proposition: Lemma ends_with_a_rcons a l: ends_with_a (rcons l a) a.
proof: Proof. by rewrite /ends_with_a /=; case: l => // b l; rewrite belast_rcons. Qed.
imports: mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat) mathcomp(seq choice fintype order bigop ssralg) mathcomp(div ssrnum ssrint rat prime path binomial) mathcomp(tuple finset) gaia(fibm)