Topological square of logic S4.1

2026/07/14 by Anton Kashchenko, Andrey Kudinov
#math.LO

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Abstract

In this paper, we find the axiomatization for the topological square of S4.1. This is the first known topological square of a modal logic that differs from both the fusion and the Kripke product. We also prove the finite model property and decidability for this logic.

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