    {-# LANGUAGE TypeFamilies #-}

    module Types where

    data Quux = Bar | Baz

    newtype Foo = Foo ()

    type FooQuux = (Foo, Quux)
    type QuuxFoo = (Quux, Foo)

    data family Norf a b

    data instance Norf Foo Quux = NFQ Foo Quux
    data instance Norf Quux Foo = NQF Quux Foo

    type family Norf' a b

    type instance Norf' Foo Quux = (Foo, Quux)
    type instance Norf' Quux Foo = (Quux, Foo)

    norf1 :: Norf Foo Quux -> Int
    norf1 (NFQ (Foo ()) Bar) = 0
    norf1 (NFQ (Foo ()) Baz) = 1

    norf2 :: Norf Quux Foo -> Int
    norf2 (NQF Bar (Foo ())) = 0
    norf2 (NQF Baz (Foo ())) = 1

    norf1' :: Norf' Foo Quux -> Int
    norf1' (Foo (), Bar) = 0
    norf1' (Foo (), Baz) = 1

    norf2' :: Norf' Quux Foo -> Int
    norf2' (Bar, Foo ()) = 0
    norf2' (Baz, Foo ()) = 1