2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/68299The Waldhausen construction of Mayer-Vietoris splittings of chain complexes over an injective generalized free product of group rings is extended to a combinatorial construction of Seifert-van Kampen splittings of CW complexes with fundamental group an injective generalized free product.Published by Geometry and Topology Monographs at http://www.maths.warwick.ac.uk/gt/GTMon7/paper6.abs.htmlAlgebraic TopologyGeometric Topology57R67, 19J25text