proposition: Fact polXY_scaleAl (c : R) (p q : polXY) : c *: (p * q : polXY) = (c *: p) * q.
proof: Proof. by rewrite !scale_polXYE /polXY_scale /= -!mul_mpolyC mulrA. Qed.
imports: HB(structures) mathcomp(all_ssreflect) mathcomp(ssrint rat ssralg ssrnum algC matrix vector) mathcomp(mpoly) tools partition ordtype antisym Schur_mpoly Schur_altdef sympoly homogsym permcent