proposition: Lemma qpoly_mulC : commutative (@qpoly_mul A h).
proof: Proof. by move=> p q; apply: val_inj; rewrite /= mulrC. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq choice fintype tuple) mathcomp(bigop binomial finset finfun ssralg countalg finalg poly polydiv) mathcomp(perm fingroup matrix mxalgebra mxpoly vector countalg)