prop_equal :: Int -> Bool
prop_equal n = all p $ pairs cats
 where
  cats = [cat0, cat1, cat2, cat3, cat4, cat5, cat6]
  p (xs, ys) = xs !! n' == ys !! n'
  n' = n `mod` 1000
prop_equal :: Int -> Bool
prop_equal n = all p $ pairs cats
 where
  cats = [cat0, cat1, cat2, cat3, cat4, cat5, cat6]
  p (xs, ys) = xs !! n' == ys !! n'
  n' = n `mod` 1000
prop_equal n = all p $ pairs cats
 where
  cats = [cat0, cat1, cat2, cat3, cat4, cat5, cat6]
  p (xs, ys) = xs !! n' == ys !! n'
  n' = n `mod` 1000