2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/76393Robbins conjectured, and Zeilberger recently proved, that there are 1!4!7!...(3n-2)!/n!/(n+1)!/.../(2n-1)! alternating sign matrices of order n. We give a new proof of this result using an analysis of the six-vertex state model (also called square ice) based on the Yang-Baxter equation.10 pagesCombinatoricstext