deque-blog/rapid_check_3_find_failing.hs

## rapid_check_3_find_failing.hs
findFailing :: [a] -> (a -> Result) -> Maybe (a, Result)
findFailing smaller runSub =
  let results = map runSub smaller
  in find (isFailure . snd) (zip smaller results)
	findFailing :: [a] -> (a -> Result) -> Maybe (a, Result)
	findFailing smaller runSub =
	let results = map runSub smaller
	in find (isFailure . snd) (zip smaller results)