2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/216754We reformulate the nested coordinate Bethe ansatz in terms of coproducts of Yangian symmetry generators. This allows us to derive the nested Bethe equations for the bound state string S-matrices. We find that they coincide with the Bethe equations obtained from a fusion procedure. The bound state number dependence in the Bethe equations appears through the parameters x^{\pm} and the dressing phase only.typos correctedHigh Energy Physics - Theorytext