prop_univIsIntersectionIdentity :: SetOf e s => s -> Bool
prop_univIsIntersectionIdentity s = (s `intersection` univ) `sameAs` s
prop_univIsIntersectionIdentity :: SetOf e s => s -> Bool
prop_univIsIntersectionIdentity s = (s `intersection` univ) `sameAs` s
prop_univIsIntersectionIdentity s = (s `intersection` univ) `sameAs` s