fact: Definition Ymon (ms : m.-tuple 'X_{1.. n}) := [multinom (tnth ms (vecmx_index i).1) (vecmx_index i).2 | i < m*n].
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