2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/144225We give a criterion for the section ring of an ample line bundle to be Koszul in terms of multigraded regularity. We discuss an application to polytopal semigroup rings.8 pagesAlgebraic GeometryCommutative AlgebraCombinatorics14C20; 13F20; 52B20; 16S37text