proposition: Lemma nderivn_def n p : p^`(n) = p^`N(n) *+ n`!.
proof: Proof. by apply/polyP=> i; rewrite coefMn coef_nderivn coef_derivn -mulrnA bin_ffact. Qed.
imports: HB(structures) mathcomp(ssreflect ssrbool ssrfun eqtype ssrnat seq choice) mathcomp(fintype bigop finset tuple) mathcomp(div ssralg countalg binomial)