ref: fdb26350514c86ea3079aa9cb4a8e43090f4861d 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