proposition: Lemma nderivnC c n : (c%:P)^`N(n) = if n == 0 then c%:P else 0.
proof: Proof. apply/polyP=> i; rewrite coef_nderivn. by case: n => [|n]; rewrite ?bin0 // coef0 coefC mul0rn. Qed.
imports: HB(structures) mathcomp(ssreflect ssrbool ssrfun eqtype ssrnat seq choice) mathcomp(fintype bigop finset tuple) mathcomp(div ssralg countalg binomial)