Semantic results for ontic and epistemic change

We present an epistemic logic incorporating dynamic operators to describe information changing events. Such events include epistemic changes, where agents become more informed about the non-changing state of the world, and ontic changes, wherein the world changes. The events are executed in information states that are modelled as pointed Kripke models. Our contribution consists of three semantic results. (i) Every consistent formula can be made true in every information state by the execution of an event. (ii) Every event corresponds to an event with assignments to true and false only. (iii) Every event corresponds to a sequence of events with assignments of a single atom only. We apply the logic to model dynamics in a multi-agent setting involving card players.

• Type: Journal
• Year: 2006
• Where: CORR
• Authors: Hans P. van Ditmarsch, Barteld P. Kooi
• Keywords: CORR 2006, Dynamic Operators, Education, Epistemic Changes, Epistemic Logic