diff --git a/src/ikarus.boot b/src/ikarus.boot
index a39adde..5f89535 100644
Binary files a/src/ikarus.boot and b/src/ikarus.boot differ
diff --git a/src/ikarus.io.output-files.ss b/src/ikarus.io.output-files.ss
index 7c2293d..4ebad95 100644
--- a/src/ikarus.io.output-files.ss
+++ b/src/ikarus.io.output-files.ss
@@ -4,9 +4,10 @@
           console-output-port current-output-port
           open-output-file with-output-to-file call-with-output-file)
   (import 
-    (only (scheme) $set-port-output-size! $write-char $string-set!
-          $port-output-buffer $set-port-output-index! $fxadd1 $fx<
-          $port-output-size $port-output-index)
+    (ikarus system $ports)
+    (ikarus system $io)
+    (ikarus system $strings)
+    (ikarus system $fx)
     (except (ikarus)
             standard-output-port standard-error-port   
             console-output-port current-output-port    
diff --git a/src/ikarus.multiple-values.ss b/src/ikarus.multiple-values.ss
index bb78478..a361863 100644
--- a/src/ikarus.multiple-values.ss
+++ b/src/ikarus.multiple-values.ss
@@ -1,7 +1,9 @@
 
 (library (ikarus multiple-values)
   (export call-with-values values)
-  (import (except (scheme) call-with-values values))
+  (import 
+    (ikarus system $stack)
+    (except (ikarus) call-with-values values))
 
   (define call-with-values 
     ($make-call-with-values-procedure))
diff --git a/src/ikarus.numerics.ss b/src/ikarus.numerics.ss
index f99a001..3845ebb 100644
--- a/src/ikarus.numerics.ss
+++ b/src/ikarus.numerics.ss
@@ -25,10 +25,9 @@
   (export + - * = < <= > >= add1 sub1 quotient remainder
           quotient+remainder number->string string->number)
   (import 
-    (only (scheme) $fxlogand $fx= $fx< $fx<= $fx> $fx>= $fxzero?
-          $fxsll $fxsra $fxmodulo $string-ref $string-length
-          $fxadd1 $fx- 
-          $char->fixnum $char= $char<=)
+    (ikarus system $fx)
+    (ikarus system $chars)
+    (ikarus system $strings)
     (except (ikarus) + - * = < <= > >= add1 sub1 quotient remainder
             quotient+remainder number->string string->number))
 
diff --git a/src/ikarus.pairs.ss b/src/ikarus.pairs.ss
index dcd0829..38619b6 100644
--- a/src/ikarus.pairs.ss
+++ b/src/ikarus.pairs.ss
@@ -1,16 +1,19 @@
 
 
 (library (ikarus pairs)
-  (export
-    cons weak-cons set-car! set-cdr!
-    car cdr caar cdar cadr cddr caaar cdaar cadar cddar caadr cdadr
-    caddr cdddr caaaar cdaaar cadaar cddaar caadar cdadar caddar
-    cdddar caaadr cdaadr cadadr cddadr caaddr cdaddr cadddr cddddr)
+  (export 
+    cons weak-cons set-car! set-cdr!  car cdr caar cdar cadr cddr
+    caaar cdaar cadar cddar caadr cdadr caddr cdddr caaaar cdaaar
+    cadaar cddaar caadar cdadar caddar cdddar caaadr cdaadr cadadr
+    cddadr caaddr cdaddr cadddr cddddr)
   (import 
-    (only (ikarus) define if lambda pair? error quote let unless
-          foreign-call)
-    (rename (only (scheme) cons $car $cdr $set-car! $set-cdr!)
-            (cons sys:cons)))
+    (except (ikarus) cons weak-cons set-car! set-cdr! car cdr caar
+            cdar cadr cddr caaar cdaar cadar cddar caadr cdadr caddr
+            cdddr caaaar cdaaar cadaar cddaar caadar cdadar caddar
+            cdddar caaadr cdaadr cadadr cddadr caaddr cdaddr cadddr
+            cddddr)
+    (rename (only (ikarus) cons) (cons sys:cons))
+    (ikarus system $pairs))
 
   (define cons (lambda (x y) (sys:cons x y)))
 
diff --git a/src/ikarus.predicates.ss b/src/ikarus.predicates.ss
index 0a73800..25c367b 100644
--- a/src/ikarus.predicates.ss
+++ b/src/ikarus.predicates.ss
@@ -2,20 +2,22 @@
 (library (ikarus predicates)
 
   (export fixnum? flonum? bignum? number? complex? real? rational?
-          integer? exact? eof-object? bwp-object? immediate? boolean?
-          char? vector? string? procedure? null? pair? symbol? not 
-          weak-pair?
-          eq? eqv? equal?) 
+          integer? exact? eof-object? bwp-object? immediate?
+          boolean? char? vector? string? procedure? null? pair?
+          symbol? not weak-pair? eq? eqv? equal?) 
 
   (import 
 
     (except (ikarus) fixnum? flonum? bignum? number? complex? real?
-            rational? integer? exact? eof-object? bwp-object? immediate?
-            boolean? char? vector? string?  procedure? null?
-            pair? weak-pair? symbol? not eq? eqv? equal?
+            rational? integer? exact? eof-object? bwp-object?
+            immediate? boolean? char? vector? string? procedure?
+            null? pair? weak-pair? symbol? not eq? eqv? equal?
             port? input-port? output-port?)
-    (only (scheme) $fxadd1 $vector-ref $fx= $char= $string-ref
-          $string-length $vector-length $car $cdr)
+    (ikarus system $fx)
+    (ikarus system $pairs)
+    (ikarus system $chars)
+    (ikarus system $strings)
+    (ikarus system $vectors)
     (rename (only (ikarus) fixnum? flonum? bignum? eof-object?
                   bwp-object? immediate? boolean? char? vector? string?
                   procedure? null? pair? symbol? eq?
diff --git a/src/ikarus.reader.ss b/src/ikarus.reader.ss
index c15985c..d632954 100644
--- a/src/ikarus.reader.ss
+++ b/src/ikarus.reader.ss
@@ -2,7 +2,7 @@
 (library (ikarus reader)
   (export read read-token comment-handler load)
   (import
-    (only (scheme) $char->fixnum  $char= $char<=)
+    (ikarus system $chars)
     (except (ikarus) read read-token comment-handler load))
 
   (define delimiter?
diff --git a/src/ikarus.records.ss b/src/ikarus.records.ss
index 32b4f2a..1cb7fda 100644
--- a/src/ikarus.records.ss
+++ b/src/ikarus.records.ss
@@ -17,9 +17,7 @@
       record-type-field-names record-constructor record-predicate
       record-field-accessor record-field-mutator record? record-rtd
       record-type-descriptor record-name record-printer record-length
-      record-ref record-set!)
-    (only (scheme)
-          set-top-level-value! top-level-value top-level-bound?))
+      record-ref record-set!))
 
 
 
@@ -102,7 +100,7 @@
        (for-each verify-field fields)
        (let ([g (gensym name)])
          (let ([rtd (make-rtd name fields #f g)])
-           (set-top-level-value! g rtd)
+           (set-symbol-value! g rtd)
            rtd))]
       [(name fields g)
        (unless (string? name)
@@ -111,15 +109,15 @@
          (error 'make-record-type "fields must be a list, got ~s" fields))
        (for-each verify-field fields)
        (cond
-         [(top-level-bound? g)
-          (let ([rtd (top-level-value g)])
+         [(symbol-bound? g)
+          (let ([rtd (symbol-value g)])
             (unless (and (string=? name (record-type-name rtd))
                          (equal? fields (record-type-field-names rtd)))
               (error 'make-record-type "definition mismatch"))
             rtd)]
          [else
           (let ([rtd (make-rtd name fields #f g)])
-            (set-top-level-value! g rtd)
+            (set-symbol-value! g rtd)
             rtd)])]))
 
   (define record-type-name
diff --git a/src/ikarus.strings.ss b/src/ikarus.strings.ss
index e76dca8..d8d4a06 100644
--- a/src/ikarus.strings.ss
+++ b/src/ikarus.strings.ss
@@ -9,12 +9,7 @@
     (ikarus system $pairs)
     (except (ikarus) string-length string-ref string-set! make-string
             string->list string=? string-append substring string
-            list->string uuid)
-    #;(only (scheme) 
-          $fx+ $fxsub1 $fxadd1 $char= $car $cdr
-          $fxzero? $fx= $fx<= $fx< $fx>= $fx-
-          $string-length $string-ref 
-          $make-string $string-set!))
+            list->string uuid))
 
 
   (define string-length
diff --git a/src/ikarus.symbols.ss b/src/ikarus.symbols.ss
index fa08d53..ad8b662 100644
--- a/src/ikarus.symbols.ss
+++ b/src/ikarus.symbols.ss
@@ -6,11 +6,9 @@
           top-level-value top-level-bound? set-top-level-value!
           symbol-value symbol-bound? set-symbol-value!)
   (import 
-    (only (scheme) $make-symbol $symbol-string $set-symbol-string!
-          $symbol-unique-string $set-symbol-unique-string! 
-          $symbol-value $set-symbol-value!
-          $set-symbol-plist! $symbol-plist
-          $car $cdr $fx>= $fxadd1 $set-cdr! $unbound-object?)
+    (ikarus system $symbols)
+    (ikarus system $pairs)
+    (ikarus system $fx)
     (except (ikarus) gensym gensym? gensym->unique-string
       gensym-prefix gensym-count print-gensym
       string->symbol symbol->string
diff --git a/src/makefile.ss b/src/makefile.ss
index 5a7a5ee..b6ef0e3 100755
--- a/src/makefile.ss
+++ b/src/makefile.ss
@@ -483,6 +483,7 @@
       [$set-symbol-string!        $symbols]
       [$set-symbol-unique-string! $symbols]
       [$set-symbol-plist!         $symbols]
+      [$unbound-object?           $symbols]
       ; (ikarus system $records)
       [base-rtd           $records]
       [$record-set!       $records]
@@ -546,7 +547,6 @@
       [$make-values-procedure           $stack]
       ; (ikarus system)
       [$forward-ptr?                    s  ]
-      [$unbound-object?                 s  ]
       [$interrupted?                    s  ]
       [$unset-interrupted!              s  ]
       [$apply-nonprocedure-error-handler s]