New Modification of the Subformula Property for a Modal Logic
A modified subformula property for the modal logic KD with the additional axiom □ ◊(A ∨ B) ⊃ □ ◊ A ∨ □ ◊B is shown. A new modification of the notion of subformula is proposed for this purpose. This modification forms a natural extension of our former one on which modified subformula property for the...
| Main Author: | |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Lodz University Press
2020-11-01
|
| Series: | Bulletin of the Section of Logic |
| Subjects: | |
| Online Access: | https://czasopisma.uni.lodz.pl/bulletin/article/view/6148 |
| Summary: | A modified subformula property for the modal logic KD with the additional
axiom □ ◊(A ∨ B) ⊃ □ ◊ A ∨ □ ◊B is shown. A new modification of the notion of subformula is proposed for this purpose. This modification forms a natural extension of our former one on which modified subformula property for the modal logics K5, K5D and S4.2 has been shown ([2] and [4]). The finite model property as well as decidability for the logic follows from this. |
|---|---|
| ISSN: | 0138-0680 2449-836X |