collaborators

7 papers

math.LO2026

Fischer-Servi logic does not have interpolation

Rodrigo Nicolau Almeida, Nick Bezhanishvili, Simon Lemal

We prove that the Fischer-Servi logic does not have the (Craig) interpolation property. This is obtained by showing that the corresponding class of modal Heyting alge…

math.LO2026

Superamalgamation for modal lattices via non-distributive dualities

Rodrigo Nicolau Almeida, Nick Bezhanishvili, Simon Lemal

We show that the variety of modal lattices has the superamalgamation property. As a consequence, we obtain that the weak positive modal logic has the Craig interpolation property.…

cs.LO2026

Modal Fragments

Nick Bezhanishvili, Balder ten Cate, Arunavo Ganguly +1

We survey systematic approaches to basis-restricted fragments of propositional logic and modal logics, with an emphasis on how expressive power and computational complexity depend…

math.LO2025

Esakia order-compactifications and locally Esakia spaces

Rodrigo Nicolau Almeida, Guram Bezhanishvili, Nick Bezhanishvili

We introduce Esakia order-compactifications and study how they fit in the general theory of Priestley order-compactifications. We provide an analog of Dwinger's theorem by characte…

cs.LO2025

Six Proofs of Interpolation for the Modal Logic K

Nick Bezhanishvili, Balder ten Cate, Rosalie Iemhoff

In this chapter, we present six different proofs of Craig interpolation for the modal logic K, each using a different set of techniques (model-theoretic, proof-theoretic, syntactic…

math.LO2025

Pre-filtrations, Pre-stable Canonical Rules, and the Kuznetsov-Muravitsky Isomorphism

Nick Bezhanishvili, Antonio Maria Cleani

We introduce pre-filtration and pre-stable canonical rules for the Kuznetsov-Muravitsky system of intuitionistic modal logic and provide a new proof of the Kuznetsov-Muravitsky iso…