collaborators

8 papers

math.CT2026

On Models of the Planar Lambda Calculus

Chad Nester

We construct an adjunction relating two approaches to modelling the planar lambda calculus: semi-closed operads and planar lambda-models. We use this to obtain a planar version of…

math.CT2026

Override and Update in Restriction Categories

Jean-Simon Pacaud Lemay, Chad Nester

We study the override and update operators on partial functions from the perspective of restriction categories. We propose a definition of override restriction categories, in which…

math.CT2026

A Simple Categorical Calculus of Interacting Processes

Chad Nester, Niels Voorneveld

We present a calculus that models a simple sort of process interaction. Our calculus consists of a collection of terms together with a rewrite relation, parameterised by an arbitra…

cs.LO2026

Monoidal categories graded by partial commutative monoids

Matthew Earnshaw, Chad Nester, Mario Román

Effectful categories have two classes of morphisms: pure morphisms, which form a monoidal category; and effectful morphisms, which can only be combined monoidally with central morp…

math.CT2025

A Structural Account of Combinatory Completeness

Ivan Kuzmin, Chad Nester, Ülo Reimaa +1

We give a general notion of combinatory completeness with respect to a faithful cartesian club and use it systematically to obtain characterisations of a number of different kinds…

math.CT2025

Dynamics and Coherence for the Free Cornering with Protocol Choice

Chad Nester, Niels Voorneveld

We present a term rewriting system that models the dynamic aspects of the free cornering with protocol choice of a monoidal category, which has been proposed as a categorical model…

cs.LO2025

Resourceful Traces for Commuting Processes

Matthew Earnshaw, Chad Nester, Mario Román

We show that, when the actions of a Mazurkiewicz trace are considered not merely as atomic (i.e., mere names) but transformations from a specified type of inputs to a specified typ…

math.CT2025

Elgot Categories and Abacus Programs

Chad Nester

We introduce Elgot categories, a sort of distributive monoidal category with additional structure in which the partial recursive functions are representable. Moreover, we construct…