proposition: Lemma mderivmE m p : p^`M[m] = \sum_(m' <- msupp p) (p@_m' * (\prod_(i < n) (m' i)^_(m i))%:R *: 'X_[m'-m]).
proof: Proof. rewrite {1}[p]mpolyE raddf_sum /=; apply/eq_bigr=> m' _. by rewrite mderivmZ -scalerA -mderivmX. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq path) mathcomp(choice fintype tuple finfun bigop finset binomial) mathcomp(order fingroup perm ssralg zmodp poly ssrint) mathcomp(matrix vector) mathcomp(bigenough) ssrcomplements freeg