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arXiv · 2507.11644

Reopening of the conjecture about the decidability of Quasi-Dense Modal Logics (Comments on Lyon & Ostropolski-Nalewaja's result)

Olivier Gasquet
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Abstract

In \cite{Lyon24} the question of the decidability of quasi-dense modal logics is answered, and an upper bound in $\EXPSPACE$ is given. Unfortunately, authors' intricate proof seems to contain a major flaw that cannot be fixed, leaving the question wide open.

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Olivier Gasquet. 2025-07-15. Reopening of the conjecture about the decidability of Quasi-Dense Modal Logics (Comments on Lyon & Ostropolski-Nalewaja's result). https://arxiv.org/abs/2507.11644

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