proposition: Lemma coef0 i : (0 : {poly R})`_i = 0.
proof: Proof. by rewrite coefC if_same. Qed.
imports: HB(structures) mathcomp(ssreflect ssrbool ssrfun eqtype ssrnat seq choice) mathcomp(fintype bigop finset tuple) mathcomp(div ssralg countalg binomial)