Term Assignment and Categorical Models for Intuitionistic Linear Logic with Subexponentials
Daniel Rogozin
TL;DR
This work addresses grounding intuitionistic linear logic with multiple subexponentials in a unified syntactic and semantic framework. It introduces ${\bf SILL}(\lambda)_{\Sigma}$, a typed lambda calculus with a subexponential signature ${\Sigma}$, proves strong normalisation and confluence for $β$-reduction using a Girard-style computability approach, and develops a categorical semantics based on Cocteau categories and ${\Sigma}$-assemblages. The paper further characterises relevant categories via copying, realises resource modalities from adjunctions, and connects these to Lafont categories, providing a robust 2-categorical account of the models. The results lay a foundation for resource-aware programming languages with structured modal policies and give tools for future realisability and dependent-type extensions in linear logic.
Abstract
In this paper, we present a typed lambda calculus ${\bf SILL}(λ)_Σ$, a type-theoretic version of intuitionistic linear logic with subexponentials, that is, we have many resource comonadic modalities with some interconnections between them given by a subexponential signature. We also give proof normalisation rules and prove the strong normalisation and Church-Rosser properties for $β$-reduction by adapting the Tait-Girard method to subexponential modalities. Further, we analyse subexponentials from the point of view of categorical logic. We introduce the concepts of a Cocteau category and a $Σ$-assemblage to characterise models of linear type theories with a single exponential and affine and relevant subexponentials and a more general case respectively. We also generalise several known results from linear logic and show that every Cocteau category and a $Σ$-assemblage can be viewed as a symmetric monoidal closed category equipped with a family of monoidal adjunctions of a particular kind. In the final section, we give a stronger 2-categorical characterisation of Cocteau categories.
