ref: ac79f6fa5090e27752e3381f6538e061d12f07ff dir: /tests/Eq1.hs/
module Eq1 where class Eq1 f where eq1 :: (Eq a) => f a -> f a -> Bool instance Eq1 Maybe where eq1 = (==) main :: IO () main = do let x = Just (1::Int) print $ eq1 x x