proposition: Lemma mem_msupp_mesym k m : m \in msupp 's_k = mechar k m.
proof: Proof. rewrite mcoeff_msupp mcoeff_mesym. by case: (mechar _ _); rewrite ?eqxx // oner_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