From DEL to EDL : Exploring the Power of Converse Events

Dynamic epistemic logic (DEL) as viewed by Baltag et col. and propositional dynamic logic (PDL) offer different semantics of events. On the one hand, DEL adds dynamics to epistemic logic by introducing so-called epistemic action models as syntactic objects into the language. On the other hand, PDL has instead transition relations between possible worlds. This last approach allows to easily introduce converse events. We add epistemics to this, and call the resulting logic epistemic dynamic logic (EDL). We show that DEL can be translated into EDL thanks to this use of the converse operator: this device enables us to translate the structure of the action (or event) model directly within a particular axiomatization of EDL, without having to refer to a particular epistemic action (event) model in the language (as done in DEL). It follows that EDL is more expressive and general than DEL.

• Type: Conference
• Year: 2007
• Where: ECSQARU
• Authors: Guillaume Aucher, Andreas Herzig
• Keywords: ECSQARU 2007, Epistemic, Epistemic Action, Epistemic Logic