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module T5776 where
-- The point about this test is that we should get a rule like this:
-- "foo" [ALWAYS]
-- forall (@ a)
-- ($dEq :: Eq a)
-- ($dEq1 :: Eq a)
-- (x :: a)
-- (y :: a)
-- (z :: a).
-- T5776.f (g @ a $dEq1 x y)
-- (g @ a $dEq y z)
-- = GHC.Types.True
--
-- Note the *two* forall'd dEq parameters. This is important.
-- See Note [Simplifying RULE lhs constraints] in GHC.Tc.Solver
{-# RULES "foo" forall x y z.
f (g x y) (g y z) = True
#-}
g :: Eq a => a -> a -> Bool
{-# NOINLINE g #-}
g = (==)
f :: Bool -> Bool -> Bool
{-# NOINLINE f #-}
f a b = False
blah :: Int -> Int -> Bool
blah x y = f (g x y) (g x y)
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