Minimal Models, Characteristic Formulas and Public Announcements: Talking about Truths at Possible Worlds
Minimal Models, Characteristic Formulas and Public Announcements: Talking about Truths at Possible Worlds

Summary/Abstract: The first half of this paper is expository, its main purpose being to introduce different notions of the model theory of modal logic (mainly the ones related to the notion of bisimulation) to philosophers. The second half will be concerned with introducing the framework of Public Announcement Logic (independently discovered by J. Plaza and J. Gerbrandy) and showing how we can talk at a certain possible world about truths at other worlds in this new logical setting. Although this can be done successfully in Hybrid Logic, the new logical apparatus will offer a solution that does not involve accepting ”nominals”(propositional atoms that denote possible worlds). Also, using this new way of talking about truths at possible worlds, I will present a formula that states at a possible world that the model is maximally contracted.

• Details
• Contents