2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/137271The problem is posed to find out for arbitrary nonvoid sets $X$ which are all the mappings $T : X \longrightarrow X$ that can be defined and each separately identified through means of categories alone. As argued, this problem may have a certain foundational relevance.General Mathematicstext