On the logic for utopia

In this study we propose the standard modal logic KD43 as the logle governing expressions about Utopia. We define a formal construction corresponding to Utopian expressions In ordlnary language that we name utopian eonditionals. They possess the singular properties of admitting Strengthening of the Antecedent whlle possibly defeating the rule of Modus Ponens. Perhaps the most interesting aspect of this work is that, as far as the authors know, this is the first time a category of expressions in the ordinary language corresponding to these two singular properties is provided.Eje: 2do. Workshop sobre aspectos teóricos de la inteligencia artificialRed de Universidades con Carreras en Informática (RedUNCI

On the logic for utopia

In this study we propose the standard modal logic KD43 as the logle governing expressions about Utopia. We define a formal construction corresponding to Utopian expressions In ordlnary language that we name utopian eonditionals. They possess the singular properties of admitting Strengthening of the Antecedent whlle possibly defeating the rule of Modus Ponens. Perhaps the most interesting aspect of this work is that, as far as the authors know, this is the first time a category of expressions in the ordinary language corresponding to these two singular properties is provided.Eje: 2do. Workshop sobre aspectos teóricos de la inteligencia artificialRed de Universidades con Carreras en Informática (RedUNCI

Modeling Belief in Dynamic Systems, Part II: Revision and Update

The study of belief change has been an active area in philosophy and AI. In recent years two special cases of belief change, belief revision and belief update, have been studied in detail. In a companion paper (Friedman & Halpern, 1997), we introduce a new framework to model belief change. This framework combines temporal and epistemic modalities with a notion of plausibility, allowing us to examine the change of beliefs over time. In this paper, we show how belief revision and belief update can be captured in our framework. This allows us to compare the assumptions made by each method, and to better understand the principles underlying them. In particular, it shows that Katsuno and Mendelzon's notion of belief update (Katsuno & Mendelzon, 1991a) depends on several strong assumptions that may limit its applicability in artificial intelligence. Finally, our analysis allow us to identify a notion of minimal change that underlies a broad range of belief change operations including revision and update.Comment: See http://www.jair.org/ for other files accompanying this articl