proposition: Lemma comp_poly2_eq0 p q : size q = 2 -> (p \Po q == 0) = (p == 0).
proof: Proof. by rewrite -!size_poly_eq0 => /size_comp_poly2->. Qed.
imports: HB(structures) mathcomp(ssreflect ssrbool ssrfun eqtype ssrnat seq choice) mathcomp(fintype bigop finset tuple) mathcomp(div ssralg countalg binomial)