prop_deleteAll :: Eq a => a -> [a] -> Bool
prop_deleteAll n xs = (deleteAll n xs) == (filter (\x -> x /= n) xs)
prop_deleteAll :: Eq a => a -> [a] -> Bool
prop_deleteAll n xs = (deleteAll n xs) == (filter (\x -> x /= n) xs)
prop_deleteAll n xs = (deleteAll n xs) == (filter (\x -> x /= n) xs)