Very weak subintuitionistic logics
Logic
2026-05-21 v1
Abstract
We introduce a new propositional logic, called very weak subintuitionistic logic , by adapting the relational semantics of Fitting, Marek, and Truszczy\'nski for the pure logic of necessitation to the propositional setting. We prove that and its closed negative extensions are sound and complete with respect to this semantics, and that they have the disjunction property and the finite frame property. We also prove that is strictly weaker than the weak subintuitionistic logic of Shirmohammadzadeh Maleki and de Jongh. Finally, we study modal companions of and its closed negative extensions via Corsi's modified G\"odel translation.
Keywords
Cite
@article{arxiv.2605.20769,
title = {Very weak subintuitionistic logics},
author = {Taishi Kurahashi and Mashu Noguchi},
journal= {arXiv preprint arXiv:2605.20769},
year = {2026}
}
Comments
22 pages