Add "if" built-in
diff --git a/src/lisp/test.lisp b/src/lisp/test.lisp
index 68cc615..82e5955 100644
--- a/src/lisp/test.lisp
+++ b/src/lisp/test.lisp
@@ -3,4 +3,5 @@
 
 (defun main ()
   (print "64 / (2 + 2) =")
-  (print (/ 64 (two-plus-two))))
+  (print (/ 64 (two-plus-two)))
+  (print nil))