-- rewrite uses of fake primops
mungeVarName (Var (Just mn', v))
| mn' == mn && v `elem` (fst (unzip newPrimVars)) =
Var (Just primMname, v)
-- rewrite uses of fake primops
mungeVarName (Var (Just mn', v))
| mn' == mn && v `elem` (fst (unzip newPrimVars)) =
Var (Just primMname, v)