LIRa Session: Malvin Gattinger

Speaker: Malvin Gattinger (University of Groningen)

Date and Time: Thursday, April 4th 2019, 16:30-18:00

Venue: ILLC Seminar Room F1.15, Science Park 107.

Title: Adding Boolean Definitions to Public Announcement Logic.

Abstract. In standard epistemic logic, knowing p means to know that p is true, not saying anything about understanding p. In this talk I will present joint work with Yanjing Wang where we extend PAL to address this limitation.

We define the meaning of propositions with boolean formulas and add an operator for `equivalence by definition’ to the language. We can then model agents with different knowledge or belief about both the truth value and the meaning of propositions. For example, an agent may understand a proposition without knowing its truth value or the other way round. Moreover, multiple agents might agree that something is true without agreeing on its meaning and vice versa.

The talk will include various examples and a sketch of the completeness proof. It should be accessible to everyone with some background in epistemic logic.