Haskell - How to write (.) f f = (\x -> f (f x))
问题 I need to write on a module to be run on GHCi, with a function composition to the same function. This (The classic fog(x) = f(g(x)) ) runs: (.) f g = (\x -> f (g x)). The problem appears when I try to write it like this (.) f f = (\x -> f (f x)). (fof(x) = f(f(x))) GHCi says: "Conflicting definitions for `f' Bound at: Lab1.hs:27:9 Lab1.hs:27:12" Line 27:9 appear on the first time f and line 27:12 appear f again. Why doesn't Haskell understand (.) f f = (\x -> f (f x)) ? 回答1: In Haskell,