proposition: Lemma homsymmE (f : {homsym R[n, d]}) : f = \sum_(l : 'P_d) f@_(mpart l) *: homsymm l.
proof: Proof. by apply val_inj; rewrite /= {1}(homog_symmE (homsym_is_dhomog f)) !linear_sum. Qed.
imports: HB(structures) mathcomp(all_ssreflect) mathcomp(ssralg matrix vector ssrnum algC archimedean) mathcomp(fingroup perm) mathcomp(ssrcomplements freeg mpoly) tools sorted ordtype permuted partition permcent antisym Schur_mpoly Schur_altdef sympoly