2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/59495This paper is concerned with some well-known Ljusternik-Schnirelmann categories. We desire to find some links and relations among them. This has been done by using the concepts of precategoty, T-collection and closure of a category.9 pagesGeneral Topology55M30text