prop_sum xs n = n > 0 ==> runner1 (enumSpecial xs n Iter.sum) == P.sum xs
  where types = (xs :: [Int])
prop_sum xs n = n > 0 ==> runner1 (enumSpecial xs n Iter.sum) == P.sum xs
  where types = (xs :: [Int])
prop_sum xs n = n > 0 ==> runner1 (enumSpecial xs n Iter.sum) == P.sum xs
  where types = (xs :: [Int])