In addition to Paul Hudak's "The Haskell School of Expression", Appendix A "Built-in types are not special" I want to note that there is also hardly a need for integer literals. :-] module Digits where infixl 9 # (#) :: a -> (a -> b) -> b x # f = f x int :: Num a => a int = 0 d0, d1, d2, d3, d4, d5, d6, d7, d8, d9 :: (Enum a, Num a) => a -> a d0 n = n+n+n+n+n+n+n+n+n+n d1 = succ . d0 d2 = succ . d1 d3 = succ . d2 d4 = succ . d3 d5 = succ . d4 d6 = succ . d5 d7 = succ . d6 d8 = succ . d7 d9 = succ . d8 test :: (Enum a, Num a) => a test = int#d1#d4#d2#d8#d5#d7 * int#d2#d1