2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/118843We present tableau calculi for some logics of nonmonotonic reasoning, as defined by Kraus, Lehmann and Magidor. We give a tableau proof procedure for all KLM logics, namely preferential, loop-cumulative, cumulative and rational logics. Our calculi are obtained by introducing suitable modalities to interpret conditional assertions. We provide a decision procedure for the logics considered, and we study their complexity.54 pages + appendix with proofsLogic in Computer ScienceArtificial IntelligenceF.4.1; I.2.3text