                      (let ([loc (cdr x)])
                        (when (loc-set? loc)
-                         (error 'read "duplicate mark" n))
+                         (die 'read "duplicate mark" n))
                        (set-loc-value! loc expr)
                        (set-loc-set?! loc #t)
                        (values expr locs k)))]
@@ -1160,9 +1160,9 @@
                  (let ([loc (make-loc #f #f)])
                    (let ([locs (cons (cons n loc) locs)])
                      (values loc locs k)))]))]
-           [else (error 'read "invalid token" t)])]
+           [else (die 'read "invalid token" t)])]
         [else
-         (error 'read 
+         (die 'read 
            (format "unexpected ~s found" t))])))
 
   (define read-expr
@@ -1177,7 +1177,7 @@
     (lambda (x)
        (let ([loc (cdr x)])
          (unless (loc-set? loc)
-           (error 'read "referenced mark is not set" (car x)))
+           (die 'read "referenced mark is not set" (car x)))
          (when (loc? (loc-value loc))
            (let f ([h loc] [t loc])
              (if (loc? h)
@@ -1185,7 +1185,7 @@
                    (if (loc? h1)
                        (begin
                          (when (eq? h1 t)
-                           (error 'read "circular marks"))
+                           (die 'read "circular marks"))
                          (let ([v (f (loc-value h1) (loc-value t))])
                            (set-loc-value! h1 v)
                            (set-loc-value! h v)
@@ -1225,7 +1225,7 @@
       [(p)
        (if (input-port? p)
            (tokenize p)
-           (error 'read-token "not an input port" p))]))
+           (die 'read-token "not an input port" p))]))
 
   (define read
     (case-lambda
@@ -1233,11 +1233,11 @@
       [(p)
        (if (input-port? p)
            (my-read p)
-           (error 'read "not an input port" p))]))
+           (die 'read "not an input port" p))]))
 
   (define (get-datum p)
     (unless (input-port? p) 
-      (error 'get-datum "not an input port"))
+      (die 'get-datum "not an input port"))
     (my-read p))
 
   (define comment-handler
@@ -1245,7 +1245,7 @@
       (lambda (x) (void))
       (lambda (x)
         (unless (procedure? x)
-          (error 'comment-handler "not a procedure" x))
+          (die 'comment-handler "not a procedure" x))
         x)))
 
   )
diff --git a/scheme/ikarus.records.procedural.ss b/scheme/ikarus.records.procedural.ss
index 3aeb822..c66b824 100644
--- a/scheme/ikarus.records.procedural.ss
+++ b/scheme/ikarus.records.procedural.ss
@@ -59,39 +59,39 @@
           (if (rtd? rtd)
               (if (not (rtd-opaque? rtd))
                   rtd
-                  (error 'record-rtd "record is opaque"))
-              (error 'record-rtd "not a record" x)))
-        (error 'record-rtd "not a record" x)))
+                  (die 'record-rtd "record is opaque"))
+              (die 'record-rtd "not a record" x)))
+        (die 'record-rtd "not a record" x)))
 
   (define (record-type-name x)
     (if (rtd? x)
         (rtd-name x)
-        (error 'record-type-name "not an rtd" x)))
+        (die 'record-type-name "not an rtd" x)))
 
   (define (record-type-parent x)
     (if (rtd? x)
         (rtd-parent x)
-        (error 'record-type-parent "not an rtd" x)))
+        (die 'record-type-parent "not an rtd" x)))
 
   (define (record-type-uid x)
     (if (rtd? x)
         (rtd-uid x)
-        (error 'record-type-uid "not an rtd" x)))
+        (die 'record-type-uid "not an rtd" x)))
 
   (define (record-type-sealed? x)
     (if (rtd? x)
         (rtd-sealed? x)
-        (error 'record-type-sealed? "not an rtd" x)))
+        (die 'record-type-sealed? "not an rtd" x)))
 
   (define (record-type-opaque? x)
     (if (rtd? x)
         (rtd-opaque? x)
-        (error 'record-type-opaque? "not an rtd" x)))
+        (die 'record-type-opaque? "not an rtd" x)))
 
   (define (record-type-generative? x)
     (if (rtd? x)
         (not (rtd-sealed? x))
-        (error 'record-type-generative? "not an rtd" x)))
+        (die 'record-type-generative? "not an rtd" x)))
 
   (define (record-type-field-names x)
     (if (rtd? x)
@@ -103,7 +103,7 @@
                   (begin
                     (vector-set! x i (cdr (vector-ref v i)))
                     (f x v n (fxadd1 i)))))))
-        (error 'record-type-field-names "not an rtd" x)))
+        (die 'record-type-field-names "not an rtd" x)))
 
 
   (module (make-record-type-descriptor)
@@ -114,7 +114,7 @@
           #f #f #f parent sealed? opaque? uid fields))
     (define (convert-fields sv)
       (unless (vector? sv) 
-        (error who "invalid fields argument" sv))
+        (die who "invalid fields argument" sv))
       (let ([n2 (vector-length sv)])
         (let ([v (make-vector n2)])
           (let f ([i 0])
@@ -125,16 +125,16 @@
                       (if (pair? x) 
                           (let ([name (car x)])
                             (unless (and (null? (cdr x)) (symbol? name))
-                              (error who "invalid fields argument" sv))
+                              (die who "invalid fields argument" sv))
                             (vector-set! v i
                               (cons (case m/u
                                       [(mutable)   #t]
                                       [(immutable) #f]
                                       [else 
-                                       (error who "invalid fields argument" sv)]) 
+                                       (die who "invalid fields argument" sv)]) 
                                     name)))
-                          (error who "invalid fields argument" sv)))
-                    (error who "invalid fields argument" sv)))
+                          (die who "invalid fields argument" sv)))
+                    (die who "invalid fields argument" sv)))
               (f (add1 i))))
           v)))
     (define generate-rtd
@@ -142,7 +142,7 @@
         (cond
           [(rtd? parent)
            (when (rtd-sealed? parent) 
-             (error who "cannot extend sealed parent" parent))
+             (die who "cannot extend sealed parent" parent))
            (make-rtd-aux name parent uid sealed? 
              (or opaque? (rtd-opaque? parent))
              (rtd-size parent)
@@ -150,7 +150,7 @@
           [(eqv? parent #f) 
            (make-rtd-aux name parent uid sealed? opaque? 0
              (convert-fields fields))]
-          [else (error who "not a valid parent" parent)])))
+          [else (die who "not a valid parent" parent)])))
     (define (same-fields-as-rtd? fields rtd)
       (let* ([fv (rtd-fields rtd)]
              [n (vector-length fv)])
@@ -183,7 +183,7 @@
                     (eqv? sealed? (rtd-sealed? rtd))
                     (eqv? opaque? (rtd-opaque? rtd))
                     (same-fields-as-rtd? fields rtd))
-               (error who "invalid arguments"))
+               (die who "invalid arguments"))
              rtd)]
           [else
            (let ([rtd (generate-rtd name parent uid sealed? opaque? fields)])
@@ -192,17 +192,17 @@
     (define make-record-type-descriptor
       (lambda (name parent uid sealed? opaque? fields)
         (unless (symbol? name)
-          (error who "not a valid record type name" name))
+          (die who "not a valid record type name" name))
         (unless (boolean? sealed?)
-          (error who "not a valid sealed? argument" sealed?))
+          (die who "not a valid sealed? argument" sealed?))
         (unless (boolean? opaque?)
-          (error who "not a valid opaque? argument" opaque?))
+          (die who "not a valid opaque? argument" opaque?))
         (cond
           [(symbol? uid) 
            (make-nongenerative-rtd name parent uid sealed? opaque? fields)]
           [(eqv? uid #f) 
            (generate-rtd name parent uid sealed? opaque? fields)]
-          [else (error who "not a valid uid" uid)]))))
+          [else (die who "not a valid uid" uid)]))))
 
   (define-struct rcd (rtd prcd proc))
 
@@ -215,9 +215,9 @@
 
   (define (rtd-subtype? rtd parent-rtd) 
     (unless (rtd? rtd) 
-      (error 'rtd-subtype? "not an rtd" rtd))
+      (die 'rtd-subtype? "not an rtd" rtd))
     (unless (rtd? parent-rtd) 
-      (error 'rtd-substype? "not an rtd" parent-rtd))
+      (die 'rtd-substype? "not an rtd" parent-rtd))
     (or (eq? rtd parent-rtd)
         (is-parent-of? parent-rtd rtd)))
         
@@ -225,20 +225,20 @@
     (lambda (rtd prcd protocol)
       (define who 'make-record-constructor-descriptor)
       (unless (rtd? rtd)
-        (error who "not a record type descriptor" rtd))
+        (die who "not a record type descriptor" rtd))
       (unless (or (not protocol) (procedure? protocol))
-        (error who "invalid protocol" protocol))
+        (die who "invalid protocol" protocol))
       (let ([prtd (rtd-parent rtd)])
         (cond
           [(not prcd) 
            (make-rcd rtd #f protocol)]
           [(rcd? prcd) 
            (unless (is-parent-of? (rcd-rtd prcd) rtd)
-             (error who "descriptor does not apply" 
+             (die who "descriptor does not apply" 
                     prcd rtd))
            (make-rcd rtd prcd protocol)]
           [else
-           (error who "not a valid record constructor descriptor" prcd)]))))
+           (die who "not a valid record constructor descriptor" prcd)]))))
 
   (define (record-constructor rcd)
     (define who 'record-constructor)
@@ -250,7 +250,7 @@
             (if (pair? ls) 
                 (let-values ([(m p) (f (cdr ls) (- n 1))]) 
                   (values (cons (car ls) m) p))
-                (error 'record-condtructor "insufficient arguments"
+                (die 'record-condtructor "insufficient arguments"
                        all-fields)))))
 
     (define (constructor main-rtd size prcd proto)
@@ -260,7 +260,7 @@
                    (lambda flds
                       (let ([n (rtd-size main-rtd)])
                         (unless (= (length flds) size)
-                          (apply error
+                          (apply die
                              'a-record-constructor
                              (format 
                                "expected ~a args, got ~a instead" 
@@ -301,7 +301,7 @@
                   (lambda fmls
                     (lambda flds
                       (unless (= (length flds) n) 
-                        (apply error
+                        (apply die
                            'a-record-constructor
                            (format 
                              "expected ~a args, got ~a instead" 
@@ -309,7 +309,7 @@
                            flds))
                       (apply (p (cons flds f*)) fmls)))))))))
     (unless (rcd? rcd)
-      (error who "not a record constructor descriptor" rcd))
+      (die who "not a record constructor descriptor" rcd))
     (let ([rtd (rcd-rtd rcd)]
           [prcd (rcd-prcd rcd)]
           [proto (rcd-proc rcd)])
@@ -319,14 +319,14 @@
   (define (record-accessor rtd k) 
     (define who 'record-accessor)
     (unless (rtd? rtd)
-      (error who "not an rtd" rtd))
+      (die who "not an rtd" rtd))
     (unless (and (fixnum? k) (fx>= k 0)) 
-      (error who "not a valid index" k))
+      (die who "not a valid index" k))
     (let ([sz (rtd-size rtd)]
           [p (rtd-parent rtd)])
       (let ([i (if p (+ k (rtd-size p)) k)])
         (unless (fx< i sz) 
-          (error who "not a valid index" k))
+          (die who "not a valid index" k))
         (let ([a-record-accessor
                (lambda (x) 
                  (cond
@@ -334,29 +334,29 @@
                    [($struct? x)
                     (let ([xrtd ($struct-rtd x)])
                       (unless (rtd? xrtd) 
-                        (error who "invalid type" x rtd))
+                        (die who "invalid type" x rtd))
                       (let f ([prtd (rtd-parent xrtd)] [rtd rtd] [x x] [i i])
                         (cond
                           [(eq? prtd rtd) ($struct-ref x i)]
                           [(not prtd) 
-                           (error who "invalid type" x rtd)]
+                           (die who "invalid type" x rtd)]
                           [else (f (rtd-parent prtd) rtd x i)])))]
-                   [else (error who "invalid type" x rtd)]))])
+                   [else (die who "invalid type" x rtd)]))])
           a-record-accessor))))
 
   (define (record-mutator rtd k) 
     (define who 'record-mutator)
     (unless (rtd? rtd)
-      (error who "not an rtd" rtd))
+      (die who "not an rtd" rtd))
     (unless (and (fixnum? k) (fx>= k 0)) 
-      (error who "not a valid index" k))
+      (die who "not a valid index" k))
     (let ([sz (rtd-size rtd)]
           [p (rtd-parent rtd)])
       (let ([i (if p (+ k (rtd-size p)) k)])
         (unless (fx< i sz) 
-          (error who "not a valid index" k))
+          (die who "not a valid index" k))
         (unless (car (vector-ref (rtd-fields rtd) k))
-          (error who "field is not mutable" k rtd))
+          (die who "field is not mutable" k rtd))
         (let ([a-record-mutator
                (lambda (x v) 
                  (cond
@@ -364,20 +364,20 @@
                    [($struct? x)
                     (let ([xrtd ($struct-rtd x)])
                       (unless (rtd? xrtd) 
-                        (error who "invalid type" x rtd))
+                        (die who "invalid type" x rtd))
                       (let f ([prtd (rtd-parent xrtd)] [rtd rtd] [x x] [i i] [v v])
                         (cond
                           [(eq? prtd rtd) ($struct-set! x i v)]
                           [(not prtd) 
-                           (error who "invalid type" x rtd)]
+                           (die who "invalid type" x rtd)]
                           [else (f (rtd-parent prtd) rtd x i v)])))]
-                   [else (error who "invalid type" x rtd)]))])
+                   [else (die who "invalid type" x rtd)]))])
           a-record-mutator))))
 
   (define (record-predicate rtd) 
     (define who 'record-predicate)
     (unless (rtd? rtd)
-      (error who "not an rtd" rtd))
+      (die who "not an rtd" rtd))
     (let ([sz (rtd-size rtd)]
           [p (rtd-parent rtd)])
       (let ([a-record-predicate
@@ -399,14 +399,14 @@
   (define (record-field-mutable? rtd k) 
     (define who 'record-field-mutable?)
     (unless (rtd? rtd)
-      (error who "not an rtd" rtd))
+      (die who "not an rtd" rtd))
     (unless (and (fixnum? k) (fx>= k 0)) 
-      (error who "not a valid index" k))
+      (die who "not a valid index" k))
     (let ([sz (rtd-size rtd)]
           [p (rtd-parent rtd)])
       (let ([i (if p (+ k (rtd-size p)) k)])
         (unless (fx< i sz) 
-          (error who "not a valid index" k))
+          (die who "not a valid index" k))
         (car (vector-ref (rtd-fields rtd) k)))))
 
   (set-rtd-printer! (type-descriptor rtd)
diff --git a/scheme/ikarus.sort.ss b/scheme/ikarus.sort.ss
index 0535442..d225dd2 100644
--- a/scheme/ikarus.sort.ss
+++ b/scheme/ikarus.sort.ss
@@ -77,7 +77,7 @@
 
   (define (list-sort <? ls) 
     (unless (procedure? <?)
-      (error 'list-sort "not a procedure" <?))
+      (die 'list-sort "not a procedure" <?))
     (sort-tail <? ls (length ls)))
 
 
@@ -85,9 +85,9 @@
   (define (vector-sort <? v)
     ;;; FIXME: improve
     (unless (procedure? <?)
-      (error 'vector-sort "not a procedure" <?))
+      (die 'vector-sort "not a procedure" <?))
     (unless (vector? v)
-      (error 'vector-sort "not a vector" v))
+      (die 'vector-sort "not a vector" v))
     (list->vector 
       (sort-tail <? (vector->list v) (vector-length v))))
 
@@ -95,9 +95,9 @@
     (import (ikarus system $vectors))
     (import (ikarus system $pairs))
     (unless (procedure? <?)
-      (error 'vector-sort! "not a procedure" <?))
+      (die 'vector-sort! "not a procedure" <?))
     (unless (vector? v)
-      (error 'vector-sort! "not a vector" v))
+      (die 'vector-sort! "not a vector" v))
     (let f ([i 0] [v v] 
             [ls (sort-tail <? (vector->list v) (vector-length v))])
       (unless (null? ls) 
diff --git a/scheme/ikarus.strings.ss b/scheme/ikarus.strings.ss
index 6ad883d..8c2738f 100644
--- a/scheme/ikarus.strings.ss
+++ b/scheme/ikarus.strings.ss
@@ -36,35 +36,35 @@
   (define string-length
     (lambda (x)
       (unless (string? x)
-        (error 'string-length "not a string" x))
+        (die 'string-length "not a string" x))
       ($string-length x)))
 
 
   (define (string-ref s i)
     (unless (string? s) 
-      (error 'string-ref "not a string" s))
+      (die 'string-ref "not a string" s))
     (unless (fixnum? i)
-      (error 'string-ref "not a valid index" i))
+      (die 'string-ref "not a valid index" i))
     (unless (and ($fx< i ($string-length s))
                  ($fx<= 0 i))
-      (error 'string-ref "index is out of range" i s))
+      (die 'string-ref "index is out of range" i s))
     (let ([c ($string-ref s i)])
       (unless (char? c)
-        (error 'string-ref "BUG: got a non-char"))
+        (die 'string-ref "BUG: got a non-char"))
       c))
   
 
   (define string-set! 
     (lambda (s i c) 
       (unless (string? s) 
-        (error 'string-set! "not a string" s))
+        (die 'string-set! "not a string" s))
       (unless (fixnum? i)
-        (error 'string-set! "not a valid index" i))
+        (die 'string-set! "not a valid index" i))
       (unless (and ($fx< i ($string-length s))
                    ($fx>= i 0))
-        (error 'string-set! "index is out of range" i s))
+        (die 'string-set! "index is out of range" i s))
       (unless (char? c)
-        (error 'string-set! "not a character" c))
+        (die 'string-set! "not a character" c))
       ($string-set! s i c)))
   
   (define make-string
@@ -80,13 +80,13 @@
         (case-lambda
           [(n) 
            (unless (and (fixnum? n) (fx>= n 0))
-             (error 'make-string "not a valid length" n))
+             (die 'make-string "not a valid length" n))
            (fill! ($make-string n) 0 n (integer->char 0))]
           [(n c)
            (unless (and (fixnum? n) (fx>= n 0))
-             (error 'make-string "not a valid length" n))
+             (die 'make-string "not a valid length" n))
            (unless (char? c)
-             (error 'make-string "not a character" c))
+             (die 'make-string "not a character" c))
            (fill! ($make-string n) 0 n c)]))
         make-string))
 
@@ -98,7 +98,7 @@
                 (cond
                  [(null? ls) n]
                  [(char? ($car ls)) (length ($cdr ls) ($fx+ n 1))]
-                 [else (error 'string "not a character" ($car ls))]))]
+                 [else (die 'string "not a character" ($car ls))]))]
              [loop 
               (lambda (s ls i n)
                 (cond
@@ -122,18 +122,18 @@
     (define substring
        (lambda (s n m)
          (unless (string? s)
-           (error 'substring "not a string" s))
+           (die 'substring "not a string" s))
          (let ([len ($string-length s)])
            (unless (and (fixnum? n)
                         ($fx>= n 0)
                         ($fx<= n len))
-             (error 'substring "not a valid start index" n s))
+             (die 'substring "not a valid start index" n s))
            (unless (and (fixnum? m)
                         ($fx>= m 0)
                         ($fx<= m len))
-             (error 'substring "not a valid end index" m s))
+             (die 'substring "not a valid end index" m s))
            (unless ($fx<= n m)
-             (error 'substring "indices are in decreasing order" n m))
+             (die 'substring "indices are in decreasing order" n m))
            (let ([len ($fx- m n)])
              (if ($fx> len 0)
                  (fill s ($make-string len) n m 0)
@@ -143,7 +143,7 @@
     (lambda (s)
       (if (string? s)
           (substring s 0 (string-length s))
-          (error 'string-copy "not a string" s))))
+          (die 'string-copy "not a string" s))))
   
   (module (string=?)
     (define bstring=?
@@ -163,13 +163,13 @@
         (or (null? s*)
             (let ([a ($car s*)])
               (unless (string? a)
-                (error 'string=? "not a string" a))
+                (die 'string=? "not a string" a))
               (if ($fx= n ($string-length a))
                   (and (strings=? s ($cdr s*) n)
                        (bstring=? s a 0 n))
                   (check-strings-and-return-false ($cdr s*)))))))
     (define (err x)
-      (error 'string=? "not a string" x))
+      (die 'string=? "not a string" x))
     (define string=?
       (case-lambda
         [(s s1) 
@@ -203,10 +203,10 @@
                              [(string? (car s*)) 
                               (f (cdr s*))]
                              [else 
-                              (error who "not a string" 
+                              (die who "not a string" 
                                 (car s*))]))))
-                     (error who "not a string" s2))])))
-          (error who "not a string" s1)))
+                     (die who "not a string" s2))])))
+          (die who "not a string" s1)))
   
   (define ($string<? s1 s2)
     (let ([n1 ($string-length s1)]
@@ -270,8 +270,8 @@
        (if (string? s1)
            (if (string? s2) 
                ($string<? s1 s2)
-               (error 'string<? "not a string" s2))
-           (error 'string<? "not a string" s2))]
+               (die 'string<? "not a string" s2))
+           (die 'string<? "not a string" s2))]
       [(s . s*) 
        (string-cmp 'string<? $string<? s s*)]))
 
@@ -281,8 +281,8 @@
        (if (string? s1)
            (if (string? s2) 
                ($string<=? s1 s2)
-               (error 'string<=? "not a string" s2))
-           (error 'string<=? "not a string" s2))]
+               (die 'string<=? "not a string" s2))
+           (die 'string<=? "not a string" s2))]
       [(s . s*) 
        (string-cmp 'string<=? $string<=? s s*)]))
 
@@ -292,8 +292,8 @@
        (if (string? s1)
            (if (string? s2) 
                ($string>? s1 s2)
-               (error 'string>? "not a string" s2))
-           (error 'string>? "not a string" s2))]
+               (die 'string>? "not a string" s2))
+           (die 'string>? "not a string" s2))]
       [(s . s*) 
        (string-cmp 'string>? $string>? s s*)]))
 
@@ -303,15 +303,15 @@
        (if (string? s1)
            (if (string? s2) 
                ($string>=? s1 s2)
-               (error 'string>=? "not a string" s2))
-           (error 'string>=? "not a string" s2))]
+               (die 'string>=? "not a string" s2))
+           (die 'string>=? "not a string" s2))]
       [(s . s*) 
        (string-cmp 'string>=? $string>=? s s*)]))
 
   (define string->list
     (lambda (x)
       (unless (string? x)
-        (error 'string->list "not a string" x))
+        (die 'string->list "not a string" x))
       (let f ([x x] [i ($string-length x)] [ac '()])
         (cond
           [($fxzero? i) ac]
@@ -328,13 +328,13 @@
                       (if (pair? h)
                           (if (not (eq? h t))
                               (race ($cdr h) ($cdr t) ls ($fx+ n 2))
-                              (error 'reverse "circular list" ls))
+                              (die 'reverse "circular list" ls))
                           (if (null? h)
                               ($fx+ n 1)
-                              (error 'reverse "not a proper list" ls))))
+                              (die 'reverse "not a proper list" ls))))
                    (if (null? h)
                        n
-                       (error 'reverse "not a proper list" ls))))]
+                       (die 'reverse "not a proper list" ls))))]
               [fill
                (lambda (s i ls)
                  (cond
@@ -342,7 +342,7 @@
                    [else
                     (let ([c ($car ls)])
                       (unless (char? c)
-                        (error 'list->string "not a character" c))
+                        (die 'list->string "not a character" c))
                       ($string-set! s i c)
                       (fill s ($fxadd1 i) (cdr ls)))]))])
        (lambda (ls)
@@ -359,7 +359,7 @@
           [else
            (let ([a ($car s*)])
              (unless (string? a) 
-               (error 'string-append "not a string" a))
+               (die 'string-append "not a string" a))
              (length* ($cdr s*) ($fx+ n ($string-length a))))])))
     (define fill-string
       (lambda (s a si sj ai)
@@ -389,9 +389,9 @@
       (case-lambda
         [(p v) 
          (unless (procedure? p) 
-           (error who "not a procedure" p))
+           (die who "not a procedure" p))
          (unless (string? v) 
-           (error who "not a string" v))
+           (die who "not a string" v))
          (let f ([p p] [v v] [i 0] [n (string-length v)])
            (cond
              [($fx= i n) (void)]
@@ -400,14 +400,14 @@
               (f p v ($fxadd1 i) n)]))]
         [(p v0 v1) 
          (unless (procedure? p) 
-           (error who "not a procedure" p))
+           (die who "not a procedure" p))
          (unless (string? v0) 
-           (error who "not a string" v0))
+           (die who "not a string" v0))
          (unless (string? v1) 
-           (error who "not a string" v1))
+           (die who "not a string" v1))
          (let ([n (string-length v0)])
            (unless ($fx= n ($string-length v1))
-             (error who "length mismatch" v0 v1))
+             (die who "length mismatch" v0 v1))
            (let f ([p p] [v0 v0] [v1 v1] [i 0] [n n])
              (cond
                [($fx= i n) (void)]
@@ -416,21 +416,21 @@
                 (f p v0 v1 ($fxadd1 i) n)])))]
         [(p v0 v1 . v*) 
          (unless (procedure? p) 
-           (error who "not a procedure" p))
+           (die who "not a procedure" p))
          (unless (string? v0) 
-           (error who "not a string" v0))
+           (die who "not a string" v0))
          (unless (string? v1) 
-           (error who "not a string" v1))
+           (die who "not a string" v1))
          (let ([n (string-length v0)])
            (unless ($fx= n ($string-length v1))
-             (error who "length mismatch" v0 v1))
+             (die who "length mismatch" v0 v1))
            (let f ([v* v*] [n n])
              (unless (null? v*) 
                (let ([a ($car v*)])
                  (unless (string? a) 
-                   (error who "not a string" a))
+                   (die who "not a string" a))
                  (unless ($fx= ($string-length a) n) 
-                   (error who "length mismatch")))
+                   (die who "length mismatch")))
                (f ($cdr v*) n)))
            (let f ([p p] [v0 v0] [v1 v1] [v* v*] [i 0] [n n])
              (cond
@@ -446,9 +446,9 @@
 
   (define (string-fill! v fill)
     (unless (string? v) 
-      (error 'string-fill! "not a vector" v))
+      (die 'string-fill! "not a vector" v))
     (unless (char? fill)
-      (error 'string-fill! "not a character" fill))
+      (die 'string-fill! "not a character" fill))
     (let f ([v v] [i 0] [n ($string-length v)] [fill fill])
       (unless ($fx= i n) 
         ($string-set! v i fill)
@@ -459,21 +459,21 @@
     (lambda (src src-start dst dst-start k) 
       (cond
         [(or (not (fixnum? src-start)) ($fx< src-start 0))
-         (error 'string-copy! "not a valid starting index" src-start)]
+         (die 'string-copy! "not a valid starting index" src-start)]
         [(or (not (fixnum? dst-start)) ($fx< dst-start 0))
-         (error 'string-copy! "not a valid starting index" dst-start)]
+         (die 'string-copy! "not a valid starting index" dst-start)]
         [(or (not (fixnum? k)) ($fx< k 0))
-         (error 'string-copy! "not a valid length" k)]
+         (die 'string-copy! "not a valid length" k)]
         [(not (string? src)) 
-         (error 'string-copy! "not a string" src)]
+         (die 'string-copy! "not a string" src)]
         [(not (string? dst)) 
-         (error 'string-copy! "not a string" dst)]
+         (die 'string-copy! "not a string" dst)]
         [(let ([n ($fx+ src-start k)])
            (or ($fx< n 0) ($fx> n ($string-length src))))
-         (error 'string-copy! "out of range" src-start k)]
+         (die 'string-copy! "out of range" src-start k)]
         [(let ([n ($fx+ dst-start k)])
            (or ($fx< n 0) ($fx> n ($string-length dst))))
-         (error 'string-copy! "out of range" dst-start k)]
+         (die 'string-copy! "out of range" dst-start k)]
         [(eq? src dst)
          (cond
            [($fx< dst-start src-start)
@@ -499,5 +499,5 @@
       (let ([s ($make-bytevector 16)])
         (utf8->string
           (or (foreign-call "ik_uuid" s)
-              (error 'uuid "failed!"))))))
+              (die 'uuid "failed!"))))))
   )
diff --git a/scheme/ikarus.structs.ss b/scheme/ikarus.structs.ss
index 50ab1b7..44d620d 100644
--- a/scheme/ikarus.structs.ss
+++ b/scheme/ikarus.structs.ss
@@ -89,7 +89,7 @@
   (define verify-field
     (lambda (x)
       (unless (symbol? x) 
-        (error 'make-struct-type "not a valid field name" x))))
+        (die 'make-struct-type "not a valid field name" x))))
   
   (define set-fields
     (lambda (r f* i n)
@@ -110,9 +110,9 @@
     (case-lambda
       [(name fields)
        (unless (string? name)
-         (error 'make-struct-type "name must be a string" name))
+         (die 'make-struct-type "name must be a string" name))
        (unless (list? fields)
-         (error 'make-struct-type "fields must be a list" fields))
+         (die 'make-struct-type "fields must be a list" fields))
        (for-each verify-field fields)
        (let ([g (gensym name)])
          (let ([rtd (make-rtd name fields #f g)])
@@ -120,16 +120,16 @@
            rtd))]
       [(name fields g)
        (unless (string? name)
-         (error 'make-struct-type "name must be a string" name))
+         (die 'make-struct-type "name must be a string" name))
        (unless (list? fields)
-         (error 'make-struct-type "fields must be a list" fields))
+         (die 'make-struct-type "fields must be a list" fields))
        (for-each verify-field fields)
        (cond
          [(symbol-bound? g)
           (let ([rtd (symbol-value g)])
             (unless (and (string=? name (struct-type-name rtd))
                          (equal? fields (struct-type-field-names rtd)))
-              (error 'make-struct-type "definition mismatch"))
+              (die 'make-struct-type "definition mismatch"))
             rtd)]
          [else
           (let ([rtd (make-rtd name fields #f g)])
@@ -139,38 +139,38 @@
   (define struct-type-name
     (lambda (rtd)
       (unless (rtd? rtd)
-        (error 'struct-type-name "not an rtd" rtd))
+        (die 'struct-type-name "not an rtd" rtd))
       (rtd-name rtd)))
 
   (define struct-type-symbol
     (lambda (rtd)
       (unless (rtd? rtd)
-        (error 'struct-type-symbol "not an rtd" rtd))
+        (die 'struct-type-symbol "not an rtd" rtd))
       (rtd-symbol rtd)))
   
   (define struct-type-field-names
     (lambda (rtd)
       (unless (rtd? rtd)
-        (error 'struct-type-field-names "not an rtd" rtd))
+        (die 'struct-type-field-names "not an rtd" rtd))
       (rtd-fields rtd)))
  
 
   (define struct-constructor
     (lambda (rtd)
       (unless (rtd? rtd)
-        (error 'struct-constructor "not an rtd"))
+        (die 'struct-constructor "not an rtd"))
       (lambda args
         (let ([n (rtd-length rtd)])
           (let ([r ($make-struct rtd n)])
             (or (set-fields r args 0 n)
-                (error 'struct-constructor 
+                (die 'struct-constructor 
                   "incorrect number of arguments to the constructor" 
                   rtd)))))))
   
   (define struct-predicate
     (lambda (rtd)
       (unless (rtd? rtd)
-        (error 'struct-predicate "not an rtd"))
+        (die 'struct-predicate "not an rtd"))
       (lambda (x)
         (and ($struct? x)
              (eq? ($struct-rtd x) rtd)))))
@@ -180,39 +180,39 @@
       (cond
         [(fixnum? i)
          (unless (and ($fx>= i 0) ($fx< i (rtd-length rtd)))
-           (error who "out of range for rtd" i rtd))
+           (die who "out of range for rtd" i rtd))
          i]
         [(symbol? i)
          (letrec ([lookup
                    (lambda (n ls)
                      (cond
                        [(null? ls) 
-                        (error who "not a field" rtd)]
+                        (die who "not a field" rtd)]
                        [(eq? i ($car ls)) n]
                        [else (lookup ($fx+ n 1) ($cdr ls))]))])
            (lookup 0 (rtd-fields rtd)))]
-        [else (error who "not a valid index" i)])))
+        [else (die who "not a valid index" i)])))
 
   (define struct-field-accessor
     (lambda (rtd i)
       (unless (rtd? rtd)
-        (error 'struct-field-accessor "not an rtd" rtd))
+        (die 'struct-field-accessor "not an rtd" rtd))
       (let ([i (field-index i rtd 'struct-field-accessor)])
         (lambda (x)
           (unless (and ($struct? x) 
                        (eq? ($struct-rtd x) rtd))
-            (error 'struct-field-accessor "not of correct type" x rtd))
+            (die 'struct-field-accessor "not of correct type" x rtd))
           ($struct-ref x i)))))
 
   (define struct-field-mutator
     (lambda (rtd i)
       (unless (rtd? rtd)
-        (error 'struct-field-mutator "not an rtd" rtd))
+        (die 'struct-field-mutator "not an rtd" rtd))
       (let ([i (field-index i rtd 'struct-field-mutator)])
         (lambda (x v)
           (unless (and ($struct? x) 
                        (eq? ($struct-rtd x) rtd))
-            (error 'struct-field-mutator "not of correct type" x rtd))
+            (die 'struct-field-mutator "not of correct type" x rtd))
           ($struct-set! x i v)))))
 
   (define struct?
@@ -221,9 +221,9 @@
           ($struct? x)
           (let ([rtd ($car rest)])
             (unless (null? ($cdr rest))
-              (error 'struct? "too many arguments"))
+              (die 'struct? "too many arguments"))
             (unless (rtd? rtd)
-              (error 'struct? "not an rtd"))
+              (die 'struct? "not an rtd"))
             (and ($struct? x)
                  (eq? ($struct-rtd x) rtd))))))
 
@@ -231,49 +231,49 @@
     (lambda (x)
       (if ($struct? x)
           ($struct-rtd x)
-          (error 'struct-rtd "not a struct" x))))
+          (die 'struct-rtd "not a struct" x))))
 
   (define struct-length
     (lambda (x)
       (if ($struct? x)
           (rtd-length ($struct-rtd x))
-          (error 'struct-length "not a struct" x))))
+          (die 'struct-length "not a struct" x))))
             
   (define struct-name
     (lambda (x)
       (if ($struct? x)
           (rtd-name ($struct-rtd x))
-          (error 'struct-name "not a struct" x))))
+          (die 'struct-name "not a struct" x))))
 
   (define struct-printer
     (lambda (x)
       (if ($struct? x)
           (rtd-printer ($struct-rtd x))
-          (error 'struct-printer "not a struct" x))))
+          (die 'struct-printer "not a struct" x))))
 
   (define struct-ref
     (lambda (x i)
-      (unless ($struct? x) (error 'struct-ref "not a struct" x))
-      (unless (fixnum? i) (error 'struct-ref "not a valid index" i))
+      (unless ($struct? x) (die 'struct-ref "not a struct" x))
+      (unless (fixnum? i) (die 'struct-ref "not a valid index" i))
       (let ([n (rtd-length ($struct-rtd x))])
         (unless (and ($fx>= i 0) ($fx< i n))
-          (error 'struct-ref "index is out of range" i x))
+          (die 'struct-ref "index is out of range" i x))
         ($struct-ref x i))))
 
   (define struct-set!
     (lambda (x i v)
-      (unless ($struct? x) (error 'struct-set! "not a struct" x))
-      (unless (fixnum? i) (error 'struct-set! "not a valid index" i))
+      (unless ($struct? x) (die 'struct-set! "not a struct" x))
+      (unless (fixnum? i) (die 'struct-set! "not a valid index" i))
       (let ([n (rtd-length ($struct-rtd x))])
         (unless (and ($fx>= i 0) ($fx< i n))
-          (error 'struct-set! "index is out of range" i x))
+          (die 'struct-set! "index is out of range" i x))
         ($struct-set! x i v))))
 
   (define (set-rtd-printer! x p)
     (unless (rtd? x)
-      (error 'set-rtd-printer! "not an rtd" x))
+      (die 'set-rtd-printer! "not an rtd" x))
     (unless (procedure? p)
-      (error 'set-rtd-printer! "not a procedure" p))
+      (die 'set-rtd-printer! "not a procedure" p))
     ($set-rtd-printer! x p))
 
   (set-rtd-fields! (base-rtd) '(name fields length printer symbol))
@@ -281,7 +281,7 @@
   ($set-rtd-printer! (base-rtd)
     (lambda (x p)
       (unless (rtd? x)
-        (error 'struct-type-printer "not an rtd"))
+        (die 'struct-type-printer "not an rtd"))
       (display "#<" p)
       (display (rtd-name x) p)
       (display " rtd>" p)))
diff --git a/scheme/ikarus.symbols.ss b/scheme/ikarus.symbols.ss
index 1726ac6..82d3cd0 100644
--- a/scheme/ikarus.symbols.ss
+++ b/scheme/ikarus.symbols.ss
@@ -40,7 +40,7 @@
            ($make-symbol s)
            (if (symbol? s)
                ($make-symbol ($symbol-string s))
-               (error 'gensym "neither a string nor a symbol" s)))]))
+               (die 'gensym "neither a string nor a symbol" s)))]))
 
   (define gensym?
     (lambda (x)
@@ -51,10 +51,10 @@
   (define top-level-value
     (lambda (x)
       (unless (symbol? x)
-        (error 'top-level-value "not a symbol" x))
+        (die 'top-level-value "not a symbol" x))
       (let ([v ($symbol-value x)])
         (when ($unbound-object? v)
-          (error 'eval "unbound variable" 
+          (die 'eval "unbound variable" 
             (string->symbol
               (symbol->string x))))
         v)))
@@ -62,39 +62,39 @@
   (define top-level-bound?
     (lambda (x)
       (unless (symbol? x)
-        (error 'top-level-bound? "not a symbol" x))
+        (die 'top-level-bound? "not a symbol" x))
       (not ($unbound-object? ($symbol-value x)))))
 
   (define set-top-level-value!
     (lambda (x v)
       (unless (symbol? x)
-        (error 'set-top-level-value! "not a symbol" x))
+        (die 'set-top-level-value! "not a symbol" x))
       ($set-symbol-value! x v)))
 
   (define symbol-value
     (lambda (x)
       (unless (symbol? x)
-        (error 'symbol-value "not a symbol" x))
+        (die 'symbol-value "not a symbol" x))
       (let ([v ($symbol-value x)])
         (when ($unbound-object? v)
-          (error 'symbol-value "unbound" x))
+          (die 'symbol-value "unbound" x))
         v)))
 
   (define symbol-bound?
     (lambda (x)
       (unless (symbol? x)
-        (error 'symbol-bound? "not a symbol" x))
+        (die 'symbol-bound? "not a symbol" x))
       (not ($unbound-object? ($symbol-value x)))))
 
   (define set-symbol-value!
     (lambda (x v)
       (unless (symbol? x)
-        (error 'set-symbol-value! "not a symbol" x))
+        (die 'set-symbol-value! "not a symbol" x))
       ($set-symbol-value! x v)
       ($set-symbol-proc! x 
         (if (procedure? v) v 
             (lambda args
-              (error 'apply "not a procedure" 
+              (die 'apply "not a procedure" 
                      ($symbol-value x)))))))
          
   (define reset-symbol-proc!
@@ -106,21 +106,21 @@
               (lambda args
                 (let ([v ($symbol-value x)])
                   (if ($unbound-object? v)
-                      (error 'eval "unbound variable" 
+                      (die 'eval "unbound variable" 
                         (string->symbol
                           (symbol->string x)))
-                      (error 'apply "not a procedure" v)))))))))
+                      (die 'apply "not a procedure" v)))))))))
 
   (define string->symbol
     (lambda (x)
       (unless (string? x) 
-        (error 'string->symbol "not a string" x))
+        (die 'string->symbol "not a string" x))
       (foreign-call "ikrt_string_to_symbol" x)))
   
   (define symbol->string
     (lambda (x)
       (unless (symbol? x)
-        (error 'symbol->string "not a symbol" x))
+        (die 'symbol->string "not a symbol" x))
       (let ([str ($symbol-string x)])
         (or str
             (let ([ct (gensym-count)])
@@ -132,8 +132,8 @@
 
   (define putprop
     (lambda (x k v)
-      (unless (symbol? x) (error 'putprop "not a symbol" x))
-      (unless (symbol? k) (error 'putprop "not a symbol" k))
+      (unless (symbol? x) (die 'putprop "not a symbol" x))
+      (unless (symbol? k) (die 'putprop "not a symbol" k))
       (let ([p ($symbol-plist x)])
         (cond
           [(assq k p) => (lambda (x) (set-cdr! x v))]
@@ -142,8 +142,8 @@
 
   (define getprop
     (lambda (x k)
-      (unless (symbol? x) (error 'getprop "not a symbol" x))
-      (unless (symbol? k) (error 'getprop "not a symbol" k))
+      (unless (symbol? x) (die 'getprop "not a symbol" x))
+      (unless (symbol? k) (die 'getprop "not a symbol" k))
       (let ([p ($symbol-plist x)])
         (cond
           [(assq k p) => cdr]
@@ -151,8 +151,8 @@
 
   (define remprop
     (lambda (x k)
-      (unless (symbol? x) (error 'remprop "not a symbol" x))
-      (unless (symbol? k) (error 'remprop "not a symbol" k))
+      (unless (symbol? x) (die 'remprop "not a symbol" x))
+      (unless (symbol? k) (die 'remprop "not a symbol" k))
       (let ([p ($symbol-plist x)])
         (unless (null? p)
           (let ([a ($car p)])
@@ -171,7 +171,7 @@
   (define property-list
     (lambda (x)
       (unless (symbol? x)
-        (error 'property-list "not a symbol" x))
+        (die 'property-list "not a symbol" x))
       (letrec ([f 
                 (lambda (ls ac)
                   (cond
@@ -185,12 +185,12 @@
   (define gensym->unique-string
     (lambda (x)
       (unless (symbol? x)
-        (error 'gensym->unique-string "not a gensym" x))
+        (die 'gensym->unique-string "not a gensym" x))
       (let ([us ($symbol-unique-string x)])
         (cond
           [(string? us) us]
           [(not us)
-           (error 'gensym->unique-string "not a gensym" x)]
+           (die 'gensym->unique-string "not a gensym" x)]
           [else
            (let f ([x x])
              (let ([id (uuid)])
@@ -204,7 +204,7 @@
       "g"
       (lambda (x)
         (unless (string? x)
-          (error 'gensym-prefix "not a string" x))
+          (die 'gensym-prefix "not a string" x))
         x)))
   
   (define gensym-count
@@ -212,7 +212,7 @@
       0
       (lambda (x)
         (unless (and (fixnum? x) ($fx>= x 0))
-          (error 'gensym-count "not a valid count" x))
+          (die 'gensym-count "not a valid count" x))
         x)))
   
   (define print-gensym
@@ -220,7 +220,7 @@
       #t
       (lambda (x)
         (unless (or (boolean? x) (eq? x 'pretty))
-          (error 'print-gensym "not in #t|#f|pretty" x))
+          (die 'print-gensym "not in #t|#f|pretty" x))
         x)))
 
   )
diff --git a/scheme/ikarus.time-and-date.ss b/scheme/ikarus.time-and-date.ss
index ed822a5..12be1c8 100644
--- a/scheme/ikarus.time-and-date.ss
+++ b/scheme/ikarus.time-and-date.ss
@@ -31,16 +31,16 @@
     (if (time? x) 
         (+ (* (time-msecs x) #e10e5)
            (time-secs x))
-        (error 'time-second "not a time" x)))
+        (die 'time-second "not a time" x)))
   
   (define (time-nanosecond x)
     (if (time? x) 
         (* (time-usecs x) 1000)
-        (error 'time-nanosecond "not a time" x)))
+        (die 'time-nanosecond "not a time" x)))
 
   (define (time-gmt-offset x)
     (if (time? x) 
         (foreign-call "ikrt_gmt_offset" x)
-        (error 'time-gmt-offset "not a time" x)))
+        (die 'time-gmt-offset "not a time" x)))
   )
 
diff --git a/scheme/ikarus.timer.ss b/scheme/ikarus.timer.ss
index 65464f8..788030c 100644
--- a/scheme/ikarus.timer.ss
+++ b/scheme/ikarus.timer.ss
@@ -86,7 +86,7 @@
        (time-it #f proc)]
       [(message proc)
        (unless (procedure? proc)
-         (error 'time-it "not a procedure" proc))
+         (die 'time-it "not a procedure" proc))
        (let* ([t0 (mk-stats)]
               [t1 (mk-stats)]
               [bytes-min (bytes-minor)]
diff --git a/scheme/ikarus.trace.ss b/scheme/ikarus.trace.ss
index d7f19f0..8bdebbc 100644
--- a/scheme/ikarus.trace.ss
+++ b/scheme/ikarus.trace.ss
@@ -98,7 +98,7 @@
            (let ([a (cdr pr)] [v (symbol-value s)])
              (unless (eq? (cdr a) v)
                (unless (procedure? v)
-                 (error 'trace
+                 (die 'trace
                         "the top-level value is not a procedure"
                      s v))
                (let ([p (make-traced-procedure s v)])
@@ -107,10 +107,10 @@
                  (set-symbol-value! s p)))))]
         [else
          (unless (symbol-bound? s)
-           (error 'trace "unbound" s))
+           (die 'trace "unbound" s))
          (let ([v (symbol-value s)])
            (unless (procedure? v)
-             (error 'trace "the top-level value is not a procedure" s v))
+             (die 'trace "the top-level value is not a procedure" s v))
            (let ([p (make-traced-procedure s v)])
              (set! traced-symbols 
                (cons (cons s (cons v p)) traced-symbols))
diff --git a/scheme/ikarus.unicode-conversion.ss b/scheme/ikarus.unicode-conversion.ss
index b0b5a6e..c065b0d 100644
--- a/scheme/ikarus.unicode-conversion.ss
+++ b/scheme/ikarus.unicode-conversion.ss
@@ -37,7 +37,7 @@
   ;;; handling-modes: ignore, replace, raise
   ;;; ignore: skips over the offending bytes
   ;;; replace: places a U+FFFD in place of the malformed bytes
-  ;;; raise: raises an error
+  ;;; raise: raises an die
 
   ;;; It appears that utf-8 data can start with a #xEF #xBB #xBF BOM!
 
@@ -102,14 +102,14 @@
                      ($fxlogor #b10000000 ($fxlogand b #b111111)))
                    (f bv str ($fxadd1 i) ($fx+ j 4) n)])))])))
       (unless (string? str) 
-        (error 'string->utf8 "not a string" str))
+        (die 'string->utf8 "not a string" str))
       (fill-utf8-bytevector
         ($make-bytevector (utf8-string-size str))
         str)))
 
   (define (utf8->string x) 
     (unless (bytevector? x) 
-      (error 'utf8->string "not a bytevector" x))
+      (die 'utf8->string "not a bytevector" x))
     (decode-utf8-bytevector x 'replace))
 
   (define decode-utf8-bytevector
@@ -142,12 +142,12 @@
                            [(eq? mode 'replace) 
                             (f x i j ($fxadd1 n) mode)]
                            [else
-                            (error who "invalid byte sequence at idx of bytevector"
+                            (die who "invalid byte sequence at idx of bytevector"
                                    b0 b1 i bv)]))]
                       [(eq? mode 'ignore) n]
                       [(eq? mode 'replace) ($fxadd1 n)]
                       [else
-                       (error who "invalid byte near end of bytevector" b0)]))]
+                       (die who "invalid byte near end of bytevector" b0)]))]
                  [($fx= ($fxsra b0 4) #b1110)
                   (cond
                     [($fx< ($fx+ i 2) j) 
@@ -165,10 +165,10 @@
                           (f x ($fxadd1 i) j n mode)]
                          [(eq? mode 'replace)
                           (f x ($fxadd1 i) j ($fxadd1 n) mode)]
-                         [else (error who "invalid sequence" b0 b1 b2)]))]
+                         [else (die who "invalid sequence" b0 b1 b2)]))]
                     [(eq? mode 'ignore) (f x ($fxadd1 i) j n mode)]
                     [(eq? mode 'replace) (f x ($fxadd1 i) j ($fxadd1 n) mode)]
-                    [else (error who "incomplete char sequence")])]
+                    [else (die who "incomplete char sequence")])]
                  [($fx= ($fxsra b0 3) #b11110)
                   (cond
                     [($fx< ($fx+ i 3) j) 
@@ -189,13 +189,13 @@
                           (f x ($fxadd1 i) j n mode)]
                          [(eq? mode 'replace)
                           (f x ($fxadd1 i) j ($fxadd1 n) mode)]
-                         [else (error who "invalid sequence" b0 b1 b2 b3)]))]
+                         [else (die who "invalid sequence" b0 b1 b2 b3)]))]
                     [(eq? mode 'ignore) (f x ($fxadd1 i) j n mode)]
                     [(eq? mode 'replace) (f x ($fxadd1 i) j ($fxadd1 n) mode)]
-                    [else (error who "incomplete char sequence")])]
+                    [else (die who "incomplete char sequence")])]
                  [(eq? mode 'ignore) (f x ($fxadd1 i) j n mode)]
                  [(eq? mode 'replace) (f x ($fxadd1 i) j ($fxadd1 n) mode)]
-                 [else (error who "invalid byte at index of bytevector" b0 i x)]))])))
+                 [else (die who "invalid byte at index of bytevector" b0 i x)]))])))
       (define (fill str bv i mode)
         (let f ([str str] [x bv] [i i] [j ($bytevector-length bv)] [n 0] [mode mode])
           (cond
@@ -227,12 +227,12 @@
                            [(eq? mode 'replace)
                             ($string-set! str n ($fixnum->char #xFFFD))
                             (f str x i j ($fxadd1 n) mode)]
-                           [else (error who "BUG")]))]
+                           [else (die who "BUG")]))]
                       [(eq? mode 'ignore) str]
                       [(eq? mode 'replace) 
                        ($string-set! str n ($fixnum->char #xFFFD))
                        str]
-                      [else (error who "BUG")]))]
+                      [else (die who "BUG")]))]
                  [($fx= ($fxsra b0 4) #b1110)
                   (cond
                     [($fx< ($fx+ i 2) j) 
@@ -254,12 +254,12 @@
                          [(eq? mode 'replace)
                           ($string-set! str n ($fixnum->char #xFFFD))
                           (f str x ($fxadd1 i) j ($fxadd1 n) mode)]
-                         [else (error who "BUG")]))]
+                         [else (die who "BUG")]))]
                     [(eq? mode 'ignore) (f str x ($fxadd1 i) j n mode)]
                     [(eq? mode 'replace) 
                      ($string-set! str n ($fixnum->char #xFFFD))
                      (f str x ($fxadd1 i) j ($fxadd1 n) mode)]
-                    [else (error who "BUG")])]
+                    [else (die who "BUG")])]
                  [($fx= ($fxsra b0 3) #b11110)
                   (cond
                     [($fx< ($fx+ i 3) j) 
@@ -285,17 +285,17 @@
                          [(eq? mode 'replace)
                           ($string-set! str n ($fixnum->char #xFFFD))
                           (f str x ($fxadd1 i) j ($fxadd1 n) mode)]
-                         [else (error who "BUG")]))]
+                         [else (die who "BUG")]))]
                     [(eq? mode 'ignore) (f str x ($fxadd1 i) j n mode)]
                     [(eq? mode 'replace) 
                      ($string-set! str n ($fixnum->char #xFFFD))
                      (f str x ($fxadd1 i) j ($fxadd1 n) mode)]
-                    [else (error who "BUG")])]
+                    [else (die who "BUG")])]
                  [(eq? mode 'ignore) (f str x ($fxadd1 i) j n mode)]
                  [(eq? mode 'replace)
                   ($string-set! str n ($fixnum->char #xFFFD))
                   (f str x ($fxadd1 i) j ($fxadd1 n) mode)]
-                 [else (error who "BUG")]))])))
+                 [else (die who "BUG")]))])))
       (define (has-bom? bv) 
         (and (fx> (bytevector-length bv) 3) 
              (fx= (bytevector-u8-ref bv 0) #xEF)
@@ -311,7 +311,7 @@
         [(bv) (convert bv 'raise)]
         [(bv handling-mode)
          (unless (memq handling-mode '(ignore replace raise)) 
-           (error 'decode-utf8-bytevector
+           (die 'decode-utf8-bytevector
                   "not a valid handling mode"
                   handling-mode))
          (convert bv handling-mode)])))
@@ -353,7 +353,7 @@
 ;;;      of W1. Terminate.
 ;;;
 ;;;   2) Determine if W1 is between 0xD800 and 0xDBFF. If not, the sequence
-;;;      is in error and no valid character can be obtained using W1.
+;;;      is in die and no valid character can be obtained using W1.
 ;;;      Terminate.
 ;;;
 ;;;   3) If there is no W2 (that is, the sequence ends with W1), or if W2
@@ -407,13 +407,13 @@
       (case-lambda
         [(str) 
          (unless (string? str)
-           (error 'string->utf16 "not a string" str))
+           (die 'string->utf16 "not a string" str))
          ($string->utf16 str 'big)]
         [(str endianness)
          (unless (string? str)
-           (error 'string->utf16 "not a string" str))
+           (die 'string->utf16 "not a string" str))
          (unless (memv endianness '(big little))
-           (error 'string->utf16 "invalid endianness" endianness))
+           (die 'string->utf16 "invalid endianness" endianness))
          ($string->utf16 str endianness)])))
 
   (module (utf16->string)
@@ -429,20 +429,20 @@
            (cond
              [(or (fx< w1 #xD800) (fx> w1 #xDFFF))
               (count-size bv endianness (+ i 2) len (+ n 1))]
-             [(not (fx<= #xD800 w1 #xDBFF)) ;;; error sequence
+             [(not (fx<= #xD800 w1 #xDBFF)) ;;; die sequence
               (count-size bv endianness (+ i 2) len (+ n 1))]
              [(<= (+ i 4) (bytevector-length bv))
               (let ([w2 (bytevector-u16-ref bv (+ i 2) endianness)])
                 (cond
                   [(not (<= #xDC00 w2 #xDFFF)) 
                    ;;; do we skip w2 also?
-                   ;;; I won't.  Just w1 is an error
+                   ;;; I won't.  Just w1 is an die
                    (count-size bv endianness (+ i 2) len (+ n 1))]
                   [else 
                    ;;; 4-byte sequence is ok
                    (count-size bv endianness (+ i 4) len (+ n 1))]))]
              [else 
-              ;;; error again
+              ;;; die again
               (count-size bv endianness (+ i 2) len (+ n 1))]))]))
     (define (fill bv endianness str i len n)
       (cond
@@ -456,7 +456,7 @@
              [(or (fx< w1 #xD800) (fx> w1 #xDFFF))
               (string-set! str n (integer->char/invalid w1))
               (fill bv endianness str (+ i 2) len (+ n 1))]
-             [(not (fx<= #xD800 w1 #xDBFF)) ;;; error sequence
+             [(not (fx<= #xD800 w1 #xDBFF)) ;;; die sequence
               (string-set! str n #\xFFFD)
               (fill bv endianness str (+ i 2) len (+ n 1))]
              [(<= (+ i 4) (bytevector-length bv))
@@ -464,7 +464,7 @@
                 (cond
                   [(not (<= #xDC00 w2 #xDFFF)) 
                    ;;; do we skip w2 also?
-                   ;;; I won't.  Just w1 is an error
+                   ;;; I won't.  Just w1 is an die
                    (string-set! str n #\xFFFD)
                    (fill bv endianness str (+ i 2) len (+ n 1))]
                   [else 
@@ -475,7 +475,7 @@
                                   (fxlogand w2 #x3FF)))))
                    (fill bv endianness str (+ i 4) len (+ n 1))]))]
              [else 
-              ;;; error again
+              ;;; die again
               (string-set! str n #\xFFFD)
               (fill bv endianness str (+ i 2) len (+ n 1))]))]))
     (define (decode bv endianness start)
@@ -492,9 +492,9 @@
                  [(fx= n #xFFFE) 'little]
                  [else #f]))))
       (unless (bytevector? bv)
-        (error who "not a bytevector" bv))
+        (die who "not a bytevector" bv))
       (unless (memv endianness '(big little))
-        (error who "invalid endianness" endianness))
+        (die who "invalid endianness" endianness))
       (cond
         [em?  (decode bv endianness 0)]
         [(bom-present bv) =>
@@ -528,13 +528,13 @@
       (case-lambda
         [(str) 
          (unless (string? str)
-           (error who "not a string" str))
+           (die who "not a string" str))
          ($string->utf32 str 'big)]
         [(str endianness)
          (unless (string? str)
-           (error who "not a string" str))
+           (die who "not a string" str))
          (unless (memq endianness '(little big))
-           (error who "invalid endianness" endianness))
+           (die who "invalid endianness" endianness))
          ($string->utf32 str endianness)])))
 
 
@@ -567,9 +567,9 @@
                  [(= n #xFFFE0000) 'little]
                  [else #f]))))
       (unless (bytevector? bv)
-        (error who "not a bytevector" bv))
+        (die who "not a bytevector" bv))
       (unless (memv endianness '(big little))
-        (error who "invalid endianness" endianness))
+        (die who "invalid endianness" endianness))
       (cond
         [em? (decode bv endianness 0)]
         [(bom-present bv) =>
diff --git a/scheme/ikarus.unicode-data.ss b/scheme/ikarus.unicode-data.ss
index faa610d..edab8c0 100644
--- a/scheme/ikarus.unicode-data.ss
+++ b/scheme/ikarus.unicode-data.ss
@@ -77,12 +77,12 @@
     (if (char? c) 
         (vector-ref unicode-categories-name-vector
           (fxlogand 63 (lookup-char-info c)))
-        (error 'char-general-category "not a char" c)))
+        (die 'char-general-category "not a char" c)))
 
   (define (char-has-property? c prop-val who)
     (if (char? c) 
         (not (fxzero? (fxlogand (lookup-char-info c) prop-val)))
-        (error who "not a char" c)))
+        (die who "not a char" c)))
 
   (define (unicode-printable-char? c) 
     (char-has-property? c constituent-property 'unicode-printable-char?))
@@ -112,24 +112,24 @@
     (if (char? x) 
         ($fixnum->char
           (convert-char x char-downcase-adjustment-vector))
-        (error 'char-downcase "not a character" x)))
+        (die 'char-downcase "not a character" x)))
 
   (define (char-upcase x)
     (if (char? x) 
         ($fixnum->char
           (convert-char x char-upcase-adjustment-vector))
-        (error 'char-downcase "not a character" x)))
+        (die 'char-downcase "not a character" x)))
   
   (define (char-titlecase x)
     (if (char? x) 
         ($fixnum->char
           (convert-char x char-titlecase-adjustment-vector))
-        (error 'char-downcase "not a character" x)))
+        (die 'char-downcase "not a character" x)))
 
   (define (char-foldcase x)
     (if (char? x)
         ($fixnum->char ($fold x))
-        (error 'char-downcase "not a character" x)))
+        (die 'char-downcase "not a character" x)))
 
   (define ($fold x) 
     (convert-char x char-foldcase-adjustment-vector))
@@ -137,7 +137,7 @@
   (define (char-ci-loop c0 ls p? who) 
     (or (null? ls)
         (let ([c1 (car ls)])
-          (unless (char? c1) (error who "not a char" c1))
+          (unless (char? c1) (die who "not a char" c1))
           (let ([c1 ($fold c1)])
             (if (p? c0 c1) 
                 (char-ci-loop c1 (cdr ls) p? who)
@@ -146,7 +146,7 @@
                     [(null? ls) #f]
                     [(char? (car ls)) 
                      (f (cdr ls) who)]
-                    [else (error who "not a char" (car ls))])))))))
+                    [else (die who "not a char" (car ls))])))))))
 
   (define char-ci=? 
     (case-lambda 
@@ -155,14 +155,14 @@
            (or (eq? x y)
                (if (char? y)
                    ($fx= ($fold x) ($fold y))
-                   (error 'char-ci=? "not a char" y)))
-           (error 'char-ci=? "not a char" x))]
+                   (die 'char-ci=? "not a char" y)))
+           (die 'char-ci=? "not a char" x))]
       [(x)
-       (or (char? x) (error 'char-ci=? "not a char" x))]
+       (or (char? x) (die 'char-ci=? "not a char" x))]
       [(x . x*) 
        (if (char? x) 
            (char-ci-loop x x* char=? 'char-ci=?)
-           (error 'char-ci=? "not a char" x))]))
+           (die 'char-ci=? "not a char" x))]))
 
   (define char-ci<? 
     (case-lambda 
@@ -171,14 +171,14 @@
            (or (eq? x y)
                (if (char? y)
                    ($fx< ($fold x) ($fold y))
-                   (error 'char-ci<? "not a char" y)))
-           (error 'char-ci<? "not a char" x))]
+                   (die 'char-ci<? "not a char" y)))
+           (die 'char-ci<? "not a char" x))]
       [(x)
-       (or (char? x) (error 'char-ci<? "not a char" x))]
+       (or (char? x) (die 'char-ci<? "not a char" x))]
       [(x . x*) 
        (if (char? x) 
            (char-ci-loop x x* char<? 'char-ci<?)
-           (error 'char-ci<? "not a char" x))]))
+           (die 'char-ci<? "not a char" x))]))
 
   (define char-ci<=? 
     (case-lambda 
@@ -187,14 +187,14 @@
            (or (eq? x y)
                (if (char? y)
                    ($fx<= ($fold x) ($fold y))
-                   (error 'char-ci<=? "not a char" y)))
-           (error 'char-ci<=? "not a char" x))]
+                   (die 'char-ci<=? "not a char" y)))
+           (die 'char-ci<=? "not a char" x))]
       [(x)
-       (or (char? x) (error 'char-ci<=? "not a char" x))]
+       (or (char? x) (die 'char-ci<=? "not a char" x))]
       [(x . x*) 
        (if (char? x) 
            (char-ci-loop x x* char<=? 'char-ci<=?)
-           (error 'char-ci<=? "not a char" x))]))
+           (die 'char-ci<=? "not a char" x))]))
 
   (define char-ci>? 
     (case-lambda 
@@ -203,14 +203,14 @@
            (or (eq? x y)
                (if (char? y)
                    ($fx> ($fold x) ($fold y))
-                   (error 'char-ci>? "not a char" y)))
-           (error 'char-ci>? "not a char" x))]
+                   (die 'char-ci>? "not a char" y)))
+           (die 'char-ci>? "not a char" x))]
       [(x)
-       (or (char? x) (error 'char-ci>? "not a char" x))]
+       (or (char? x) (die 'char-ci>? "not a char" x))]
       [(x . x*) 
        (if (char? x) 
            (char-ci-loop x x* char>? 'char-ci>?)
-           (error 'char-ci>? "not a char" x))]))
+           (die 'char-ci>? "not a char" x))]))
   
   (define char-ci>=? 
     (case-lambda 
@@ -219,14 +219,14 @@
            (or (eq? x y)
                (if (char? y)
                    ($fx>= ($fold x) ($fold y))
-                   (error 'char-ci>=? "not a char" y)))
-           (error 'char-ci>=? "not a char" x))]
+                   (die 'char-ci>=? "not a char" y)))
+           (die 'char-ci>=? "not a char" x))]
       [(x)
-       (or (char? x) (error 'char-ci>=? "not a char" x))]
+       (or (char? x) (die 'char-ci>=? "not a char" x))]
       [(x . x*) 
        (if (char? x) 
            (char-ci-loop x x* char>=? 'char-ci>=?)
-           (error 'char-ci>=? "not a char" x))]))
+           (die 'char-ci>=? "not a char" x))]))
                
   (define ($string-foldcase str)
     (define (extend-length str ac) 
@@ -282,7 +282,7 @@
   (define (string-foldcase str)
     (if (string? str)
         ($string-foldcase str)
-        (error 'string-foldcase "not a string" str)))
+        (die 'string-foldcase "not a string" str)))
 
   ;;; FIXME: case-insensitive comparison procedures are slow.
 
@@ -293,8 +293,8 @@
          (if (string? s1)
              (if (string? s2) 
                  (cmp ($string-foldcase s1) ($string-foldcase s2))
-                 (error who "not a string" s2))
-             (error who "not a string" s1))]
+                 (die who "not a string" s2))
+             (die who "not a string" s1))]
         [(s1 . s*) 
          (if (string? s1) 
              (let ([s1 ($string-foldcase s1)])
@@ -313,10 +313,10 @@
                                     [(string? (car s*)) 
                                      (f (cdr s*))]
                                     [else 
-                                     (error who "not a string" 
+                                     (die who "not a string" 
                                        (car s*))]))))
-                          (error who "not a string" s2)))])))
-             (error who "not a string" s1))])))
+                          (die who "not a string" s2)))])))
+             (die who "not a string" s1))])))
 
 
   (define string-ci=?  (string-ci-cmp 'string-ci=? string=?))
diff --git a/scheme/ikarus.vectors.ss b/scheme/ikarus.vectors.ss
index 7a722f8..0224f15 100644
--- a/scheme/ikarus.vectors.ss
+++ b/scheme/ikarus.vectors.ss
@@ -31,7 +31,7 @@
   (define vector-length
     (lambda (x)
       (unless (vector? x) 
-        (error 'vector-length "not a vector" x))
+        (die 'vector-length "not a vector" x))
       ($vector-length x)))
 
   (module (make-vector)
@@ -47,7 +47,7 @@
         [(n) (make-vector n (void))]
         [(n fill)
          (unless (and (fixnum? n) ($fx>= n 0))
-           (error 'make-vector "not a valid length" n))
+           (die 'make-vector "not a valid length" n))
          (fill! ($make-vector n) 0 n fill)])))
 
 
@@ -74,23 +74,23 @@
   (define vector-ref 
     (lambda (v i)
       (unless (vector? v)
-        (error 'vector-ref "not a vector" v))
+        (die 'vector-ref "not a vector" v))
       (unless (fixnum? i)
-        (error 'vector-ref "not a valid index" i))
+        (die 'vector-ref "not a valid index" i))
       (unless (and ($fx< i ($vector-length v))
                    ($fx<= 0 i))
-        (error 'vector-ref "index is out of range" i v))
+        (die 'vector-ref "index is out of range" i v))
       ($vector-ref v i)))
   
   (define vector-set! 
     (lambda (v i c) 
       (unless (vector? v) 
-        (error 'vector-set! "not a vector" v))
+        (die 'vector-set! "not a vector" v))
       (unless (fixnum? i)
-        (error 'vector-set! "not a valid index" i))
+        (die 'vector-set! "not a valid index" i))
       (unless (and ($fx< i ($vector-length v))
                    ($fx<= 0 i))
-        (error 'vector-set! "index is out of range" i v))
+        (die 'vector-set! "index is out of range" i v))
       ($vector-set! v i c)))
 
   (define vector->list
@@ -106,7 +106,7 @@
             (if ($fxzero? n)
                 '()
                 (f v ($fxsub1 n) '())))
-          (error 'vector->list "not a vector" v))))
+          (die 'vector->list "not a vector" v))))
 
   (define list->vector
     (letrec ([race
@@ -116,13 +116,13 @@
                       (if (pair? h)
                           (if (not (eq? h t))
                               (race ($cdr h) ($cdr t) ls ($fx+ n 2))
-                              (error 'list->vector "circular list" ls))
+                              (die 'list->vector "circular list" ls))
                           (if (null? h)
                               ($fx+ n 1)
-                              (error 'list->vector "not a proper list" ls))))
+                              (die 'list->vector "not a proper list" ls))))
                    (if (null? h)
                        n
-                       (error 'list->vector "not a proper list" ls))))]
+                       (die 'list->vector "not a proper list" ls))))]
               [fill
                (lambda (v i ls)
                  (cond
@@ -152,9 +152,9 @@
       (case-lambda
         [(p v) 
          (unless (procedure? p) 
-           (error who "not a procedure" p))
+           (die who "not a procedure" p))
          (unless (vector? v) 
-           (error who "not a vector" v))
+           (die who "not a vector" v))
          (let f ([p p] [v v] [i 0] [n (vector-length v)] [ac '()])
            (cond
              [($fx= i n) (ls->vec ac n)]
@@ -162,14 +162,14 @@
               (f p v ($fxadd1 i) n (cons (p (vector-ref v i)) ac))]))]
         [(p v0 v1) 
          (unless (procedure? p) 
-           (error who "not a procedure" p))
+           (die who "not a procedure" p))
          (unless (vector? v0) 
-           (error who "not a vector" v0))
+           (die who "not a vector" v0))
          (unless (vector? v1) 
-           (error who "not a vector" v1))
+           (die who "not a vector" v1))
          (let ([n (vector-length v0)])
            (unless ($fx= n ($vector-length v1))
-             (error who "length mismatch" v0 v1))
+             (die who "length mismatch" v0 v1))
            (let f ([p p] [v0 v0] [v1 v1] [i 0] [n n] [ac '()])
              (cond
                [($fx= i n) (ls->vec ac n)]
@@ -178,21 +178,21 @@
                    (cons (p ($vector-ref v0 i) ($vector-ref v1 i)) ac))])))]
         [(p v0 v1 . v*) 
          (unless (procedure? p) 
-           (error who "not a procedure" p))
+           (die who "not a procedure" p))
          (unless (vector? v0) 
-           (error who "not a vector" v0))
+           (die who "not a vector" v0))
          (unless (vector? v1) 
-           (error who "not a vector" v1))
+           (die who "not a vector" v1))
          (let ([n (vector-length v0)])
            (unless ($fx= n ($vector-length v1))
-             (error who "length mismatch" v0 v1))
+             (die who "length mismatch" v0 v1))
            (let f ([v* v*] [n n])
              (unless (null? v*) 
                (let ([a ($car v*)])
                  (unless (vector? a) 
-                   (error who "not a vector" a))
+                   (die who "not a vector" a))
                  (unless ($fx= ($vector-length a) n) 
-                   (error who "length mismatch")))
+                   (die who "length mismatch")))
                (f ($cdr v*) n)))
            (let f ([p p] [v0 v0] [v1 v1] [v* v*] [i 0] [n n] [ac '()])
              (cond
@@ -215,9 +215,9 @@
       (case-lambda
         [(p v) 
          (unless (procedure? p) 
-           (error who "not a procedure" p))
+           (die who "not a procedure" p))
          (unless (vector? v) 
-           (error who "not a vector" v))
+           (die who "not a vector" v))
          (let f ([p p] [v v] [i 0] [n (vector-length v)])
            (cond
              [($fx= i n) (void)]
@@ -226,14 +226,14 @@
               (f p v ($fxadd1 i) n)]))]
         [(p v0 v1) 
          (unless (procedure? p) 
-           (error who "not a procedure" p))
+           (die who "not a procedure" p))
          (unless (vector? v0) 
-           (error who "not a vector" v0))
+           (die who "not a vector" v0))
          (unless (vector? v1) 
-           (error who "not a vector" v1))
+           (die who "not a vector" v1))
          (let ([n (vector-length v0)])
            (unless ($fx= n ($vector-length v1))
-             (error who "length mismatch" v0 v1))
+             (die who "length mismatch" v0 v1))
            (let f ([p p] [v0 v0] [v1 v1] [i 0] [n n])
              (cond
                [($fx= i n) (void)]
@@ -242,21 +242,21 @@
                 (f p v0 v1 ($fxadd1 i) n)])))]
         [(p v0 v1 . v*) 
          (unless (procedure? p) 
-           (error who "not a procedure" p))
+           (die who "not a procedure" p))
          (unless (vector? v0) 
-           (error who "not a vector" v0))
+           (die who "not a vector" v0))
          (unless (vector? v1) 
-           (error who "not a vector" v1))
+           (die who "not a vector" v1))
          (let ([n (vector-length v0)])
            (unless ($fx= n ($vector-length v1))
-             (error who "length mismatch" v0 v1))
+             (die who "length mismatch" v0 v1))
            (let f ([v* v*] [n n])
              (unless (null? v*) 
                (let ([a ($car v*)])
                  (unless (vector? a) 
-                   (error who "not a vector" a))
+                   (die who "not a vector" a))
                  (unless ($fx= ($vector-length a) n) 
-                   (error who "length mismatch")))
+                   (die who "length mismatch")))
                (f ($cdr v*) n)))
            (let f ([p p] [v0 v0] [v1 v1] [v* v*] [i 0] [n n])
              (cond
@@ -272,7 +272,7 @@
 
   (define (vector-fill! v fill)
     (unless (vector? v) 
-      (error 'vector-fill! "not a vector" v))
+      (die 'vector-fill! "not a vector" v))
     (let f ([v v] [i 0] [n ($vector-length v)] [fill fill])
       (unless ($fx= i n) 
         ($vector-set! v i fill)
diff --git a/scheme/ikarus.writer.ss b/scheme/ikarus.writer.ss
index 6e28834..7851c7c 100644
--- a/scheme/ikarus.writer.ss
+++ b/scheme/ikarus.writer.ss
@@ -334,7 +334,7 @@
          (write-char #\. p)
          (write-char #\. p)
          (write-char #\. p)]
-        [else (error 'write-peculiear "BUG")])))
+        [else (die 'write-peculiear "BUG")])))
 
   (define write-symbol
     (lambda (x p m)
@@ -721,7 +721,7 @@
         (cond
           [(fx= i (string-length fmt))
            (unless (null? args) 
-             (error who 
+             (die who 
                (format 
                  "extra arguments given for format string \x2036;~a\x2033;"
                  fmt)))]
@@ -731,30 +731,30 @@
                [(eqv? c #\~)
                 (let ([i (fxadd1 i)])
                   (when (fx= i (string-length fmt))
-                    (error who "invalid ~ at end of format string" fmt))
+                    (die who "invalid ~ at end of format string" fmt))
                   (let ([c (string-ref fmt i)])
                    (cond
                      [(memv c '(#\~ #\%)) (f (fxadd1 i) args)]
                      [(memv c '(#\a #\s))
                       (when (null? args)
-                        (error who "insufficient arguments"))
+                        (die who "insufficient arguments"))
                       (f (fxadd1 i) (cdr args))]
                      [(memv c '(#\b #\o #\x #\d))
                       (when (null? args)
-                        (error who "insufficient arguments"))
+                        (die who "insufficient arguments"))
                       (let ([a (car args)])
                         (cond
                           [(or (fixnum? a) (bignum? a) (ratnum?  a)) 
                            (void)]
                           [(flonum? a)
                            (unless (eqv? c #\d) 
-                             (error who 
+                             (die who 
                                (format "flonums cannot be printed with ~~~a" c)))]
                           [else 
-                           (error who "not a number" a)]))
+                           (die who "not a number" a)]))
                       (f (fxadd1 i) (cdr args))]
                      [else
-                      (error who "invalid sequence character after ~" c)])))]
+                      (die who "invalid sequence character after ~" c)])))]
                [else (f (fxadd1 i) args)]))]))
       ;;; then format
       (let f ([i 0] [args args])
@@ -787,9 +787,9 @@
                            [(flonum? a)
                             (display-to-port (number->string a) p)]
                            [else 
-                            (error who "BUG: not a number" a)]))
+                            (die who "BUG: not a number" a)]))
                        (f (fxadd1 i) (cdr args)))]
-                    [else (error who "BUG" c)])))]
+                    [else (die who "BUG" c)])))]
               [else 
                (write-char c p)
                (f (fxadd1 i) args)]))))
@@ -799,15 +799,15 @@
   (define fprintf
     (lambda (port fmt . args)
       (unless (output-port? port) 
-        (error 'fprintf "not an output port" port))
+        (die 'fprintf "not an output port" port))
       (unless (string? fmt)
-        (error 'fprintf "not a string" fmt))
+        (die 'fprintf "not a string" fmt))
       (formatter 'fprintf port fmt args)))
 
   (define display-error
     (lambda (errname who fmt args)
       (unless (string? fmt)
-        (error 'print-error "not a string" fmt))
+        (die 'print-error "not a string" fmt))
       (let ([p (standard-error-port)])
         (if who
             (fprintf p "~a in ~a: " errname who)
@@ -819,7 +819,7 @@
   (define format
     (lambda (fmt . args)
       (unless (string? fmt)
-        (error 'format "not a string" fmt))
+        (die 'format "not a string" fmt))
       (let-values ([(p e) (open-string-output-port)])
         (formatter 'format p fmt args)
         (e))))
@@ -827,7 +827,7 @@
   (define printf 
     (lambda (fmt . args)
       (unless (string? fmt)
-        (error 'printf "not a string" fmt))
+        (die 'printf "not a string" fmt))
       (formatter 'printf (current-output-port) fmt args)))
   
   (define write 
@@ -835,12 +835,12 @@
       [(x) (write-to-port x (current-output-port))]
       [(x p)
        (unless (output-port? p) 
-         (error 'write "not an output port" p))
+         (die 'write "not an output port" p))
        (write-to-port x p)]))
 
   (define (put-datum p x)
     (unless (output-port? p) 
-      (error 'put-datum "not an output port" p))
+      (die 'put-datum "not an output port" p))
     (write-to-port x p))
 
   (define display 
@@ -848,7 +848,7 @@
       [(x) (display-to-port x (current-output-port))]
       [(x p)
        (unless (output-port? p) 
-         (error 'display "not an output port" p))
+         (die 'display "not an output port" p))
        (display-to-port x p)]))
 
   (define print-error 
diff --git a/scheme/makefile.ss b/scheme/makefile.ss
index b740e66..d3c5cb4 100755
--- a/scheme/makefile.ss
+++ b/scheme/makefile.ss
@@ -659,6 +659,7 @@
     [equal?                                      i r ba se]
     [eqv?                                        i r ba se]
     [error                                       i r ba]
+    [die                                         i]
     [even?                                       i r ba se]
     [exact                                       i r ba]
     [exact-integer-sqrt                          i r ba]
diff --git a/scheme/psyntax.expander.ss b/scheme/psyntax.expander.ss
index 815206c..e102670 100644
--- a/scheme/psyntax.expander.ss
+++ b/scheme/psyntax.expander.ss
@@ -76,7 +76,7 @@
       (cond
         ((symbol? sym) (gensym sym))
         ((stx? sym) (gen-lexical (id->sym sym)))
-        (else (error 'gen-lexical "BUG: invalid arg" sym)))))
+        (else (assertion-violation 'gen-lexical "BUG: invalid arg" sym)))))
   
   ;;; gen-global is used to generate global names (e.g. locations
   ;;; for library exports).  We use gen-lexical since it works just 
@@ -117,7 +117,7 @@
                (car label*)
                (find sym mark* (cdr sym*) (cdr mark**) (cdr label*)))))
     (when (rib-sealed/freq rib)
-      (error 'extend-rib! "rib is sealed" rib))
+      (assertion-violation 'extend-rib! "rib is sealed" rib))
     (let ((sym (id->sym id))
           (mark* (stx-mark* id)))
       (let ((sym* (rib-sym* rib)))
@@ -127,7 +127,7 @@
            =>
            (lambda (label^) 
              (unless (eq? label label^)
-               ;;; signal an error if the identifier was already
+               ;;; signal an assertion-violation if the identifier was already
                ;;; in the rib.
                (stx-error id "cannot redefine")))]
           [else
@@ -347,7 +347,7 @@
                (m* (stx-mark* x)) (s* (stx-subst* x)))
            (map (lambda (x) (mkstx x m* s*)) ls)))
         ((vector? x) (vector->list x))
-        (else (error 'syntax-vector->list "not a syntax vector" x)))))
+        (else (assertion-violation 'syntax-vector->list "not a syntax vector" x)))))
   (define syntax-pair?
     (lambda (x) (syntax-kind? x pair?)))
   (define syntax-vector?
@@ -364,21 +364,21 @@
           (mkstx (syntax-car (stx-expr x)) (stx-mark* x) (stx-subst* x))
           (if (pair? x)
               (car x)
-              (error 'syntax-car "not a pair" x)))))
+              (assertion-violation 'syntax-car "not a pair" x)))))
   (define syntax->list
     (lambda (x)
       (if (syntax-pair? x)
           (cons (syntax-car x) (syntax->list (syntax-cdr x)))
           (if (syntax-null? x)
               '()
-              (error 'syntax->list "invalid argument" x)))))
+              (assertion-violation 'syntax->list "invalid argument" x)))))
   (define syntax-cdr
     (lambda (x)
       (if (stx? x)
           (mkstx (syntax-cdr (stx-expr x)) (stx-mark* x) (stx-subst* x))
           (if (pair? x)
               (cdr x)
-              (error 'syntax-cdr "not a pair" x)))))
+              (assertion-violation 'syntax-cdr "not a pair" x)))))
   (define id?
     (lambda (x) (syntax-kind? x symbol?)))
   
@@ -388,7 +388,7 @@
           (id->sym (stx-expr x))
           (if (symbol? x)
               x
-              (error 'id->sym "not an id" x)))))
+              (assertion-violation 'id->sym "not an id" x)))))
 
   ;;; Two lists of marks are considered the same if they have the 
   ;;; same length and the corresponding marks on each are eq?.
@@ -578,9 +578,9 @@
     (lambda (x)
       (syntax-case x ()
         ((_ stx)
-         (syntax (error 'expander "invalid syntax" (stx->datum stx))))
+         (syntax (assertion-violation 'expander "invalid syntax" (stx->datum stx))))
         ((_ stx msg arg* ...)
-         (syntax (error 'expander msg (strip stx '()) arg* ...))))))
+         (syntax (assertion-violation 'expander msg (strip stx '()) arg* ...))))))
   
   ;;; when the rhs of a syntax definition is evaluated, it should be
   ;;; either a procedure, an identifier-syntax transformer or an
@@ -589,7 +589,7 @@
   ;;;   (lacal-macro . procedure)
   ;;;   (local-macro! . procedure)
   ;;;   ($rtd . $rtd)
-  ;;; and signals an error otherwise.
+  ;;; and signals an assertion-violation otherwise.
   (define sanitize-binding
     (lambda (x src)
       (cond
@@ -598,14 +598,14 @@
         ((and (pair? x) (eq? (car x) 'macro!) (procedure? (cdr x)))
          (cons* 'local-macro! (cdr x) src))
         ((and (pair? x) (eq? (car x) '$rtd)) x)
-        (else (error 'expand "invalid transformer" x)))))
+        (else (assertion-violation 'expand "invalid transformer" x)))))
   
   ;;; r6rs's make-variable-transformer:
   (define make-variable-transformer
     (lambda (x)
       (if (procedure? x)
           (cons 'macro! x)
-          (error 'make-variable-transformer
+          (assertion-violation 'make-variable-transformer
                  "not a procedure" x))))
 
   ;;; make-eval-transformer takes an expanded expression, 
@@ -1111,7 +1111,7 @@
                        (let ((v ,expr))
                          (if (procedure? v)
                              (make-traced-procedure ',who v)
-                             (error 'trace-define
+                             (assertion-violation 'trace-define
                                 "not a procedure" v)))))
              (stx-error stx "invalid name"))))))
   
@@ -1124,7 +1124,7 @@
                        (let ((v ,expr))
                          (if (procedure? v)
                              (make-traced-procedure ',who v syntax->datum)
-                             (error 'trace-define-syntax
+                             (assertion-violation 'trace-define-syntax
                                 "not a procedure" v)))))
              (stx-error stx "invalid name"))))))
 
@@ -1233,7 +1233,7 @@
       (syntax-match stx ()
         ((_ expr)
          (bless `(unless ,expr
-                   (error 'assert "assertion failed" ',expr)))))))
+                   (assertion-violation 'assert "assertion failed" ',expr)))))))
   
   (define endianness-macro
     (lambda (stx)
@@ -1597,7 +1597,7 @@
                                (lambda (x)
                                  (if ($struct/rtd? x ',rtd)
                                      ($struct-ref x ,i)
-                                     (error ',getter
+                                     (assertion-violation ',getter
                                             "not a struct of required type"
                                             x ',rtd)))))
                          getters i*)
@@ -1606,7 +1606,7 @@
                                (lambda (x v)
                                  (if ($struct/rtd? x ',rtd)
                                      ($struct-set! x ,i v)
-                                     (error ',setter
+                                     (assertion-violation ',setter
                                             "not a struct of required type"
                                             x ',rtd)))))
                          setters i*)))))))
@@ -1624,7 +1624,7 @@
                      (cond
                        [(symbol? x) (symbol->string x)]
                        [(string? x) x]
-                       [else (error 'define-record-type "BUG")]))
+                       [else (assertion-violation 'define-record-type "BUG")]))
                    str*)))))
       (define (get-record-name spec)
         (syntax-match spec ()
@@ -2011,7 +2011,7 @@
                     (match-empty (vector-ref p 3) r))))
                ((free-id atom) r)
                ((vector) (match-empty (vector-ref p 1) r))
-               (else (error 'syntax-dispatch "invalid pattern" p)))))))
+               (else (assertion-violation 'syntax-dispatch "invalid pattern" p)))))))
       (define combine
         (lambda (r* r)
           (if (null? (car r*))
@@ -2051,7 +2051,7 @@
                ((vector)
                 (and (vector? e)
                      (match (vector->list e) (vector-ref p 1) m* s* r)))
-               (else (error 'syntax-dispatch "invalid pattern" p)))))))
+               (else (assertion-violation 'syntax-dispatch "invalid pattern" p)))))))
       (define match
         (lambda (e p m* s* r)
           (cond
@@ -2334,7 +2334,7 @@
         ((type-descriptor)        type-descriptor-transformer)
         ((record-type-descriptor) record-type-descriptor-transformer)
         ((record-constructor-descriptor) record-constructor-descriptor-transformer)
-        (else (error 'macro-transformer "cannot find transformer" name)))))
+        (else (assertion-violation 'macro-transformer "cannot find transformer" name)))))
   
   (define file-options-macro
     (lambda (x)
@@ -2398,8 +2398,8 @@
              fields mutable immutable parent protocol
              sealed opaque nongenerative parent-rtd)
             incorrect-usage-macro)
-           (else (error 'macro-transformer "invalid macro" x))))
-        (else (error 'core-macro-transformer "invalid macro" x)))))
+           (else (assertion-violation 'macro-transformer "invalid macro" x))))
+        (else (assertion-violation 'core-macro-transformer "invalid macro" x)))))
   
   (define (local-macro-transformer x)
     (car x))
@@ -2424,7 +2424,7 @@
         (let ((transformer
                (cond
                  ((procedure? x) x)
-                 (else (error 'chi-global-macro "not a procedure")))))
+                 (else (assertion-violation 'chi-global-macro "not a procedure")))))
           (let ((s (transformer (add-mark anti-mark e))))
             (add-mark (gen-mark) s))))))
   
@@ -2514,7 +2514,7 @@
            (stx-error e 
              "attempt to reference an unexportable variable"))
           (else
-           ;(error 'chi-expr "invalid type " type (strip e '()))
+           ;(assertion-violation 'chi-expr "invalid type " type (strip e '()))
            (stx-error e "invalid expression"))))))
 
   (define chi-set!
@@ -2600,7 +2600,7 @@
            (build-sequence no-source
              (list (chi-expr expr r mr)
                    (build-void)))))
-        (else (error 'chi-rhs "invalid rhs" rhs)))))
+        (else (assertion-violation 'chi-rhs "invalid rhs" rhs)))))
 
   (define chi-rhs*
     (lambda (rhs* r mr)
@@ -2814,7 +2814,7 @@
                [(local-macro) 'global-macro]
                [(local-macro!) 'global-macro!]
                [else
-                (error 'set-global-macro-binding!
+                (assertion-violation 'set-global-macro-binding!
                   "BUG: invalid type" b)])]
             [transformer (cadr b)]
             [label (id->label id)]
@@ -2868,7 +2868,7 @@
                         (set-global-macro-binding! id loc b)
                         (chi-top* (cdr e*) init*))))))
                ((let-syntax letrec-syntax) 
-                (error 'chi-top* "not supported yet at top level" type))
+                (assertion-violation 'chi-top* "not supported yet at top level" type))
                ((begin)
                 (syntax-match e ()
                   ((_ x* ...)
@@ -2903,7 +2903,7 @@
                                   (else 
                                    (extend-library-subst! lib sym label))))
                               subst-names subst-labels)))
-                         (else (error 'import "BUG: cannot happen"))))])
+                         (else (assertion-violation 'import "BUG: cannot happen"))))])
                   (chi-top* (cdr e*) init*)))
                (else
                 (chi-top* (cdr e*)
@@ -2930,7 +2930,7 @@
         ((null? exp*)
          (let ((id* (map (lambda (x) (mkstx x top-mark* '())) ext*)))
            (unless (valid-bound-ids? id*)
-             (error 'expander "invalid exports" (find-dups id*))))
+             (assertion-violation 'expander "invalid exports" (find-dups id*))))
          (values int* ext*))
         (else
          (syntax-match (car exp*) ()
@@ -2938,11 +2938,11 @@
             (begin
               (unless (and (eq? rename 'rename) (for-all symbol? i*)
                            (for-all symbol? e*))
-                (error 'expander "invalid export specifier" (car exp*)))
+                (assertion-violation 'expander "invalid export specifier" (car exp*)))
               (f (cdr exp*) (append i* int*) (append e* ext*))))
            (ie
             (begin
-              (unless (symbol? ie) (error 'expander "invalid export" ie))
+              (unless (symbol? ie) (assertion-violation 'expander "invalid export" ie))
               (f (cdr exp*) (cons ie int*) (cons ie ext*)))))))))
 
   ;;; given a library name, like (foo bar (1 2 3)), 
@@ -2983,7 +2983,7 @@
   ;;;     and  (#<library (foo)> #<library (bar)>)
   (define (parse-import-spec* imp*)
     (define (dup-error name)
-      (error 'import "two imports with different bindings" name))
+      (assertion-violation 'import "two imports with different bindings" name))
     (define (merge-substs s subst)
       (define (insert-to-subst a subst)
         (let ((name (car a)) (label (cdr a)))
@@ -3004,7 +3004,7 @@
       (define (exclude sym subst)
         (cond
           ((null? subst)
-           (error 'import "cannot rename unbound identifier" sym))
+           (assertion-violation 'import "cannot rename unbound identifier" sym))
           ((eq? sym (caar subst))
            (values (cdar subst) (cdr subst)))
           (else
@@ -3021,7 +3021,7 @@
       (map (lambda (x)
              (cond
                ((assq x subst) => cdr)
-               (else (error 'import "cannot find identifier" x))))
+               (else (assertion-violation 'import "cannot find identifier" x))))
            sym*))
     (define (rem* sym* subst)
       (let f ((subst subst))
@@ -3057,7 +3057,7 @@
            (lambda (x) (<= x n))]
           [(p? n) (and (eq? p? '>=) (subversion? n))
            (lambda (x) (>= x n))]
-          [_ (error 'import "invalid sub-version spec" x* spec)]))
+          [_ (assertion-violation 'import "invalid sub-version spec" x* spec)]))
       (define (version-pred x*)
         (syntax-match x* ()
           [() (lambda (x) #t)]
@@ -3082,7 +3082,7 @@
                    [else 
                     (and ((car p*) (car x)) 
                          (f (cdr p*) (cdr x*)))]))))]
-          [_ (error 'import "invalid version spec" x* spec)]))
+          [_ (assertion-violation 'import "invalid version spec" x* spec)]))
       (let f ([x spec])
         (syntax-match x ()
           [((version-spec* ...)) 
@@ -3130,14 +3130,14 @@
          ;;; FIXME: versioning stuff
          (let-values ([(name pred) (parse-library-name spec*)])
            (when (null? name) 
-             (error 'import "empty library name" spec*))
+             (assertion-violation 'import "empty library name" spec*))
            (let ((lib (find-library-by-name name)))
              (unless lib
-               (error 'import 
+               (assertion-violation 'import 
                   "cannot find library with required name"
                   name))
              (unless (pred (library-version lib))
-               (error 'import 
+               (assertion-violation 'import 
                   "library does not satisfy version specification"
                   lib
                   spec*))
@@ -3146,7 +3146,7 @@
         ((x x* ...)
          (not (memq x '(rename except only prefix library)))
          (get-import `(library (,x . ,x*))))
-        (spec (error 'import "invalid import spec" spec))))
+        (spec (assertion-violation 'import "invalid import spec" spec))))
     (define (add-imports! imp h)
       (let ([subst (get-import imp)])
         (for-each
@@ -3193,28 +3193,28 @@
   (define inv-collector
     (make-parameter
       (lambda args
-        (error 'inv-collector "not initialized"))
+        (assertion-violation 'inv-collector "not initialized"))
       (lambda (x)
         (unless (procedure? x)
-          (error 'inv-collector "not a procedure" x))
+          (assertion-violation 'inv-collector "not a procedure" x))
         x)))
   
   (define vis-collector
     (make-parameter
       (lambda args
-        (error 'vis-collector "not initialized"))
+        (assertion-violation 'vis-collector "not initialized"))
       (lambda (x)
         (unless (procedure? x)
-          (error 'vis-collector "not a procedure" x))
+          (assertion-violation 'vis-collector "not a procedure" x))
         x)))
   
   (define imp-collector
     (make-parameter
       (lambda args
-        (error 'imp-collector "not initialized"))
+        (assertion-violation 'imp-collector "not initialized"))
       (lambda (x)
         (unless (procedure? x)
-          (error 'imp-collector "not a procedure" x))
+          (assertion-violation 'imp-collector "not a procedure" x))
         x)))
 
   (define chi-library-internal
@@ -3258,7 +3258,7 @@
                                     (let ([b (cdr p)])
                                       (let ([type (car b)])
                                         (when (eq? type 'mutable)
-                                          (error 'export errstr name))))))))
+                                          (assertion-violation 'export errstr name))))))))
                             export-subst)
                           (let ((invoke-body
                                  (build-library-letrec* no-source
@@ -3295,10 +3295,10 @@
       (((import imp* ...) b* ...) (eq? import 'import)
        (values imp* b*))
       (((import . x) . y) (eq? import 'import)
-       (error 'expander 
+       (assertion-violation 'expander 
          "invalid syntax of top-level program"))
       (_ 
-       (error 'expander 
+       (assertion-violation 'expander 
          "top-level program is missing an (import ---) clause"))))
 
   (define top-level-expander
@@ -3314,7 +3314,7 @@
   (define-record env (names labels itc)
     (lambda (x p)
       (unless (env? x)
-        (error 'record-type-printer "not an environment"))
+        (assertion-violation 'record-type-printer "not an environment"))
       (display "#<environment>" p)))
   
   (define environment?
@@ -3335,11 +3335,11 @@
   ;;; constructed simply using the corresponding libraries.
   (define (null-environment n)
     (unless (eqv? n 5)
-      (error 'null-environment "not 5" n))
+      (assertion-violation 'null-environment "not 5" n))
     (environment '(psyntax null-environment-5)))
   (define (scheme-report-environment n)
     (unless (eqv? n 5)
-      (error 'scheme-report-environment "not 5" n))
+      (assertion-violation 'scheme-report-environment "not 5" n))
     (environment '(psyntax scheme-report-environment-5)))
 
   ;;; The expand procedure is the interface to the internal expression
@@ -3349,7 +3349,7 @@
   (define expand
     (lambda (x env)
       (unless (env? env)
-        (error 'expand "not an environment" env))
+        (assertion-violation 'expand "not an environment" env))
       (let ((rib (make-top-rib (env-names env) (env-labels env))))
         (let ((x (mkstx x top-mark* (list rib)))
               (itc (env-itc env))
@@ -3369,7 +3369,7 @@
   (define eval
     (lambda (x env)
       (unless (env? env)
-        (error 'eval "not an environment" env))
+        (assertion-violation 'eval "not an environment" env))
       (let-values (((x invoke-req*) (expand x env)))
         (for-each invoke-library invoke-req*)
         (eval-core (expanded->core x)))))
@@ -3450,7 +3450,7 @@
            (if (eq? x (car lex*)) 
                (car loc*)
                (f x (cdr lex*) (cdr loc*)))]
-          [else (error 'lookup-make-export "BUG")])))
+          [else (assertion-violation 'lookup-make-export "BUG")])))
     (let f ((r r) (env '()) (global* '()) (macro* '()))
       (cond
         ((null? r) (values env global* macro*))
@@ -3482,7 +3482,7 @@
                      (cons (cons loc (binding-value b)) macro*))))
                (($rtd $module) (f (cdr r) (cons x env) global* macro*))
                (else
-                (error 'expander "BUG: do not know how to export"
+                (assertion-violation 'expander "BUG: do not know how to export"
                        (binding-type b) (binding-value b))))))))))
   
   (define generate-temporaries
@@ -3499,28 +3499,28 @@
                   top-mark* '()))
               ls))
         (_ 
-         (error 'generate-temporaries "not a list")))))
+         (assertion-violation 'generate-temporaries "not a list")))))
   
   (define free-identifier=?
     (lambda (x y)
       (if (id? x)
           (if (id? y)
               (free-id=? x y)
-              (error 'free-identifier=? "not an identifier" y))
-          (error 'free-identifier=? "not an identifier" x))))
+              (assertion-violation 'free-identifier=? "not an identifier" y))
+          (assertion-violation 'free-identifier=? "not an identifier" x))))
   
   (define bound-identifier=?
     (lambda (x y)
       (if (id? x)
           (if (id? y)
               (bound-id=? x y)
-              (error 'bound-identifier=? "not an identifier" y))
-          (error 'bound-identifier=? "not an identifier" x))))
+              (assertion-violation 'bound-identifier=? "not an identifier" y))
+          (assertion-violation 'bound-identifier=? "not an identifier" x))))
   
   (define syntax-error
     (lambda (x . args)
       (unless (for-all string? args)
-        (error 'syntax-error "invalid argument" args))
+        (assertion-violation 'syntax-error "invalid argument" args))
       (raise 
         (condition 
           (make-message-condition
@@ -3537,7 +3537,7 @@
        (syntax-violation who msg form #f)]
       [(who msg form subform) 
        (unless (string? msg) 
-         (error 'syntax-violation "message is not a string" msg))
+         (assertion-violation 'syntax-violation "message is not a string" msg))
        (let ([who
               (cond
                 [(or (string? who) (symbol? who)) who]
@@ -3547,7 +3547,7 @@
                    [(id . rest) (id? id) (syntax->datum id)]
                    [_  #f])]
                 [else
-                 (error 'syntax-violation 
+                 (assertion-violation 'syntax-violation 
                     "invalid who argument" who)])])
          (raise 
            (condition
@@ -3565,7 +3565,7 @@
     (lambda (id datum)
       (if (id? id)
           (datum->stx id datum)
-          (error 'datum->syntax "not an identifier" id))))
+          (assertion-violation 'datum->syntax "not an identifier" id))))
   
   (define syntax->datum
     (lambda (x) (stx->datum x)))
diff --git a/scheme/psyntax.library-manager.ss b/scheme/psyntax.library-manager.ss
index ebc718e..5bbd29f 100644
--- a/scheme/psyntax.library-manager.ss
+++ b/scheme/psyntax.library-manager.ss
@@ -44,14 +44,14 @@
     (make-parameter (make-collection)
       (lambda (x)
         (unless (procedure? x)
-          (error 'current-library-collection "not a procedure" x))
+          (assertion-violation 'current-library-collection "not a procedure" x))
         x)))
 
   (define-record library 
     (id name version imp* vis* inv* subst env visit-state invoke-state visible?)
     (lambda (x p)
       (unless (library? x)
-        (error 'record-type-printer "not a library"))
+        (assertion-violation 'record-type-printer "not a library"))
       (display 
         (format "#<library ~s>" 
           (if (null? (library-version x))
@@ -62,7 +62,7 @@
   (define (find-dependencies ls)
     (cond
       ((null? ls) '())
-      (else (error 'find-dependencies "cannot handle deps yet"))))
+      (else (assertion-violation 'find-dependencies "cannot handle deps yet"))))
 
   (define (find-library-by pred)
     (let f ((ls ((current-library-collection))))
@@ -77,7 +77,7 @@
       (lambda (x)
         (if (and (list? x) (for-all string? x))
             (map (lambda (x) x) x)
-            (error 'library-path "not a list of strings" x)))))
+            (assertion-violation 'library-path "not a list of strings" x)))))
   
   (define (library-name->file-name x)
     (let-values (((p extract) (open-string-output-port)))
@@ -141,7 +141,7 @@
       (lambda (f)
         (if (procedure? f)
             f
-            (error 'file-locator "not a procedure" f)))))
+            (assertion-violation 'file-locator "not a procedure" f)))))
 
   (define library-locator
     (make-parameter
@@ -152,17 +152,17 @@
       (lambda (f)
         (if (procedure? f)
             f
-            (error 'library-locator 
+            (assertion-violation 'library-locator 
                    "not a procedure" f)))))
 
   (define current-library-expander
     (make-parameter
       (lambda (x)
-        (error 'library-expander "not initialized"))
+        (assertion-violation 'library-expander "not initialized"))
       (lambda (f)
         (if (procedure? f)
             f
-            (error 'library-expander 
+            (assertion-violation 'library-expander 
                    "not a procedure" f)))))
 
   (define external-pending-libraries 
@@ -170,16 +170,16 @@
 
   (define (find-external-library name)
     (when (member name (external-pending-libraries))
-      (error #f "circular attempt to import library was detected" name))
+      (assertion-violation #f "circular attempt to import library was detected" name))
     (parameterize ((external-pending-libraries
                     (cons name (external-pending-libraries))))
       (let ((lib-expr ((library-locator) name)))
         (unless lib-expr 
-          (error #f "cannot find library" name))
+          (assertion-violation #f "cannot find library" name))
         ((current-library-expander) lib-expr)
         (or (find-library-by
               (lambda (x) (equal? (library-name x) name)))
-            (error #f
+            (assertion-violation #f
               "handling external library did not yield the correct library"
                name)))))
           
@@ -197,7 +197,7 @@
     (let ((id (car spec)))
       (or (find-library-by
             (lambda (x) (eq? id (library-id x))))
-          (error #f "cannot find library with required spec" spec))))
+          (assertion-violation #f "cannot find library with required spec" spec))))
 
   (define label->binding-table (make-eq-hashtable))
 
@@ -225,9 +225,9 @@
           (vis-lib* (map find-library-by-spec/die vis*))
           (inv-lib* (map find-library-by-spec/die inv*)))
       (unless (and (symbol? id) (list? name) (list? ver))
-        (error 'install-library "invalid spec with id/name/ver" id name ver))
+        (assertion-violation 'install-library "invalid spec with id/name/ver" id name ver))
       (when (library-exists? name)
-        (error 'install-library "library is already installed" name))
+        (assertion-violation 'install-library "library is already installed" name))
       (let ((lib (make-library id name ver imp-lib* vis-lib* inv-lib* 
                     exp-subst exp-env visit-code invoke-code 
                     visible?)))
@@ -251,10 +251,10 @@
     (let ((invoke (library-invoke-state lib)))
       (when (procedure? invoke)
         (set-library-invoke-state! lib 
-          (lambda () (error 'invoke "circularity detected" lib)))
+          (lambda () (assertion-violation 'invoke "circularity detected" lib)))
         (for-each invoke-library (library-inv* lib))
         (set-library-invoke-state! lib 
-          (lambda () (error 'invoke "first invoke did not return" lib)))
+          (lambda () (assertion-violation 'invoke "first invoke did not return" lib)))
         (invoke)
         (set-library-invoke-state! lib #t))))
 
@@ -263,10 +263,10 @@
     (let ((visit (library-visit-state lib)))
       (when (procedure? visit)
         (set-library-visit-state! lib 
-          (lambda () (error 'visit "circularity detected" lib)))
+          (lambda () (assertion-violation 'visit "circularity detected" lib)))
         (for-each invoke-library (library-vis* lib))
         (set-library-visit-state! lib 
-          (lambda () (error 'invoke "first visit did not return" lib)))
+          (lambda () (assertion-violation 'invoke "first visit did not return" lib)))
         (visit)
         (set-library-visit-state! lib #t))))
 
@@ -288,7 +288,7 @@
   (define library-spec       
     (lambda (x) 
       (unless (library? x)
-        (error 'library-spec "not a library" x))
+        (assertion-violation 'library-spec "not a library" x))
       (list (library-id x) (library-name x) (library-version x)))) 
   )