lol.hs

chk :: Eq b => (a -> b) -> a -> b -> Bool
-- All arguments are present on the left
-- chk fn a b = b == fn a

-- get rid of 'b' param on the left by partially applying (==) operator
-- chk fn a = (== fn a)

-- get rid of 'a' param on the left by composing (==) after fn
-- chk fn = (==) . fn

-- get rid of fn on the left by partially applying the (.) operator
chk = ((==) .)