Formatting

Clean up Main.hs formatting; clarify language in parsing branch

src/Parser.hs

@@ -49,7 +49,7 @@ parseApplication = do
   func <- parseAtomicBase
   args <- many parseAtomic
   case func of
-    TLeaf | not (null args) && all isTreeTerm args -> fail "Not an application, defer to Tree Calculus"
+    TLeaf | not (null args) && all isTreeTerm args -> fail "Defer to Tree Calculus"
     _ -> return (SApp func args)
 
 isTreeTerm :: SaplingAST -> Bool