diff --git a/mumble b/mumble
index 76e9bb5..f36ebc6 100755
Binary files a/mumble and b/mumble differ
diff --git a/src/mumble.c b/src/mumble.c
index 017ec1c..4c086bf 100644
--- a/src/mumble.c
+++ b/src/mumble.c
@@ -377,7 +377,8 @@ int main(int argc, char** argv)
     /* Define them with the following Language */
     mpca_lang(MPCA_LANG_DEFAULT, "                           \
     number   : /-?[0-9]+\\.?([0-9]+)?/ ;                     \
-    symbol : '+' | '-' | '*' | '/' ;                         \
+    symbol : \"list\" \"head\" \"tail\" \"eval\"             \
+		       | '+' | '-' | '*' | '/' ;                         \
 		sexpr : '(' <expr>* ')' ;                                \
 		qexpr : '{' <expr>* '}' ;                                \
     expr     : <number> | <symbol> | <sexpr> | <qexpr>;      \