fact: Definition co_hpXY (la mu : 'P_d) : polXY -> algC := locked (co_hp la \o map_mpoly (co_hp mu)).
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