proposition: Lemma comm_poly1 x : comm_poly 1 x.
proof: Proof. by rewrite /comm_poly !hornerC !simp. Qed.
imports: HB(structures) mathcomp(ssreflect ssrbool ssrfun eqtype ssrnat seq choice) mathcomp(fintype bigop finset tuple) mathcomp(div ssralg countalg binomial)