This paper presents a new modal logic for ceteris paribus preferences understood in the sense of "all other things being equal". This reading goes back to the seminal work of Von Wright in the early 1960's and has returned in computer science in the 1990's and in more abstract "dependency logics" today. We show how it differs from ceteris paribus as "all other things being normal", which is used in contexts with preference defeaters. We provide a semantic analysis and several completeness theorems. We show how our system links up with Von Wright's work, and how it applies to game-theoretic solution concepts, to agenda setting in investigation, and to preference change. We finally consider its relation with infinitary modal logics.

No abstract

No abstract

This paper introduces a new technique for the veritication of interactive systems.It first presents the use of a model oriented formal method for specifying interactive systems, i.e. the B method. Then, it suggests formally based solutions which allow solving dimculties that are inherent to interactive systems specification, like reach ability, observability or reliability. Our claim is that this model-oriented technique that uses proof obligations can be used together with model checking techniques, where automatic proofs of properties can be performed.