2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/63108In this paper it is shown that manifolds admitting minimal genus weakly reducible but irreducible Heegaard splittings contain an essential surface. This is an extension of a well known theorem of Casson-Gordon to manifolds with non-empty boundary. The situation for non-minimal genus Heegaard splittings is also investigated and it is shown that boundary stabilizations are stabilizations for manifolds which are boundary primitive.13 pages 3 figures. Will appear in Topology and its ApplicationsGeometric Topologytext