proposition: Lemma pihomog_sym nv (p : {mpoly R[nv]}) : p \is symmetric -> 'pi_d p \is symmetric.
proof: Proof. by move=> /issymP Hp; apply/issymP => s; rewrite msym_pihomog Hp. 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