2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/59003Let $(X,Δ)$ be a 4-dimensional log variety which is proper over the field of complex numbers and with only divisorial log terminal singularities. The log canonical divisor $K_X+Δ$ is semi-ample, if it is nef (numerically effective) and the Iitaka dimension $κ(X,K_X+Δ)$ is strictly positive. For the proof, we use Fujino's abundance theorem for semi log canonical threefolds.11 pages, AMSTex v2.1, the published versionAlgebraic Geometry14E30 (Primary) 14J35, 14C20 (Secondary)text