2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/66693We construct a compact nonpositively curved squared 2-complex whose universal cover contains a flat plane that is not the limit of periodic flat planes.Published by Algebraic and Geometric Topology at http://www.maths.warwick.ac.uk/agt/AGTVol3/agt-3-6.abs.htmlGroup TheoryGeometric Topology20F67, 20F06text