---------------
---- Tests ----
---------------

-- Function properties

prop_product :: (Num a, Eq a) => [a] -> Bool
prop_product xs = (product' xs) == (product xs)
prop_product :: (Num a, Eq a) => [a] -> Bool
prop_product xs = (product' xs) == (product xs)
prop_product xs = (product' xs) == (product xs)