How to correctly write left fold in Haskell

fold.hs

{-# LANGUAGE NoMonomorphismRestriction #-}

-- pull in the necessary modules
import Control.Cond (if')
import Control.Monad (ap)
import Control.Monad.Fix (fix)
import Data.Foldable (null)

-- fold over a list
fold :: (a -> b -> a) -> a -> [b] -> a
fold = x ((a (a . f (i . n)) .) . f f t . ((f . (a .)) .) . (`a` (f f h . ((.) .))) . (((.) . (.)) .))
  where a = ap; f = flip; h = head; i = if'; n = null; t = tail; x = fix

main = print $ fold (*) 1 [1..6] -- 720