[trobertson]

I don't mean to nitpick, but the three parameter form is exactly what you use in day-to-day Haskell programming. You simply let c be the infix (->), and you get (y -> z) -> (x -> y) -> (x -> z). We just tend to think of it as a two parameter form because a lot of the time, you can think of (->) as syntax, as opposed to the type that it is.

[lelf]

Yup. This is straight cut from Control.Category module:

  instance Category (->) where
      id = Prelude.id
      (.) = (Prelude..)