proposition: Lemma CatSnn n: Cat n.+1 n = catalan n.+1.
proof: Proof. by rewrite - Catnn Cat_rec // CatnSn. Qed.
imports: mathcomp(ssreflect ssrfun ssrbool eqtype) mathcomp(ssrnat seq path div) mathcomp(fintype tuple finfun bigop finset binomial)