diff --git a/src/mumble.c b/src/mumble.c
index 6fb8eeb..102d010 100644
--- a/src/mumble.c
+++ b/src/mumble.c
@@ -179,19 +179,21 @@ int main(int argc, char** argv)
 
     /* Create Some Parsers */
     mpc_parser_t* Number = mpc_new("number");
-    mpc_parser_t* Operator = mpc_new("operator");
+    mpc_parser_t* Symbol = mpc_new("symbol");
+    mpc_parser_t* Sexpr = mpc_new("sexpr");
     mpc_parser_t* Expr = mpc_new("expr");
     mpc_parser_t* Mumble = mpc_new("mumble");
 
     /* Define them with the following Language */
     mpca_lang(MPCA_LANG_DEFAULT,
-        "                                               \
-    number   : /-?[0-9]+/ ;                             \
-    operator : '+' | '-' | '*' | '/' ;                  \
-    expr     : <number> | '(' <operator> <expr>+ ')' ;  \
-    mumble    : /^/ <operator> <expr>+ | <expr>/$/ ;             \
+        "                                       \
+    number   : /-?[0-9]+/ ;                     \
+    symbol : '+' | '-' | '*' | '/' ;            \
+		sexpr : '(' <expr>* ')' ;                   \
+    expr     : <number> | <symbol> | <sexpr> ;  \
+    mumble    : /^/ <expr>* /$/ ;               \
   ",
-        Number, Operator, Expr, Mumble);
+        Number, Symbol, Sexpr, Expr, Mumble);
 		
 
 		// Initialize a repl
@@ -230,7 +232,7 @@ int main(int argc, char** argv)
     }
 
     /* Undefine and Delete our Parsers */
-    mpc_cleanup(4, Number, Operator, Expr, Mumble);
+    mpc_cleanup(4, Number, Symbol, Sexpr, Expr, Mumble);
 
     return 0;
 }