2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/216250We show that A-hypergeometric systems and Horn hypergeometric systems are Weyl closed for very generic parameters.Changes in Section 2: Proposition 2.5 from version 1 was incorrectly proven; this has now been removed, and the proof of Theorem 2.7 no longer relies on that factAlgebraic GeometryCommutative AlgebraCombinatorics33C70, 32C38 (Primary); 14M25, 13N10 (Secondary)text