2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/106237We present a general theory of absolutely continuous paths with values in metric spaces using the notion of metric derivatives. Among other results, we prove analogues of the Banach-Zarecki and Vallee Poussin theorems.9 pagesClassical Analysis and ODEsMetric Geometry26A46; 26E20text