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{-# LANGUAGE GADTs #-}
{-# OPTIONS_GHC -Wredundant-constraints #-}
module T9939 where
f1 :: (Eq a, Ord a) => a -> a -> Bool
-- Eq a redundant
f1 x y = (x == y) && (x > y)
f2 :: (Eq a, Ord a) => a -> a -> Bool
-- Ord a redundant, but Eq a is reported
f2 x y = (x == y)
f3 :: (Eq a, a ~ b, Eq b) => a -> b -> Bool
-- Eq b redundant
f3 x y = x==y
data Equal a b where
EQUAL :: Equal a a
f4 :: (Eq a, Eq b) => a -> b -> Equal a b -> Bool
-- Eq b redundant
f4 x y EQUAL = y==y
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