Caros, Na quinta dia 04/04 receberemos na UFRJ o pesquisador Ivan José Varzinczak, CAIR, the UKZN-CSIR Meraka Centre for Artificial Intelligence Research, in South Africa. * *Ivan José Varzinczak received his *Ph.D. in Artificial Intelligence* from Université Paul Sabatier, France, in 2006. Former member of IRIT, France, he is currently a postdoctoral researcher at CAIR, the UKZN-CSIR Meraka Centre for Artificial Intelligence Research, in South Africa. * http://en.varzinczak.net16.net/
*Todos são muito benvindos. Um abraço, Mario* *Benevides* Local: *PESC-COPPE, sala H324*A Data: *18/03 Hora: 12:45* Título*: Defeasible Modalities *Resumo*: Nonmonotonic logics are usually characterized by the presence of some notion of `conditional' that fails monotonicity. Research on nonmonotonic logics is therefore largely concerned with the defeasibility of argument forms and the associated normality (or abnormality) of its constituents. In contrast, defeasible modes of inference aim to formalize the defeasible aspects of modal notions such as actions, obligations and knowledge. In this work we enrich the standard possible worlds semantics with a preference ordering on worlds in Kripke models. The resulting family of modal logics allow for the elegant expression of defeasible modalities. We also propose a tableau calculus which is sound and complete with respect to our preferential semantics. -- Federal University of Rio de Janeiro www.cos.ufrj.br/~mario _______________________________________________ Logica-l mailing list [email protected] http://www.dimap.ufrn.br/cgi-bin/mailman/listinfo/logica-l
