fact: Definition Ufacts U a:= [/\ (forall x, (U x /\ ordinalU U x) <-> (ordinalp x /\ x <o a)), (forall x y, U x -> U y -> (x \Eq y <-> equipotentU U x y)), (forall x, cardinalU U x <-> (cardinalp x /\ x <c a)), (forall x y, cardinalU U x -> cardinalU U y -> powerU U x y = (x ^c y)) & (forall x, inaccessibleU U x <-> (inaccessible x /\ x <c a)) ].
imports: mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat)