2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/221609We show that for a C^infty stable map of an oriented 4-manifold into a 3-manifold, the algebraic number of singular fibers of a specific type coincides with the signature of the source 4-manifold.This is the version published by Geometry & Topology on 7 April 2006Geometric Topology57R45, 57N13, 58K15, 58K30text