2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/72122This is the second in a series of papers about torsion-free groups which act properly and cocompactly on a CAT(0) metric space with isolated flats and relatively thin triangles. Our approach is to adapt the methods of Sela and others for word-hyperbolic groups to this context of non-positive curvature. The main result in this paper is that (under certain technical hypotheses) such a group as above is Hopfian. This (mostly) answers a question of Sela.38 pagesGroup Theory20F65, 20F67, 20E08, 57M07text