proposition: Lemma mmapZ c p : (c *: p)^[f,h] = (f c) * p^[f,h].
proof: Proof. pose_big_enough i. rewrite !(mmapE i) // mulr_sumr; apply/eq_bigr. by move=> j _; rewrite mcoeffZ mulrA -rmorphM. by close. 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