Knowledge forgetting: Properties and applications

In this paper we study a formal notion of knowledge forgetting in S5 modal logic. We propose four postulates and prove that these postulates precisely characterize both semantic and logical properties of knowledge forgetting. We then investigate possible applications of knowledge forgetting in various epistemic reasoning scenarios. In particular, we show that different forms of knowledge updates may be represented via knowledge forgetting. We also demonstrate how knowledge forgetting can be used in formalizing and reasoning about knowledge games with bounded memory.