proposition: Lemma mpolyE p : p = \sum_(m <- msupp p) (p@_m *: 'X_[m]).
proof: Proof. apply/mpolyP=> m; rewrite {1}[p]freeg_mpoly /= mcoeff_MPoly. rewrite !raddf_sum /=; apply/eq_bigr=> i _. by rewrite -mul_mpolyC mcoeffCM mcoeffX coeffU. 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