proposition: Lemma polyCM : {morph polyC : a b / a * b}.
proof: Proof. by move=> a b; apply/polyP=> [[|i]]; rewrite coefCM !coefC ?simp. Qed.
imports: HB(structures) mathcomp(ssreflect ssrbool ssrfun eqtype ssrnat seq choice) mathcomp(fintype bigop finset tuple) mathcomp(div ssralg countalg binomial)