Sesión extraordinaria del Seminario (29-10-2009): Tim French

Fecha / Date: 29-10-2009.

Hora / Time: 13:00 h.

Lugar / Location: Seminario del módulo E1 del Departamento de Ciencias de la Computación e Inteligencia Artificial, Escuela Técnica Superior de Ingeniería Informática - Universidad de Sevilla.

Ponente / Lecturer: Tim French (The University of Western Australia).

Título / Tittle: A logic for informative events.

Resumen / Abstract:
Modal logic is frequently used for modelling knowledge in multi-agent systems. The semantics of modal logic uses the notion of "possible worlds", between which an agent is unable to distinguish. In dynamic systems agents acquire new knowledge (say by an announcement, or the execution of some action) that allows to distinguish between worlds they previously could not separate. From the agents point of view, what were "possible worlds" become inconceivable. We introduce a multi-agent logic of knowledge with time where FΦ stands for 'there is an informative event after which Φ'. Formula Φ is true in a model iff it is true in all its refinements (i.e., 'atoms' and 'back' are satisfied; the dual of simulation). We investigate a correspondence between these semantics and various other dynamic epistemic logics; show the resulting logic is decidable; and provide a sound and complete axiomatization for the logic.