This paper reports on an approach tomodel generalized implicatures using nonmonotonic logics. The approach, called compositional, is based on the idea of compositional semantics, where the implicatures carried by a sentence are constructed from the implicatures carried by its constituents, but it also includes some aspects nonmonotonic logics in order to model the defeasibility of generalized i...

One of the main tools in the study of nonmonotonic consequence relations is the representation of such relations in terms of preferential models. In this paper we give an unified and simpler framework to obtain such representation theorems.

We consider the problem of a society whose members must choose from a …nite set of alternatives. After knowing the chosen alternative, members may reconsider their membership by either staying or exiting. In turn, and as a consequence of the exit of some of its members, other members might now …nd undesirable to belong to the society as well. For general exit procedures we analyze the exit beha...

We present an alternative int’erpretation of defaults which draws on probability theory and notions of relevance. The result is a syst,em made up of a body of six rules which appears t’o overcome some of the weaknesses of other non-monotonic logics proposed in AI. We also analyze several examples and discuss some of the issues t#hat require further research.

We consider a ballistic random walk in an i.i.d. random environment that does not allow retreating in a certain fixed direction. Homogenization and regeneration techniques combine to prove a law of large numbers and an averaged invariance principle. The assumptions are non-nestling and 1 + ε (resp. 2 + ε) moments for the step of the walk uniformly in the environment, for the law of large number...

We investigate several technical and conceptual questions. Our main subject is the investigation of independence as a ternary relation in the context of non-monotonic logic. In the context of probability, this investigation was started by W.Spohn et al., and then followed by J.Pearl. We look at products of function sets, and thus continue our own investigation of independence in non-monotonic l...