diff --git a/src/ikarus.boot b/src/ikarus.boot
index f27f305..e6db8c3 100644
Binary files a/src/ikarus.boot and b/src/ikarus.boot differ
diff --git a/src/libaltcogen.ss b/src/libaltcogen.ss
index 9e9b9c2..1c2b905 100644
--- a/src/libaltcogen.ss
+++ b/src/libaltcogen.ss
@@ -917,13 +917,16 @@
     (define (actual-frame-size vars i)
       (define (conflicts? i ls)
         (and (not (null? ls))
-             (or (record-case (car ls)
-                   [(fvar j) (eq? i j)]
-                   [else #f])
+             (or (let f ([x (car ls)])
+                   (record-case x
+                     [(fvar j) (eq? i j)]
+                     [(var) (f (Var x))]
+                     [(nfvar conf loc) (f loc)]
+                     [else #f]))
                  (conflicts? i (cdr ls)))))
       (define (frame-size-ok? i vars)
         (or (null? vars)
-            (and (not (conflicts? i (map Lhs (nfvar-conf (car vars)))))
+            (and (not (conflicts? i (nfvar-conf (car vars))))
                  (frame-size-ok? (fxadd1 i) (cdr vars)))))
       (cond
         [(frame-size-ok? i vars) i]
@@ -1002,7 +1005,7 @@
          (make-conditional (P e0) (T e1) (T e2))]
         [(seq e0 e1) (make-seq (E e0) (T e1))]
         [else (error who "invalid tail ~s" x)]))
-    ;(print-graph frame-g)
+    ;(print-code x)
     (T x))
   ;;;
   (define (do-spill sp* g)
@@ -1331,7 +1334,7 @@
   (Program x))
 
 (define (print-code x)
-  (parameterize ([print-gensym 'pretty])
+  (parameterize ([print-gensym '#t])
     (pretty-print (unparse x))))
 
 (define (alt-cogen x)
diff --git a/src/tests/tests-1.5-req.scm b/src/tests/tests-1.5-req.scm
index ee1678c..7c297ba 100644
--- a/src/tests/tests-1.5-req.scm
+++ b/src/tests/tests-1.5-req.scm
@@ -2,172 +2,172 @@
 
 
 (add-tests-with-string-output "$fx+"
-  [($fx+ 1 2) => "3\n"]
-  [($fx+ 1 -2) => "-1\n"]
-  [($fx+ -1 2) => "1\n"]
-  [($fx+ -1 -2) => "-3\n"]
-  [($fx+  536870911 -1) =>  "536870910\n"]
-  [($fx+  536870910  1) =>  "536870911\n"]
-  [($fx+ -536870912  1) => "-536870911\n"]
-  [($fx+ -536870911 0) => "-536870911\n"]
-  [($fx+ -536870911 -1) => "-536870912\n"]
-  [($fx+ 536870911 -536870912) => "-1\n"]
-  [($fx+ 1 ($fx+ 2 3)) => "6\n"]
-  [($fx+ 1 ($fx+ 2 -3)) => "0\n"]
-  [($fx+ 1 ($fx+ -2 3)) => "2\n"]
-  [($fx+ 1 ($fx+ -2 -3)) => "-4\n"]
-  [($fx+ -1 ($fx+ 2 3)) => "4\n"]
-  [($fx+ -1 ($fx+ 2 -3)) => "-2\n"]
-  [($fx+ -1 ($fx+ -2 3)) => "0\n"]
-  [($fx+ -1 ($fx+ -2 -3)) => "-6\n"]
-  [($fx+ ($fx+ 1 2) 3) => "6\n"]
-  [($fx+ ($fx+ 1 2) -3) => "0\n"]
-  [($fx+ ($fx+ 1 -2) 3) => "2\n"]
-  [($fx+ ($fx+ 1 -2) -3) => "-4\n"]
-  [($fx+ ($fx+ -1 2) 3) => "4\n"]
-  [($fx+ ($fx+ -1 2) -3) => "-2\n"]
-  [($fx+ ($fx+ -1 -2) 3) => "0\n"]
-  [($fx+ ($fx+ -1 -2) -3) => "-6\n"]
-  [($fx+ ($fx+ ($fx+ ($fx+ ($fx+ ($fx+ ($fx+ ($fx+ 1 2) 3) 4) 5) 6) 7) 8) 9) => "45\n"]
-  [($fx+ 1 ($fx+ 2 ($fx+ 3 ($fx+ 4 ($fx+ 5 ($fx+ 6 ($fx+ 7 ($fx+ 8 9)))))))) => "45\n"]
+  [(fx+ 1 2) => "3\n"]
+  [(fx+ 1 -2) => "-1\n"]
+  [(fx+ -1 2) => "1\n"]
+  [(fx+ -1 -2) => "-3\n"]
+  [(fx+  536870911 -1) =>  "536870910\n"]
+  [(fx+  536870910  1) =>  "536870911\n"]
+  [(fx+ -536870912  1) => "-536870911\n"]
+  [(fx+ -536870911 0) => "-536870911\n"]
+  [(fx+ -536870911 -1) => "-536870912\n"]
+  [(fx+ 536870911 -536870912) => "-1\n"]
+  [(fx+ 1 (fx+ 2 3)) => "6\n"]
+  [(fx+ 1 (fx+ 2 -3)) => "0\n"]
+  [(fx+ 1 (fx+ -2 3)) => "2\n"]
+  [(fx+ 1 (fx+ -2 -3)) => "-4\n"]
+  [(fx+ -1 (fx+ 2 3)) => "4\n"]
+  [(fx+ -1 (fx+ 2 -3)) => "-2\n"]
+  [(fx+ -1 (fx+ -2 3)) => "0\n"]
+  [(fx+ -1 (fx+ -2 -3)) => "-6\n"]
+  [(fx+ (fx+ 1 2) 3) => "6\n"]
+  [(fx+ (fx+ 1 2) -3) => "0\n"]
+  [(fx+ (fx+ 1 -2) 3) => "2\n"]
+  [(fx+ (fx+ 1 -2) -3) => "-4\n"]
+  [(fx+ (fx+ -1 2) 3) => "4\n"]
+  [(fx+ (fx+ -1 2) -3) => "-2\n"]
+  [(fx+ (fx+ -1 -2) 3) => "0\n"]
+  [(fx+ (fx+ -1 -2) -3) => "-6\n"]
+  [(fx+ (fx+ (fx+ (fx+ (fx+ (fx+ (fx+ (fx+ 1 2) 3) 4) 5) 6) 7) 8) 9) => "45\n"]
+  [(fx+ 1 (fx+ 2 (fx+ 3 (fx+ 4 (fx+ 5 (fx+ 6 (fx+ 7 (fx+ 8 9)))))))) => "45\n"]
 )
  
 (add-tests-with-string-output "$fx-"
-  [($fx- 1 2) => "-1\n"]
-  [($fx- 1 -2) => "3\n"]
-  [($fx- -1 2) => "-3\n"]
-  [($fx- -1 -2) => "1\n"]
-  [($fx- 536870910 -1) => "536870911\n"]
-  [($fx- 536870911 1) => "536870910\n"]
-  [($fx- -536870911 1) => "-536870912\n"]
-  [($fx- -536870912 -1) => "-536870911\n"]
-  [($fx- 1 536870911) => "-536870910\n"]
-  [($fx- -1 536870911) => "-536870912\n"]
-  [($fx- 1 -536870910) => "536870911\n"]
-  [($fx- -1 -536870912) => "536870911\n"]
-  [($fx- 536870911 536870911) => "0\n"]
-  ;[($fx- 536870911 -536870912) => "-1\n"]
-  [($fx- -536870911 -536870912) => "1\n"]
-  [($fx- 1 ($fx- 2 3)) => "2\n"]
-  [($fx- 1 ($fx- 2 -3)) => "-4\n"]
-  [($fx- 1 ($fx- -2 3)) => "6\n"]
-  [($fx- 1 ($fx- -2 -3)) => "0\n"]
-  [($fx- -1 ($fx- 2 3)) => "0\n"]
-  [($fx- -1 ($fx- 2 -3)) => "-6\n"]
-  [($fx- -1 ($fx- -2 3)) => "4\n"]
-  [($fx- -1 ($fx- -2 -3)) => "-2\n"]
-  [($fx- 0 ($fx- -2 -3)) => "-1\n"]
-  [($fx- ($fx- 1 2) 3) => "-4\n"]
-  [($fx- ($fx- 1 2) -3) => "2\n"]
-  [($fx- ($fx- 1 -2) 3) => "0\n"]
-  [($fx- ($fx- 1 -2) -3) => "6\n"]
-  [($fx- ($fx- -1 2) 3) => "-6\n"]
-  [($fx- ($fx- -1 2) -3) => "0\n"]
-  [($fx- ($fx- -1 -2) 3) => "-2\n"]
-  [($fx- ($fx- -1 -2) -3) => "4\n"]
-  [($fx- ($fx- ($fx- ($fx- ($fx- ($fx- ($fx- ($fx- 1 2) 3) 4) 5) 6) 7) 8) 9) => "-43\n"]
-  [($fx- 1 ($fx- 2 ($fx- 3 ($fx- 4 ($fx- 5 ($fx- 6 ($fx- 7 ($fx- 8 9)))))))) => "5\n"]
+  [(fx- 1 2) => "-1\n"]
+  [(fx- 1 -2) => "3\n"]
+  [(fx- -1 2) => "-3\n"]
+  [(fx- -1 -2) => "1\n"]
+  [(fx- 536870910 -1) => "536870911\n"]
+  [(fx- 536870911 1) => "536870910\n"]
+  [(fx- -536870911 1) => "-536870912\n"]
+  [(fx- -536870912 -1) => "-536870911\n"]
+  [(fx- 1 536870911) => "-536870910\n"]
+  [(fx- -1 536870911) => "-536870912\n"]
+  [(fx- 1 -536870910) => "536870911\n"]
+  [(fx- -1 -536870912) => "536870911\n"]
+  [(fx- 536870911 536870911) => "0\n"]
+  ;[(fx- 536870911 -536870912) => "-1\n"]
+  [(fx- -536870911 -536870912) => "1\n"]
+  [(fx- 1 (fx- 2 3)) => "2\n"]
+  [(fx- 1 (fx- 2 -3)) => "-4\n"]
+  [(fx- 1 (fx- -2 3)) => "6\n"]
+  [(fx- 1 (fx- -2 -3)) => "0\n"]
+  [(fx- -1 (fx- 2 3)) => "0\n"]
+  [(fx- -1 (fx- 2 -3)) => "-6\n"]
+  [(fx- -1 (fx- -2 3)) => "4\n"]
+  [(fx- -1 (fx- -2 -3)) => "-2\n"]
+  [(fx- 0 (fx- -2 -3)) => "-1\n"]
+  [(fx- (fx- 1 2) 3) => "-4\n"]
+  [(fx- (fx- 1 2) -3) => "2\n"]
+  [(fx- (fx- 1 -2) 3) => "0\n"]
+  [(fx- (fx- 1 -2) -3) => "6\n"]
+  [(fx- (fx- -1 2) 3) => "-6\n"]
+  [(fx- (fx- -1 2) -3) => "0\n"]
+  [(fx- (fx- -1 -2) 3) => "-2\n"]
+  [(fx- (fx- -1 -2) -3) => "4\n"]
+  [(fx- (fx- (fx- (fx- (fx- (fx- (fx- (fx- 1 2) 3) 4) 5) 6) 7) 8) 9) => "-43\n"]
+  [(fx- 1 (fx- 2 (fx- 3 (fx- 4 (fx- 5 (fx- 6 (fx- 7 (fx- 8 9)))))))) => "5\n"]
 )
 
 (add-tests-with-string-output "$fx*"
-  [($fx* 2 3) => "6\n"]
-  [($fx* 2 -3) => "-6\n"]
-  [($fx* -2 3) => "-6\n"]
-  [($fx* -2 -3) => "6\n"]
-  [($fx* 536870911 1) => "536870911\n"]
-  [($fx* 536870911 -1) => "-536870911\n"]
-  [($fx* -536870912 1) => "-536870912\n"]
-  [($fx* -536870911 -1) => "536870911\n"]
-  [($fx* 2 ($fx* 3 4)) => "24\n"]
-  [($fx* ($fx* 2 3) 4) => "24\n"]
-  [($fx* ($fx* ($fx* ($fx* ($fx* 2 3) 4) 5) 6) 7) => "5040\n"]
-  [($fx* 2 ($fx* 3 ($fx* 4 ($fx* 5 ($fx* 6 7))))) => "5040\n"]
+  [(fx* 2 3) => "6\n"]
+  [(fx* 2 -3) => "-6\n"]
+  [(fx* -2 3) => "-6\n"]
+  [(fx* -2 -3) => "6\n"]
+  [(fx* 536870911 1) => "536870911\n"]
+  [(fx* 536870911 -1) => "-536870911\n"]
+  [(fx* -536870912 1) => "-536870912\n"]
+  [(fx* -536870911 -1) => "536870911\n"]
+  [(fx* 2 (fx* 3 4)) => "24\n"]
+  [(fx* (fx* 2 3) 4) => "24\n"]
+  [(fx* (fx* (fx* (fx* (fx* 2 3) 4) 5) 6) 7) => "5040\n"]
+  [(fx* 2 (fx* 3 (fx* 4 (fx* 5 (fx* 6 7))))) => "5040\n"]
 )
 
 (add-tests-with-string-output "$fxlogand and $fxlogor"
-  [($fxlogor 3 16) => "19\n"]
-  [($fxlogor 3 5)  => "7\n"]
-  [($fxlogor 3 7)  => "7\n"]
-  [($fxlognot ($fxlogor ($fxlognot 7) 1)) => "6\n"]
-  [($fxlognot ($fxlogor 1 ($fxlognot 7))) => "6\n"]
-  [($fxlogand 3 7) => "3\n"]
-  [($fxlogand 3 5) => "1\n"]
-  [($fxlogand 2346 ($fxlognot 2346)) => "0\n"]
-  [($fxlogand ($fxlognot 2346) 2346) => "0\n"]
-  [($fxlogand 2376 2376) => "2376\n"]
+  [(fxlogor 3 16) => "19\n"]
+  [(fxlogor 3 5)  => "7\n"]
+  [(fxlogor 3 7)  => "7\n"]
+  [(fxlognot (fxlogor (fxlognot 7) 1)) => "6\n"]
+  [(fxlognot (fxlogor 1 (fxlognot 7))) => "6\n"]
+  [(fxlogand 3 7) => "3\n"]
+  [(fxlogand 3 5) => "1\n"]
+  [(fxlogand 2346 (fxlognot 2346)) => "0\n"]
+  [(fxlogand (fxlognot 2346) 2346) => "0\n"]
+  [(fxlogand 2376 2376) => "2376\n"]
 )
 
 (add-tests-with-string-output "$fx="
-  [($fx= 12 13) => "#f\n"]
-  [($fx= 12 12) => "#t\n"]
-  [($fx= 16 ($fx+ 13 3)) => "#t\n"]
-  [($fx= 16 ($fx+ 13 13)) => "#f\n"]
-  [($fx= ($fx+ 13 3) 16) => "#t\n"]
-  [($fx= ($fx+ 13 13) 16) => "#f\n"]
+  [(fx= 12 13) => "#f\n"]
+  [(fx= 12 12) => "#t\n"]
+  [(fx= 16 (fx+ 13 3)) => "#t\n"]
+  [(fx= 16 (fx+ 13 13)) => "#f\n"]
+  [(fx= (fx+ 13 3) 16) => "#t\n"]
+  [(fx= (fx+ 13 13) 16) => "#f\n"]
 )
 
 (add-tests-with-string-output "$fx<"
-  [($fx< 12 13) => "#t\n"]
-  [($fx< 12 12) => "#f\n"]
-  [($fx< 13 12) => "#f\n"]
-  [($fx< 16 ($fx+ 13 1)) => "#f\n"]
-  [($fx< 16 ($fx+ 13 3)) => "#f\n"]
-  [($fx< 16 ($fx+ 13 13)) => "#t\n"]
-  [($fx< ($fx+ 13 1) 16) => "#t\n"]
-  [($fx< ($fx+ 13 3) 16) => "#f\n"]
-  [($fx< ($fx+ 13 13) 16) => "#f\n"]
+  [(fx< 12 13) => "#t\n"]
+  [(fx< 12 12) => "#f\n"]
+  [(fx< 13 12) => "#f\n"]
+  [(fx< 16 (fx+ 13 1)) => "#f\n"]
+  [(fx< 16 (fx+ 13 3)) => "#f\n"]
+  [(fx< 16 (fx+ 13 13)) => "#t\n"]
+  [(fx< (fx+ 13 1) 16) => "#t\n"]
+  [(fx< (fx+ 13 3) 16) => "#f\n"]
+  [(fx< (fx+ 13 13) 16) => "#f\n"]
 )
 
 (add-tests-with-string-output "$fx<="
-  [($fx<= 12 13) => "#t\n"]
-  [($fx<= 12 12) => "#t\n"]
-  [($fx<= 13 12) => "#f\n"]
-  [($fx<= 16 ($fx+ 13 1)) => "#f\n"]
-  [($fx<= 16 ($fx+ 13 3)) => "#t\n"]
-  [($fx<= 16 ($fx+ 13 13)) => "#t\n"]
-  [($fx<= ($fx+ 13 1) 16) => "#t\n"]
-  [($fx<= ($fx+ 13 3) 16) => "#t\n"]
-  [($fx<= ($fx+ 13 13) 16) => "#f\n"]
+  [(fx<= 12 13) => "#t\n"]
+  [(fx<= 12 12) => "#t\n"]
+  [(fx<= 13 12) => "#f\n"]
+  [(fx<= 16 (fx+ 13 1)) => "#f\n"]
+  [(fx<= 16 (fx+ 13 3)) => "#t\n"]
+  [(fx<= 16 (fx+ 13 13)) => "#t\n"]
+  [(fx<= (fx+ 13 1) 16) => "#t\n"]
+  [(fx<= (fx+ 13 3) 16) => "#t\n"]
+  [(fx<= (fx+ 13 13) 16) => "#f\n"]
 )
 
 (add-tests-with-string-output "$fx>"
-  [($fx> 12 13) => "#f\n"]
-  [($fx> 12 12) => "#f\n"]
-  [($fx> 13 12) => "#t\n"]
-  [($fx> 16 ($fx+ 13 1)) => "#t\n"]
-  [($fx> 16 ($fx+ 13 3)) => "#f\n"]
-  [($fx> 16 ($fx+ 13 13)) => "#f\n"]
-  [($fx> ($fx+ 13 1) 16) => "#f\n"]
-  [($fx> ($fx+ 13 3) 16) => "#f\n"]
-  [($fx> ($fx+ 13 13) 16) => "#t\n"]
+  [(fx> 12 13) => "#f\n"]
+  [(fx> 12 12) => "#f\n"]
+  [(fx> 13 12) => "#t\n"]
+  [(fx> 16 (fx+ 13 1)) => "#t\n"]
+  [(fx> 16 (fx+ 13 3)) => "#f\n"]
+  [(fx> 16 (fx+ 13 13)) => "#f\n"]
+  [(fx> (fx+ 13 1) 16) => "#f\n"]
+  [(fx> (fx+ 13 3) 16) => "#f\n"]
+  [(fx> (fx+ 13 13) 16) => "#t\n"]
 )
 
 (add-tests-with-string-output "$fx>="
-  [($fx>= 12 13) => "#f\n"]
-  [($fx>= 12 12) => "#t\n"]
-  [($fx>= 13 12) => "#t\n"]
-  [($fx>= 16 ($fx+ 13 1)) => "#t\n"]
-  [($fx>= 16 ($fx+ 13 3)) => "#t\n"]
-  [($fx>= 16 ($fx+ 13 13)) => "#f\n"]
-  [($fx>= ($fx+ 13 1) 16) => "#f\n"]
-  [($fx>= ($fx+ 13 3) 16) => "#t\n"]
-  [($fx>= ($fx+ 13 13) 16) => "#t\n"]
+  [(fx>= 12 13) => "#f\n"]
+  [(fx>= 12 12) => "#t\n"]
+  [(fx>= 13 12) => "#t\n"]
+  [(fx>= 16 (fx+ 13 1)) => "#t\n"]
+  [(fx>= 16 (fx+ 13 3)) => "#t\n"]
+  [(fx>= 16 (fx+ 13 13)) => "#f\n"]
+  [(fx>= (fx+ 13 1) 16) => "#f\n"]
+  [(fx>= (fx+ 13 3) 16) => "#t\n"]
+  [(fx>= (fx+ 13 13) 16) => "#t\n"]
 )
 
 
 (add-tests-with-string-output "if"
-  [(if ($fx= 12 13) 12 13) => "13\n"]
-  [(if ($fx= 12 12) 13 14) => "13\n"]
-  [(if ($fx< 12 13) 12 13) => "12\n"]
-  [(if ($fx< 12 12) 13 14) => "14\n"]
-  [(if ($fx< 13 12) 13 14) => "14\n"]
-  [(if ($fx<= 12 13) 12 13) => "12\n"]
-  [(if ($fx<= 12 12) 12 13) => "12\n"]
-  [(if ($fx<= 13 12) 13 14) => "14\n"]
-  [(if ($fx> 12 13) 12 13) => "13\n"]
-  [(if ($fx> 12 12) 12 13) => "13\n"]
-  [(if ($fx> 13 12) 13 14) => "13\n"]
-  [(if ($fx>= 12 13) 12 13) => "13\n"]
-  [(if ($fx>= 12 12) 12 13) => "12\n"]
-  [(if ($fx>= 13 12) 13 14) => "13\n"]
+  [(if (fx= 12 13) 12 13) => "13\n"]
+  [(if (fx= 12 12) 13 14) => "13\n"]
+  [(if (fx< 12 13) 12 13) => "12\n"]
+  [(if (fx< 12 12) 13 14) => "14\n"]
+  [(if (fx< 13 12) 13 14) => "14\n"]
+  [(if (fx<= 12 13) 12 13) => "12\n"]
+  [(if (fx<= 12 12) 12 13) => "12\n"]
+  [(if (fx<= 13 12) 13 14) => "14\n"]
+  [(if (fx> 12 13) 12 13) => "13\n"]
+  [(if (fx> 12 12) 12 13) => "13\n"]
+  [(if (fx> 13 12) 13 14) => "13\n"]
+  [(if (fx>= 12 13) 12 13) => "13\n"]
+  [(if (fx>= 12 12) 12 13) => "12\n"]
+  [(if (fx>= 13 12) 13 14) => "13\n"]
 )