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module DfltProb2 where
{- NB: This program fails in GHC 7.4.1 but should be accepted with our new defaulting plan -}
f :: Int -> Bool
f x = const True (\y -> let w :: a -> a
w a = const a (y+1)
in w y)
{- The implication constraint we get here is that (y::beta):
[untch=beta] forall a. 0 => Num beta
and we can't really do any defaulting in this scope.
Instead with our new defaulting plan we
(i) try to approximate the whole constraint
(ii) /then/ we try to default (and succeed)
(iii) then try to resolve again
See Note [Top-level Defaulting Plan] in GHC.Tc.Solver -}
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