Reasoning about information change

Abstract

In this paper we introduce Dynamic Epistemic Logic, which is a logic for reasoning about information change in a multi-agent system. The information structures we use are based on non-well-founded sets, and can be conceived as bisimulation classes of Kripke models. On these structures, we define a notion of information change that is inspired by Update Semantics (Veltman, 1996). We give a sound and complete axiomatization of the resulting logic, and we discuss applications to the puzzle of the dirty children, and to knowledge programs. © 1997 Kluwer Academic Publishers.