2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/139045Let X and Y be separable metrizable spaces, and f:X-->Y be a function. We want to recover f from its values on a small set via a simple algorithm. We show that this is possible if f is Baire class one, and in fact we get a characterization. This leads us to the study of sets of Baire class one functions and to a characterization of the separability of the dual space of an arbitrary Banach space.LogicFunctional AnalysisGeneral Topology26A21, 54H05, 03E15, 46A20text