proposition: Fact qpoly_scaleDl p : {morph qpoly_scale^~ p : a b / a + b}%R.
proof: Proof. by move=> a b; apply/val_eqP; rewrite /= scalerDl. 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)