2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/140791In a locally finite tiling of n-dim Euclidean space by convex polytopes, each point of the space is either a vertex of at least two tiles, or no vertex at all.8 pages, 2 figuresMetric Geometry52C22The Lonely Vertex Problemtext