proposition: Lemma mlast_supp p : p != 0 -> mlast p \in msupp p.
proof: Proof. rewrite -msupp_eq0 /mlast; move: (msupp p) => s nz_s. rewrite -(perm_mem (permEl (perm_sort <=%O%O _))). by rewrite -nth0 mem_nth // size_sort lt0n size_eq0. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq path) mathcomp(choice fintype tuple finfun bigop finset binomial) mathcomp(order fingroup perm ssralg zmodp poly ssrint) mathcomp(matrix vector) mathcomp(bigenough) ssrcomplements freeg