proposition: Lemma lead_coefZ a p : lead_coef (a *: p) = a * lead_coef p.
proof: Proof. by rewrite -mul_polyC lead_coefM lead_coefC. Qed.
imports: HB(structures) mathcomp(ssreflect ssrbool ssrfun eqtype ssrnat seq choice) mathcomp(fintype bigop finset tuple) mathcomp(div ssralg countalg binomial)