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An online session of the Algebra and Logic Seminar will be held on November 26, 2021 (Friday) at 1:00 p.m. (UTC +2).

A talk on

On a method of proving the non-existence of modal formulae satisfying certain syntactic properties and defining a given class of frames

will be delivered by Petar Iliev (Institute of Philosophy and Sociology and Institute of Mathematics and Informatics, Bulgarian Academy of Sciences).

Abstract. 

We elaborate on semantically labeled syntax trees, which provide a method of proving the non-existence of modal formulae satisfying certain syntactic properties and defining a given class of either models or frames, and use them to show that there are classes of Kripke frames that are definable by both non-Sahlqvist and Sahlqvist formulae but the latter require more propositional variables.

The talk is based on the following articles.

P. Iliev. On a method of proving the non-existence of modal formulae
satisfying certain syntactic properties and defining a given class of frames (submitted).

P. Balbiani, D. Fernandez-Duque, A. Herzig, and P. Iliev. Frame validity Games and Lower Bounds on the Complexity of Modal Axioms. Logic Journal of the IGPL (2020).

 

The seminar will be held via Zoom and everyone can join at:

https://us02web.zoom.us/j/85137375021?pwd=RE5QczdFTE1xL1R6MnI2b1lkcGczQT09 

Topic: Онлайн семинар на секция “Алгебра и логика”
Time: Nov 26, 2021 01:00 PM Sofia
Meeting ID: 851 3737 5021
Passcode: 035647

Algebra and Logic Department, IMI-BAS
http://www.math.bas.bg/algebra/seminarAiL/
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