+typeFun :: String [String] -> Env Type
+typeFun f es = gets (\(st, r)->'Map'.get f st) >>= \mt-> case mt of
+ Nothing = freshIdent >>= \frsh-> buildFunctionType frsh es
+ >>= \ft-> putIdent f ft >>| (pure $ IdType frsh)
+ Just t = unifyApp t es
+
+
+