proposition: Lemma mpoly_mulC p q : p * q = q * p.
proof: Proof. apply/mpolyP=> /= m; rewrite mcoeffM mcoeffMr. by apply: eq_bigr=> /= i _; rewrite mulrC. 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