Update the parser

And merged it with the edited version we had. It seems that this extra
line is the only thing that changed.

src/GCLParser/Parser.y

@@ -71,6 +71,7 @@ import Debug.Trace
 
 %left implication
 %left or and 
+%left neg
 
 %nonassoc alias equal
 %nonassoc lessthan lessthanequal greaterthan greaterthanequal