proposition: Lemma urank_alt2 a x: ordinalp a -> inc x (universe a) -> inc x (universe (osucc (urank a x))).
proof: Proof. move => oa xa; rewrite - (urank_alt1 oa xa). by move: (urankA_pr oa xa) => [h1 []]. Qed.
imports: mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat)