proposition: Lemma symm_unique0 d c : \sum_(l : 'P_d) (c l) *: 'm[l] = 0 -> forall l : 'P_d, size l <= n -> c l = 0.
proof: Proof. by move=> /esym/symm_unique => H l /H ->; rewrite mcoeff0. Qed.
imports: HB(structures) mathcomp(all_ssreflect) mathcomp(ssralg ssrint fingroup perm) mathcomp(ssrcomplements freeg mpoly) sorted tools ordtype permuted partition skewpart composition Yamanouchi std tableau stdtab skewtab permcent antisym Schur_mpoly therule Schur_altdef unitriginv