2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/60144We show that every smooth closed oriented four-manifold admits a decomposition into two co- dimension zero submanifolds with common boundary. Each of these submanifolds carries a structure of a symplectic manifold with pseudo-convex boundary. This imply, in particular, that every smooth closed simply-connected four-manifold is a Stein domain in the the complement of a certain contractible 2-complex.LaTeX2e, 9 pages, 5 figuresGeometric TopologySymplectic Geometry57M50; 57R17text