testsuite: Assert that testsuite ways are known
[ghc.git] / testsuite / tests / typecheck / should_compile / T13651a.hs
1 {-# LANGUAGE TypeFamilies, TypeFamilyDependencies #-}
2 module T13651 where
3
4 type family F r s = f | f -> r s
5
6 type instance F (Bar h (Foo r)) (Bar h (Foo s)) = Bar h (Bar r s)
7
8 data Bar s b
9 data Foo a
10
11 foo :: (F cr cu ~ Bar h (Bar r u),
12 F cu cs ~ Bar (Foo h) (Bar u s))
13 => Bar h (Bar r u) -> Bar (Foo h) (Bar u s) -> cu -> Foo (cr -> cs)
14 -- A variant of T13651 which fixes 'cu'
15 -- as well as the other type args
16 foo = undefined