collaborators

10 papers

math.LO2026

Intuitionistic K is a Bisimulation-Invariant Fragment of Intuitionistic First-Order Logic

Jim de Groot, João Marcos, Rodrigo Stefanes

We define the notion of IK-bisimulation between the relational semantics for the intuitionistic modal logic IK, and prove that IK arises as the IK-bisimulation-invariant fragment o…

cs.LO2026

Intuitionistic Monotone Modal Logic: Proof Theory and Semantics

Tiziano Dalmonte, Jim de Groot

We study the recently introduced intuitionistic monotone modal logic IM. We first provide a semantic characterisation for a family of natural extensions of IM in terms of construct…

math.LO2026

Modal Measurable Logics via a Modal Loomis-Sikorski Representation Theorem

Nick Bezhanishvili, Jim de Groot, Lawrence S. Moss

We investigate a modal extension of the infinitary classical logic with countable meets and joins, formulated with an eye toward measure-theoretic work in dynamical systems and in…

math.LO2026

Relational Semantics for Flat Heyting-Lewis Logic

Jim de Groot, Tadeusz Litak

We introduce relational semantics for "flat Heyting-Lewis logic" HLC-flat. This logic arises as the extension of intuitionistic logic with a Lewis-style strict implication modality…

math.LO2026

Duality for Constructive Modal Logics: from Sahqlvist to Goldblatt-Thomason

Jim de Groot, Ian Shillito, Ranald Clouston

We carry out a semantic study of the constructive modal logic CK. We provide a categorical duality linking the algebraic and birelational semantics of the logic. We then use this t…

math.LO2026

Filling in the semantics for intuitionistic conditional logic

Brendan Dufty, Jim de Groot

We prove completeness results for a wide variety of intuitionistic conditional logics. We do so by first using a canonical model construction obtain completeness with respect to de…