Exploring the power of converse events

Guillaume Aucher (1) , Andreas Herzig (2)

1 ICR - Individual and Collective Reasoning
2 IRIT - Institut de recherche en informatique de Toulouse

Dynamic epistemic logic as viewed by Baltag, Moss and Solecki (DEL) and propositional dynamic logic (PDL) offer different semantics of events. On the one hand, DEL adds dynamics to epistemic logic by introducing so-called event 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. In this paper 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: it enables us to translate the structure of the event model directly within a particular axiomatization of EDL, without having to refer to a particular epistemic event model in the language (as done in DEL). It follows that EDL is more expressive and general than DEL and we characterize semantically and syntactically in EDL this embedding of DEL.

Domaines: Logique en informatique [cs.LO]

Guillaume Aucher, Andreas Herzig. Exploring the power of converse events. Dynamic formal epistemology, Springer, pp.51-74, 2011. ⟨hal-00557002v1⟩