2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/80313A generalised ladder operator is used to construct the conserved operators for any model derived from the Yang-Baxter equation. As an example, the low order conserved operators for the XYh model are calculated explicitly.6 pages, latex, no figuresExactly Solvable and Integrable Systemstext