Private Expansion and Revision in Multi-agent Settings

AGM belief change aims at modeling the evolution of an agent's beliefs about its environment. In many applications though, a set of agents sharing the same environment must be considered. For such scenarios, beliefs about other agents' beliefs must be taken into account. In this work, we study private expansion and revision operators in such a multi-agent setting. More precisely, we investigate the changes induced by a new piece of information made available to one agent in the set. We point out an adaptation of AGM expansion and revision postulates to this setting, and present expansion and revision operators.