proposition: Lemma nderivn_map p n : p^f^`N(n) = (p^`N(n))^f.
proof: Proof. by apply/polyP => i; rewrite !(coef_map, coef_nderivn) //= rmorphMn. Qed.
imports: HB(structures) mathcomp(ssreflect ssrbool ssrfun eqtype ssrnat seq choice) mathcomp(fintype bigop finset tuple) mathcomp(div ssralg countalg binomial)