proposition: Lemma deriv_mulC c p : (c%:P * p)^`() = c%:P * p^`().
proof: Proof. by rewrite !mul_polyC derivZ. Qed.
imports: HB(structures) mathcomp(ssreflect ssrbool ssrfun eqtype ssrnat seq choice) mathcomp(fintype bigop finset tuple) mathcomp(div ssralg countalg binomial)