proposition: Lemma hornerMXaddC p c x : (p * 'X + c%:P).[x] = p.[x] * x + c.
proof: Proof. by rewrite -cons_poly_def horner_cons. Qed.
imports: HB(structures) mathcomp(ssreflect ssrbool ssrfun eqtype ssrnat seq choice) mathcomp(fintype bigop finset tuple) mathcomp(div ssralg countalg binomial)