Function composition is a single, special case of a function accepting functional arguments. You could define the compose operator as below: compose : (a -

Function composition is a single, special case of a function accepting functional arguments. You could define the compose operator as below: compose : (a -> b) -> (b -> c) -> (a -> c) a `compose` b = \x -> b(a(x)) However, there is a whole spectrum of additionally possible functions which can be built to accept functions as arguments. Here's a couple of example: partial3 : (Integer -> Integer -> Integer) -> (Integer -> Integer) partial3 f = f 3 map : [a] -> (a -> b) -> [b] map [] f = [] map (x:xs) f = (f x):(map xs f) The first one takes a function and applies an argument, 3; the next one takes a list and a function and maps the list using the provided function. The idea of functions as arguments is a very powerful one, and from my understanding one with which people sometimes struggle.