2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/78471We determine the Seiberg-Witten-Floer homology groups of the three-manifold which is the product of a surface of genus $g \geq 1$ times the circle, together with its ring structure, for spin-c structures which are non-trivial on the three-manifold. We give applications to computing Seiberg-Witten invariants of four-manifolds which are connected sums along surfaces and also we reprove the higher type adjunction inequalities previously obtained by Oszváth and Szabó.26 pages, no figures, Latex2e, to appear in Math. NachDifferential Geometry57R57; 57N13text