3 papers
math.LO2026
Most properties are undecidable even in
Qian Chen, Tenyo Takahashi
We investigate decidability of properties in the lattice of extensions of the Grzegorczyk tense logic and the lattice $\mat…
math.LO2025
Decidability of Being a Union-splitting
Tenyo Takahashi
Many logical properties are known to be undecidable for normal modal logics, with few exceptions such as consistency and coincidence with . This paper shows that the pr…
math.LO2025
Stable Canonical Rules and Formulas for Pre-transitive Logics via Definable Filtration
Tenyo Takahashi
We generalize the theory of stable canonical rules by adopting definable filtration, a generalization of the method of filtration. We show that for a modal rule system or a modal l…