Abstract

Since Plaza [1989], which is most of the time considered as the inaugural paper on announcement logics in public communication contexts, a lot of papers on dynamic epistemic logics have been published. The most famous dynamic epistemic logic is known by the name of PAL (Public Announcement Logic). The logic PAC is an extension of PAL with the common knowledge operator (CG). Soundness and completeness proofs of those logics are presented in van Ditmarsch et al. [2008], in Balbiani et al. [2010] and in de Boer [2007]. Each of them used either a model-theoretic approach or a tableaux calculus. In the present paper, we propose an alternative approach to PAC based on the dialogical framework