proposition: Fact evalXY_is_linear : linear evalXY.
proof: Proof. rewrite /evalXY => r p q. by rewrite mmapD mmapZ /= scale_polXYE /polXY_scale /= -!mul_mpolyC. 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