pub type Aq<A, B> = And<Eq<A, B>, And<Qu<Not<A>>, Qu<Not<B>>>>;
Aquality definition (a ~¬~ b) == ((a == b) ⋀ ~¬a ⋀ ~¬b).
(a ~¬~ b) == ((a == b) ⋀ ~¬a ⋀ ~¬b)