2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/66092A subset X of the Cantor space, 2^ω, is a lambda-prime-set iff for every countable subset Y of the Cantor space Y is relatively G-delta in X union Y. In this paper we prove two forcing results about lambda-prime-sets. First we show that it is consistent that every lambda-prime-set is a gamma-set. Secondly we show that is independent whether or not every dagger-lambda-set is a lambda-prime-set.12 pages LaTeX2eLogic03E17;03E35text