fact: Definition symm sh : {sympoly R[n]} := if size sh <= n then SymPoly (symm_sym (mpart sh)) else 0 : {sympoly R[n]}.
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