proposition: Lemma poly_XmY0 : poly_XmY 0 = 0.
proof: Proof. by rewrite /poly_XmY rmorph0 comp_poly0. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype choice ssrnat seq) mathcomp(fintype tuple finfun bigop fingroup perm div) mathcomp(ssralg zmodp matrix mxalgebra) mathcomp(poly polydiv mxpoly binomial)