diff --git a/src/ikarus.boot b/src/ikarus.boot
index 4168949..08dea6c 100644
Binary files a/src/ikarus.boot and b/src/ikarus.boot differ
diff --git a/src/ikarus.lists.ss b/src/ikarus.lists.ss
index e95ff3c..6665e59 100644
--- a/src/ikarus.lists.ss
+++ b/src/ikarus.lists.ss
@@ -769,7 +769,11 @@
                  #t
                  (error who "length mismatch"))]
             [else (error who "not a list")])]
-         [(f . ls*) (error who "vararg not supported yet in ~s" (length ls*))])))
+         [(f ls . ls*)
+          (unless (procedure? f) 
+            (error who "~s is not a procedure" f))
+          (error who "vararg not yet supported")])))
+
 
 
 
diff --git a/src/ikarus.numerics.ss b/src/ikarus.numerics.ss
index 8d4266c..d8dd70e 100644
--- a/src/ikarus.numerics.ss
+++ b/src/ikarus.numerics.ss
@@ -9,13 +9,15 @@
   (export $flonum->exact $flonum-signed-biased-exponent flonum-parts
           inexact->exact exact $flonum-rational? $flonum-integer? $flzero?
           $flnegative? flpositive? flabs fixnum->flonum
-          flsin flcos fltan flasin flacos flatan)
+          flsin flcos fltan flasin flacos flatan
+          flinteger?)
   (import 
     (ikarus system $bytevectors)
     (except (ikarus system $flonums) $flonum-signed-biased-exponent
             $flonum-rational? $flonum-integer?)
     (except (ikarus) inexact->exact exact flpositive? flabs
-            fixnum->flonum flsin flcos fltan flasin flacos flatan))
+            fixnum->flonum flsin flcos fltan flasin flacos flatan
+            flinteger?))
   
   (define (flonum-bytes f)
     (unless (flonum? f) 
@@ -68,12 +70,18 @@
               (fx= ($flonum-u8-ref x 3) 0) 
               (fx= ($flonum-u8-ref x 2) 0) 
               (fx= ($flonum-u8-ref x 1) 0))]
-        [(fx<= be (fx+ 1075 -52)) ;;; too small to be an integer
+        [(fx< be (fx+ 1075 -52)) ;;; too small to be an integer
          #f]
         [else
          (let ([v ($flonum->exact x)])
            (or (fixnum? v) (bignum? v)))])))
 
+  (define (flinteger? x)
+    (if (flonum? x)
+        ($flonum-integer? x)
+        (error 'flinteger? "~s is not a flonum" x)))
+
+
   (define ($flzero? x)
     (let ([be (fxlogand ($flonum-signed-biased-exponent x) (sub1 (fxsll 1 11)))])
        (and 
diff --git a/src/makefile.ss b/src/makefile.ss
index 46c2f5f..f5c2068 100755
--- a/src/makefile.ss
+++ b/src/makefile.ss
@@ -502,6 +502,7 @@
     [bignum?                 i]
     [ratnum?                 i]
     [integer?                i r]
+    [flinteger?              i]
     [exact?                  i r]
     [inexact?                i r]
     [rational?               i r]
diff --git a/src/todo-r6rs.ss b/src/todo-r6rs.ss
index a8f08f6..383f046 100755
--- a/src/todo-r6rs.ss
+++ b/src/todo-r6rs.ss
@@ -335,7 +335,7 @@
     [flnegative?                                S fl]
     [flnumerator                                S fl]
     [flodd?                                     S fl]
-    [flonum?                                    S fl]
+    [flonum?                                    C fl]
     [flpositive?                                S fl]
     [flround                                    C fl]
     [flsin                                      C fl]