prop_maximum' :: [Integer] -> Property
prop_maximum' integerList

 =       integerList /= []
    ==>  maximum' integerList == Data.List.maximum integerList
prop_maximum' :: [Integer] -> Property
prop_maximum' integerList

 =       integerList /= []
    ==>  maximum' integerList == Data.List.maximum integerList
prop_maximum' integerList

 =       integerList /= []
    ==>  maximum' integerList == Data.List.maximum integerList