mkPiTypes :: [Var] -> Type -> Type
-- ^ 'mkPiType' for multiple type or value arguments

mkPiType v ty
   | isId v    = mkFunTy (varType v) ty
   | otherwise = mkForAllTy v ty
mkPiTypes :: [Var] -> Type -> Type
mkPiType v ty
   | isId v    = mkFunTy (varType v) ty
   | otherwise = mkForAllTy v ty
mkPiType v ty
   | isId v    = mkFunTy (varType v) ty
   | otherwise = mkForAllTy v ty