Title:
Public announcement games

Author:
Hans van Ditmarsch
(chercheur à l'Université de Seville et professeur invité a l'Université
Paris Dauphine).

Abstract:
In dynamic epistemic logic we can precisely describe what the requirements and
consequences of informative actions are. In particular, public announcement
logic describes actions in the form of public, truthful announcements.
Announcements of the form that the agent knows a proposition can be seen as
announced by that agent. But before she has made that announcement, there may
be different announcements that she could have chosen to make. We discuss what
rational agents should do if they can choose between different actions. We
consider situations where each agent has a goal formula that she would like to
become true, and where the available actions are public announcements. What
will each agent announce, assuming common knowledge of the situation? The truth
of the goal formula after the agent's announcement depends on the announcements
made by other agents, hence we have a game theoretic scenario. We discuss
properties of such public announcement games.

There are some further developments towards games consisting of questions and
answers, and game languages expressing abilities of groups of collaborating
players.