Semantical Proof of Subformula Property for the Modal Logics K4.3, KD4.3, and S4.3

• Autorzy: Daishi Yazaki
• Języki publikacji: EN

Abstrakty

EN

The main purpose of this paper is to give alternative proofs of syntactical and semantical properties, i.e. the subformula property and the nite model property, of the sequent calculi for the modal logics K4.3, KD4.3, and S4.3. The application of the inference rules is said to be acceptable, if all the formulas in the upper sequents are subformula of the formulas in lower sequent. For some modal logics, Takano analyzed the relationships between the acceptable inference rules and semantical properties by constructing models. By using these relationships, he showed Kripke completeness and subformula property. However, his method is difficult to apply to inference rules for the sequent calculi for K4.3, KD4.3, and S4.3. Lookinglosely at Takano's proof, we nd that his method can be modied to construct nite models based on the sequent calculus for K4.3, if the calculus has (cut) and all the applications of the inference rules are acceptable. Similarly, we can apply our results to the calculi for KD4.3 and S4.3. This leads not only to Kripke completeness and subformula property, but also to finite model property of these logics simultaneously.

Słowa kluczowe

EN

modal logic; analytic cut; subformula property; finite model property

• Wydawca: Wydawnictwo Uniwersytetu Łódzkiego
• Czasopismo: Bulletin of the Section of Logic
• Rocznik: 2019
• Tom: 48
• Numer: 4

Daty

wydano

2019-12-31

Twórcy

autor

Daishi Yazaki

• Graduate School of Science and Technology, Shizuoka University, Japan

Bibliografia

• [1] T. Shimura, Cut-free system for modal logic S4.3 and S4.3Grz, Reports on Mathematical Logic, Vol. 25 (1991), pp. 57–73.
• [2] M. Takano, A modied subformula property for the modal logics K5 and K5D, Bulletin of the Section of Logic, Vol. 30 (2001), pp. 115–122.
• [3] M. Takano, A semantical analysis of cut-free calculi for modal logics, Reports on Mathematical Logic, Vol. 53 (2018), pp. 43–65. http://dx.doi.org/10.4467/20842589RM.18.003.8836

Identyfikatory

DOI

10.18778/0138-0680.48.4.01