+subeverywhere trans (Var x) = return $ Var x
+subeverywhere trans (Lit x) = return $ Lit x
+subeverywhere trans (Type x) = return $ Type x
+
+subeverywhere trans (Cast expr ty) = do
+ expr' <- trans expr
+ return $ Cast expr' ty
+
+subeverywhere trans expr = error $ "NormalizeTools.subeverywhere Unsupported expression: " ++ show expr