diff --git a/partial_eval.csc b/partial_eval.csc
new file mode 100644
index 0000000..862605e
--- /dev/null
+++ b/partial_eval.csc
@@ -0,0 +1,65 @@
+(import (chicken process-context))
+(import (chicken port))
+(import (r5rs))
+(define-syntax rec-lambda
+    (er-macro-transformer
+         (lambda (x r c)
+                (let (
+                         (name (car (cdr x)))
+                         (params (car (cdr (cdr x))))
+                         (body (car (cdr (cdr (cdr x)))))
+                     )
+                     `(rec ,name (lambda ,params ,body))))))
+(let* (
+       (array list)
+       (concat append)
+       (len length)
+       (idx list-ref)
+
+       (= equal?)
+       (drop (rec-lambda recurse (x i) (if (= 0 i) x (recurse (cdr x) (- i 1)))))
+       (take (rec-lambda recurse (x i) (if (= 0 i) '() (cons (car x) (recurse (cdr x) (- i 1))))))
+       (slice (lambda (x s e) (let* ( (l (len x))
+                                      (s (if (< s 0) (+ s l 1) s))
+                                      (e (if (< e 0) (+ e l 1) e))
+                                      (t (- e s)) )
+                               (take (drop x s) t))))
+      )
+
+(let* (
+
+    (val?                   (lambda (x) (= 'val (idx x 0))))
+    (.val                   (lambda (x) (idx x 1)))
+    (marked_array?          (lambda (x) (= 'marked_array (idx x 0))))
+    (.marked_array_is_val   (lambda (x) (idx x 1)))
+    (.marked_array_values   (lambda (x) (idx x 2)))
+    (marked_symbol?         (lambda (x) (= 'marked_symbol (idx x 0))))
+    (.marked_symbol_is_val  (lambda (x) (idx x 1)))
+    (.marked_symbol_value   (lambda (x) (idx x 2)))
+    (comb?                  (lambda (x) (= 'comb (idx x 0))))
+    (.comb                  (lambda (x) (slice x 1 -1)))
+    (prim_comb?             (lambda (x) (= 'prim_comb (idx x 0))))
+    (.prim_comb             (lambda (x) (idx x 1)))
+    (marked_env?            (lambda (x) (= 'env (idx x 0))))
+    (marked_env_real?       (lambda (x) (idx x 1)))
+    (.marked_env_idx        (lambda (x) (idx x 2)))
+    (.env_marked            (lambda (x) (idx x 3)))
+
+    (test-all (lambda () (begin
+        (print (val? '(val)))
+        (print "take 3" (take '(1 2 3 4 5 6 7 8 9 10) 3))
+        (print "drop 3" (drop '(1 2 3 4 5 6 7 8 9 10) 3))
+        (print (slice '(1 2 3) 1 2))
+        (print (slice '(1 2 3) 1 -1))
+        (print (slice '(1 2 3) -1 -1))
+        (print (slice '(1 2 3) -2 -1))
+
+        (print (array 1 2 3))
+        (print (command-line-arguments))
+
+        (print (call-with-input-string "'(1 2)" (lambda (p) (read p))))
+        (print (read (open-input-string "'(3 4)")))
+    )))
+
+) (test-all))
+)
diff --git a/shell.nix b/shell.nix
index 9be631e..4c01652 100644
--- a/shell.nix
+++ b/shell.nix
@@ -8,5 +8,7 @@ mkShell {
     nodejs
     valgrind
     kcachegrind
+    chicken
+    chez
   ];
 }