Public Announcements for Epistemic Models and Hypertheories

摘要

Artemov has recently proposed a modernization of the semantics and proof theory of epistemic logic. We take up his approach and extend his framework with public announcements and the corresponding belief change operation. We establish a soundness and completeness result and show that our model update operation satisfies the AGM postulate of minimal change. Further, we also show that the standard approach cannot be directly employed to capture knowledge change by truthful announcements.