I pasted the wrong version into the mail. This is the final one: module InfixFunction where infixl 0 $- infixr 0 $+ -- for left-associative functions ($<) :: a -> (a -> b) -> b ($<) x f = f x -- for right-associative functions ($>) :: a -> (a -> b) -> b ($>) x f = f x example1 :: Int example1 = -- 3 `\x y -> x + y` 4 3 $< (\y x -> x + y) 4 example2 :: Int example2 = -- 1 `\x y -> x + y` 2 `\x y -> x` 3 1 $> (\y x -> x + y) 2 $> (\y x -> x + y) 3 Rijk-Jan van Haaften