fact: Definition symh_pol_bound b d : {mpoly R[n]} := \sum_(m : 'X_{1..n < b} | mdeg m == d) 'X_[m].
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