2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/73703We develop the semifilter approach to the classical Menger and Hurewicz covering properties and show that the small cardinal g is a lower bound of the additivity number of the family of Menger subspaces of the Baire space, and under u< g every subset X of the real line with the property Split(Lambda,Lambda) is Hurewicz.LaTeX 2e, 15 pages, submitted to Comment. Math. Univ. CarolinaeGeneral TopologyCombinatorics54D20 (Primary); 03E17, 03E35 (Secondary)text