Intuitionistic modal logic LIK4 is decidable
Philippe Balbiani, Çigdem Gencer, Tinko Tinchev
TL;DR
The paper proves the decidability of LIK4, an intuitionistic modal logic, by developing a constructive, labelled-tree based framework. It builds a canonical model, introduces a defect-repair saturation process, and demonstrates a finite frame property via regular clips and finite saturation, culminating in a finite-frame completeness result. This yields a practical decision procedure and provides structural insights into semantics and proof theory for intuitionistic modal logics. The approach also situates LIK4 within the landscape of finite-frame techniques, enabling standard decidability arguments.
Abstract
In this note, we prove that intuitionistic modal logic LIK4 is decidable.
