diff --git a/arrays/src/Data/Array.ss b/arrays/src/Data/Array.ss
index b152234e..b5177916 100644
--- a/arrays/src/Data/Array.ss
+++ b/arrays/src/Data/Array.ss
@@ -35,21 +35,21 @@
 
   (define rangeImpl
     (lambda (start end)
-      (let* ([step (if (> start end) -1 1)]
+      (let* ([step (if (fx>? start end) -1 1)]
              [result (srfi:214:make-flexvector (+ (* step (- end start)) 1))])
         (let recur ([i start]
                     [n 0])
-          (if (not (= i end))
+          (if (not (fx=? i end))
             (begin
               (srfi:214:flexvector-set! result n i)
-              (recur (+ i step) (+ n 1)))
+              (recur (fx+ i step) (fx1+ n)))
             (begin
               (srfi:214:flexvector-set! result n i)
               result))))))
 
   (define replicateImpl
     (lambda (count value)
-      (if (< count 1)
+      (if (fx<? count 1)
         (rt:make-array)
         (let ([result (srfi:214:make-flexvector count)])
           (srfi:214:flexvector-fill! result value)
@@ -64,13 +64,13 @@
 
   (define unconsImpl
     (lambda (empty next xs)
-      (if (= (rt:array-length xs) 0)
+      (if (fx=? (rt:array-length xs) 0)
         (empty 'unit)
         ((next (rt:array-ref xs 0)) (srfi:214:flexvector-copy xs 1)))))
 
   (define indexImpl
     (lambda (just nothing xs i)
-      (if (or (< i 0) (>= i (rt:array-length xs)))
+      (if (or (fx<? i 0) (fx>=? i (rt:array-length xs)))
         nothing
         (just (rt:array-ref xs i)))))
 
@@ -78,11 +78,11 @@
     (lambda (nothing isJust f xs)
       (let ([len (rt:array-length xs)])
         (let recur ([i 0])
-          (if (< i len)
+          (if (fx<? i len)
             (let ([result (f (rt:array-ref xs i))])
               (if (isJust result)
                 result
-                (recur (+ i 1))))
+                (recur (fx1+ i))))
             nothing)))))
 
   (define findIndexImpl
@@ -101,7 +101,7 @@
 
   (define _insertAt
     (lambda (just nothing i a l)
-      (if (or (< i 0) (> i (rt:array-length l)))
+      (if (or (fx<? i 0) (fx>? i (rt:array-length l)))
         nothing
         (let ([l1 (srfi:214:flexvector-copy l)])
           (srfi:214:flexvector-add! l1 i a)
@@ -109,7 +109,7 @@
 
   (define _deleteAt
     (lambda (just nothing i l)
-      (if (or (< i 0) (>= i (rt:array-length l)))
+      (if (or (fx<? i 0) (fx>=? i (rt:array-length l)))
         nothing
         (let ([l1 (srfi:214:flexvector-copy l)])
           (srfi:214:flexvector-remove! l1 i)
@@ -117,7 +117,7 @@
 
   (define _updateAt
     (lambda (just nothing i a l)
-      (if (or (< i 0) (>= i (rt:array-length l)))
+      (if (or (fx<? i 0) (fx>=? i (rt:array-length l)))
         nothing
         (let ([l1 (srfi:214:flexvector-copy l)])
           (srfi:214:flexvector-set! l1 i a)
@@ -147,22 +147,22 @@
              [out (srfi:214:make-flexvector len)])
         (let recur ([i 0]
                     [acc b])
-          (if (< i len)
+          (if (fx<? i len)
             (let ([next ((f acc) (rt:array-ref xs i))])
               (srfi:214:flexvector-set! out i next)
-              (recur (+ i 1) next))
+              (recur (fx1+ i) next))
             out)))))
 
   (define scanrImpl
     (lambda (f b xs)
       (let* ([len (rt:array-length xs)]
              [out (srfi:214:make-flexvector len)])
-        (let recur ([i (- len 1)]
+        (let recur ([i (fx1- len)]
                     [acc b])
-          (if (>= i 0)
+          (if (fx>=? i 0)
             (let ([next ((f (rt:array-ref xs i)) acc)])
               (srfi:214:flexvector-set! out i next)
-              (recur (- i 1) next))
+              (recur (fx1- i) next))
             out)))))
 
 ;;------------------------------------------------------------------------------
@@ -173,7 +173,7 @@
     (lambda (compare fromOrdering xs)
       (let ([tmp (srfi:214:flexvector->vector xs)])
         (vector-sort!
-          (lambda (x y) (> (fromOrdering ((compare y) x)) 0))
+          (lambda (x y) (fx>? (fromOrdering ((compare y) x)) 0))
           tmp)
         (srfi:214:vector->flexvector tmp))))
 
@@ -184,7 +184,7 @@
 
   (define sliceImpl
     (lambda (s e l)
-      (if (> s e)
+      (if (fx>? s e)
         (rt:make-array)
         (srfi:214:flexvector-copy l s e))))
 
diff --git a/arrays/src/Data/Array/ST.ss b/arrays/src/Data/Array/ST.ss
index 8d431aec..e521133c 100644
--- a/arrays/src/Data/Array/ST.ss
+++ b/arrays/src/Data/Array/ST.ss
@@ -27,19 +27,19 @@
 
   (define pokeImpl
     (lambda (i a xs)
-      (let ([ret (and (>= i 0) (< i (rt:array-length xs)))])
+      (let ([ret (and (fx>=? i 0) (fx<? i (rt:array-length xs)))])
         (if ret (srfi:214:flexvector-set! xs i a))
         ret)))
 
   (define peekImpl
     (lambda (just nothing i xs)
-      (if (and (>= i 0) (< i (rt:array-length xs)))
+      (if (and (fx>=? i 0) (fx<? i (rt:array-length xs)))
         (just (rt:array-ref xs i))
         nothing)))
 
   (define popImpl
     (lambda (just nothing xs)
-      (if (> (rt:array-length xs) 0)
+      (if (fx>? (rt:array-length xs) 0)
         (just (srfi:214:flexvector-remove-back! xs))
         nothing)))
 
@@ -50,16 +50,16 @@
 
   (define shiftImpl
     (lambda (just nothing xs)
-      (if (> (rt:array-length xs) 0)
+      (if (fx>? (rt:array-length xs) 0)
         (just (srfi:214:flexvector-remove-front! xs))
         nothing)))
 
   (define spliceImpl
     (lambda (i howMany bs xs)
-      (if (> howMany 0)
+      (if (fx>? howMany 0)
         (let ([removed (srfi:214:make-flexvector howMany)])
-          (srfi:214:flexvector-copy! removed 0 xs i (+ i howMany))
-          (srfi:214:flexvector-remove-range! xs i (+ i howMany))
+          (srfi:214:flexvector-copy! removed 0 xs i (fx+ i howMany))
+          (srfi:214:flexvector-remove-range! xs i (fx+ i howMany))
           (srfi:214:flexvector-add-all! xs i (srfi:214:flexvector->list bs))
           removed)
         (begin
@@ -89,7 +89,7 @@
     (lambda (compare fromOrdering xs)
       (let ([tmp (srfi:214:flexvector->vector xs)])
         (vector-sort!
-          (lambda (x y) (> (fromOrdering ((compare y) x)) 0))
+          (lambda (x y) (fx>? (fromOrdering ((compare y) x)) 0))
           tmp)
         (srfi:214:flexvector-copy! xs 0 (srfi:214:vector->flexvector tmp)))))
 
diff --git a/foldable-traversable/test/Main.ss b/foldable-traversable/test/Main.ss
index 29f035ff..9fd2e8cb 100644
--- a/foldable-traversable/test/Main.ss
+++ b/foldable-traversable/test/Main.ss
@@ -3,14 +3,14 @@
           arrayReplicate
           mkNEArray
           foldMap1NEArray)
-  (import (only (rnrs base) define lambda let if + > <)
+  (import (chezscheme)
           (prefix (purs runtime) rt:)
           (prefix (purs runtime srfi :214) srfi:214:))
 
   (define arrayFrom1UpTo
     (lambda (n)
       (srfi:214:flexvector-map/index
-        (lambda (i x) (+ i 1))
+        (lambda (i x) (fx1+ i))
         (srfi:214:make-flexvector n))))
 
   (define arrayReplicate
@@ -23,7 +23,7 @@
     (lambda (nothing)
       (lambda (just)
         (lambda (arr)
-          (if (> (srfi:214:flexvector-length arr) 0)
+          (if (fx>? (srfi:214:flexvector-length arr) 0)
             (just arr)
             nothing)))))
 
@@ -34,8 +34,8 @@
           (let ([len (srfi:214:flexvector-length arr)])
             (let recur ([acc (f (rt:array-ref arr 0))]
                         [i 1])
-              (if (< i len)
-                (recur ((append acc) (f (rt:array-ref arr i))) (+ i 1))
+              (if (fx<? i len)
+                (recur ((append acc) (f (rt:array-ref arr i))) (fx1+ i))
                 acc)))))))
 
 )
diff --git a/prelude/src/Control/Bind.ss b/prelude/src/Control/Bind.ss
index 7beae5ff..18d70ab7 100644
--- a/prelude/src/Control/Bind.ss
+++ b/prelude/src/Control/Bind.ss
@@ -2,7 +2,7 @@
 
 (library (Control.Bind foreign)
   (export arrayBind)
-  (import (only (rnrs base) define lambda if = + begin let)
+  (import (chezscheme)
           (prefix (purs runtime) rt:)
           (prefix (purs runtime srfi :214) srfi:214:))
 
@@ -12,10 +12,10 @@
         (let ([len (rt:array-length arr)]
               [result (srfi:214:flexvector)])
           (let loop ([i 0])
-            (if (= i len)
+            (if (fx=? i len)
               result
               (begin
                 (srfi:214:flexvector-append! result (f (rt:array-ref arr i)))
-                (loop (+ i 1)))))))))
+                (loop (fx1+ i)))))))))
 
 )
diff --git a/prelude/src/Data/Eq.ss b/prelude/src/Data/Eq.ss
index 593c8366..270cb6cd 100644
--- a/prelude/src/Data/Eq.ss
+++ b/prelude/src/Data/Eq.ss
@@ -20,12 +20,12 @@
   (define eqIntImpl
     (lambda (r1)
       (lambda (r2)
-        (= r1 r2))))
+        (fx=? r1 r2))))
 
   (define eqNumberImpl
     (lambda (r1)
       (lambda (r2)
-        (= r1 r2))))
+        (fl=? r1 r2))))
 
   (define eqCharImpl
     (lambda (r1)
diff --git a/prelude/src/Data/Ord.ss b/prelude/src/Data/Ord.ss
index 72c9f58b..b359886f 100644
--- a/prelude/src/Data/Ord.ss
+++ b/prelude/src/Data/Ord.ss
@@ -7,8 +7,7 @@
           ordStringImpl
           ordCharImpl
           ordArrayImpl)
-  (import (chezscheme))
-  (import (only (rnrs base) define lambda)
+  (import (chezscheme)
           (only (purs runtime pstring) pstring<? pstring=?)
           (prefix (purs runtime srfi :214) srfi:214:))
 
@@ -28,9 +27,9 @@
         (lambda (gt)
           (lambda (x)
             (lambda (y)
-              (if (< x y)
+              (if (fx<? x y)
                   lt
-                  (if (= x y) eq gt))))))))
+                  (if (fx=? x y) eq gt))))))))
 
   (define ordNumberImpl
     (lambda (lt)
@@ -38,9 +37,9 @@
         (lambda (gt)
           (lambda (x)
             (lambda (y)
-              (if (< x y)
+              (if (fl<? x y)
                   lt
-                  (if (= x y) eq gt))))))))
+                  (if (fl=? x y) eq gt))))))))
 
   (define ordStringImpl
     (lambda (lt)
@@ -70,15 +69,15 @@
                 [ylen (srfi:214:flexvector-length ys)])
              (let loop ([xsi 0]
                         [ysi 0])
-               (if (or (= xsi xlen) (= ysi ylen))
+               (if (or (fx=? xsi xlen) (fx=? ysi ylen))
                  (cond
-                   [(= xlen ylen) 0]
-                   [(> xlen ylen) -1]
+                   [(fx=? xlen ylen) 0]
+                   [(fx>? xlen ylen) -1]
                    (else 1))
                  (let ([o ((f (srfi:214:flexvector-ref xs xsi)) (srfi:214:flexvector-ref ys ysi))])
                    (if (not (fx=? o 0))
                      o
                      (loop
-                       (+ xsi 1)
-                       (+ ysi 1)))))))))))
+                       (fx1+ xsi)
+                       (fx1+ ysi)))))))))))
 )
diff --git a/prelude/src/Data/Show.ss b/prelude/src/Data/Show.ss
index ccfa4522..4208dde9 100644
--- a/prelude/src/Data/Show.ss
+++ b/prelude/src/Data/Show.ss
@@ -54,14 +54,14 @@
   (define (string-join xs separator)
     (let ([len (rt:array-length xs)])
       (cond
-        [(= len 0) (string->pstring "")]
-        [(= len 1) (rt:array-ref xs 0)]
+        [(fx=? len 0) (string->pstring "")]
+        [(fx=? len 1) (rt:array-ref xs 0)]
         (else
           (let recur ([i 1]
                       [buffer (rt:array-ref xs 0)])
-            (if (= len i)
+            (if (fx=? len i)
               buffer
-              (recur (+ i 1) (pstring-concat buffer separator (rt:array-ref xs i)))))))))
+              (recur (fx1+ i) (pstring-concat buffer separator (rt:array-ref xs i)))))))))
 
   (define showArrayImpl
     (lambda (f)
diff --git a/prelude/src/Data/Show/Generic.ss b/prelude/src/Data/Show/Generic.ss
index 24a2ce7c..80da51d9 100644
--- a/prelude/src/Data/Show/Generic.ss
+++ b/prelude/src/Data/Show/Generic.ss
@@ -2,7 +2,7 @@
 
 (library (Data.Show.Generic foreign)
   (export intercalate)
-  (import (only (rnrs base) define lambda if let cond else = +)
+  (import (chezscheme)
           (only (purs runtime pstring) pstring pstring-concat)
           (prefix (purs runtime) rt:))
 
@@ -11,14 +11,14 @@
       (lambda (xs)
         (let ([len (rt:array-length xs)])
           (cond
-            [(= len 0) (pstring)]
-            [(= len 1) (rt:array-ref xs 0)]
+            [(fx=? len 0) (pstring)]
+            [(fx=? len 1) (rt:array-ref xs 0)]
             (else
               (let recur ([i 1]
                           [buffer (rt:array-ref xs 0)])
-                (if (= len i)
+                (if (fx=? len i)
                   buffer
-                  (recur (+ i 1)
+                  (recur (fx1+ i)
                          (pstring-concat buffer separator (rt:array-ref xs i)))))))))))
 
 )
diff --git a/st/src/Control/Monad/ST/Internal.ss b/st/src/Control/Monad/ST/Internal.ss
index d6636e8d..072044e7 100644
--- a/st/src/Control/Monad/ST/Internal.ss
+++ b/st/src/Control/Monad/ST/Internal.ss
@@ -41,7 +41,7 @@
       (lambda (hi)
         (lambda (f)
           (lambda ()
-            (do ([i lo (+ i 1)]) ((= i hi) 'unit)
+            (do ([i lo (fx1+ i)]) ((fx=? i hi) 'unit)
               ((f i))))))))
 
   (define foreach