proposition: Lemma mwiden_is_multiplicative : multiplicative mwiden.
proof: Proof. apply/commr_mmap_is_multiplicative=> [i p|p m m']; first exact/commr_mpolyX. rewrite /= /mmap1; elim/big_rec: _ => /= [|i q _]; first exact/commr1. exact/commrM/commrX/commr_mpolyX. 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