proposition: Lemma cnvar_syms (la : 'P_d) : cnvarsym 's[la] = 's[la].
proof: Proof. rewrite !syms_symh linear_sum; apply eq_bigr => mu _. by rewrite linearZ /= cnvar_prodsymh. 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