proposition: Lemma poly_XaY_eq0 p : (poly_XaY p == 0) = (p == 0).
proof: Proof. by rewrite -!size_poly_eq0 size_poly_XaY. 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)