proposition: Lemma last_iota a b c: last c (iota a b.+1) = a + b.
proof: Proof. by rewrite iota_Sr last_rcons. Qed.
imports: mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat) mathcomp(seq path fintype div bigop binomial) mathcomp(prime finset ssralg ssrnum ssrint)