diff --git a/examples/sandbox.txt b/examples/sandbox.txt
index db1bfb4..0b1097e 100644
--- a/examples/sandbox.txt
+++ b/examples/sandbox.txt
@@ -12,13 +12,13 @@
 # # (fib 3)
 # # (fib 4)
 # # (fib 5)
-# 
-# (define! let!
-#     (lambda! (a b c)
-#         ((lambda (list! a) c) b)))
-# 
-# (let! x 3 (+ x 2))
-# 
+
+(define! let1!
+    (lambda! (a b c)
+        ((lambda (list! a) c) b)))
+
+(let1! x 3 (+ x 2))
+
 # (define! let2!
 #     (lambda! (a b c d e)
 #         ((lambda (list! a b) e) c d)))
@@ -31,18 +31,39 @@
 # 
 # (let3! (x y z) (1 2 3) (+ x y z 2))
 
-(define Y
-   (lambda (f)
-        (f (lambda (x) ((Y f) x)))))
+# (define Y
+#    (lambda (f)
+#         (f (lambda (x) ((Y f) x)))))
+# 
+# (define almost-factorial
+#     (lambda (f)
+#         (lambda (n)
+#             (if/else (= n 0)
+#                 1
+#                 (* n (f (- n 1)))))))
+# 
+# (define factorial (Y almost-factorial))
+# 
+# (factorial 1)
+# (factorial 2)
+# (factorial 3)
+# (factorial 4)
 
-(define almost-factorial
-    (lambda (f)
-        (lambda (n)
+# (let1! x 3 (+ x 2))
+
+# (define almost
+#     (lambda (f n)
+#         (if/else (= n 0)
+#             1
+#             (* n (f f (- n 1))))))
+
+(define factorial
+    (let1! almost
+        (lambda (f n)
             (if/else (= n 0)
                 1
-                (* n (f (- n 1)))))))
-
-(define factorial (Y almost-factorial))
+                (* n (f f (- n 1)))))
+        (lambda (x) (almost almost x))))
 
 (factorial 1)
 (factorial 2)
@@ -52,6 +73,3 @@
 
 
 
-
-
-