pe (TyC s d) = "(mkFunTy (" ++ ppType s ++ ") (" ++ ppType d ++ "))"

pp
ppType (TyC s d) = "(mkFunTy (" ++ ppType s ++ ") (" ++ ppType d ++ "))"
ppType (TyC s d) = "(mkFunTy (" ++ ppType s ++ ") (" ++ ppType d ++ "))"