PAC vs. DEMAL. A Dialogical Reconstruction of Public Announcement Logic with Common Knowledge: A Dialogical Reconstruction of Public Announcement Logic with Common Knowledge

Abstract : Since the work of Plaza (1989) about acts of public communication, a lot of dynamic epistemic logic systems have emerged. A general state of the art can be found in van Ditmarsch et al. (2007). Such logics model situations in which some announcements can be made and after an announcement, the situations which are incompatible with it are deleted from the model. In this paper we propose a reconstruction of the logic PAC (Public Announcement logic with Common Knowledge, see van Ditmarsch et al. (2007)) through the dialogical framework. The idea of this work is to rediscover announcements as acts: acts of an arguer during an argumentative dialogue about knowledge change of agents instead of "model-modifiers". We name this reconstruction DEMAL for Dialogical Epistemic Multi-Agent Logic.