proposition: Lemma coeff_prodgen_cast l k nu (eqlamu : l = k) (eqsum : sumn l = sumn k) : 'co[cast_intpartn eqsum nu] = 'co[nu].
proof: Proof. by subst k; congr coeff_prodgen_seq; apply val_inj; rewrite cast_intpartnE. 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