proposition: Lemma mdeg_monX mon : mdeg (monX mon) = mdeg mon.
proof: Proof. rewrite /mdeg /monX !big_tuple big_mxvec_index /=; apply eq_bigr => i _. rewrite tnth_mktuple; apply eq_bigr => j _. by rewrite mnm_tnth. Qed.
imports: HB(structures) mathcomp(all_ssreflect) mathcomp(ssrint rat ssralg ssrnum algC matrix vector) mathcomp(mpoly) tools partition ordtype antisym Schur_mpoly Schur_altdef sympoly homogsym permcent