UCL Discovery
UCL home » Library Services » Electronic resources » UCL Discovery

String diagram rewrite theory II: Rewriting with symmetric monoidal structure

Bonchi, Filippo; Gadducci, Fabio; Kissinger, Aleks; Sobocinski, Pawel; Zanasi, Fabio; (2022) String diagram rewrite theory II: Rewriting with symmetric monoidal structure. Mathematical Structures in Computer Science , 32 (4) pp. 511-541. 10.1017/S0960129522000317. Green open access

[thumbnail of string-diagram-rewrite-theory-ii-rewriting-with-symmetric-monoidal-structure.pdf]
Preview
Text
string-diagram-rewrite-theory-ii-rewriting-with-symmetric-monoidal-structure.pdf - Published Version

Download (515kB) | Preview

Abstract

Symmetric monoidal theories (SMTs) generalise algebraic theories in a way that make them suitable to express resource-sensitive systems, in which variables cannot be copied or discarded at will. In SMTs, traditional tree-like terms are replaced by string diagrams, topological entities that can be intuitively thought of as diagrams of wires and boxes. Recently, string diagrams have become increasingly popular as a graphical syntax to reason about computational models across diverse fields, including programming language semantics, circuit theory, quantum mechanics, linguistics, and control theory. In applications, it is often convenient to implement the equations appearing in SMTs as rewriting rules. This poses the challenge of extending the traditional theory of term rewriting, which has been developed for algebraic theories, to string diagrams. In this paper, we develop a mathematical theory of string diagram rewriting for SMTs. Our approach exploits the correspondence between string diagram rewriting and double pushout (DPO) rewriting of certain graphs, introduced in the first paper of this series. Such a correspondence is only sound when the SMT includes a Frobenius algebra structure. In the present work, we show how an analogous correspondence may be established for arbitrary SMTs, once an appropriate notion of DPO rewriting (which we call convex) is identified. As proof of concept, we use our approach to show termination of two SMTs of interest: Frobenius semi-algebras and bialgebras.

Type: Article
Title: String diagram rewrite theory II: Rewriting with symmetric monoidal structure
Open access status: An open access version is available from UCL Discovery
DOI: 10.1017/S0960129522000317
Publisher version: http://doi.org/10.1017/S0960129522000317
Language: English
Additional information: © The Author(s), 2022. Published by Cambridge University Press. This is an Open Access article, distributed under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike licence (http://creativecommons.org/licenses/by-nc-sa/4.0), which permits non-commercial re-use, distribution, and reproduction in any medium, provided the same Creative Commons licence is used to distribute the re-used or adapted article and the original article is properly cited. The written permission of Cambridge University Press must be obtained prior to any commercial use.
Keywords: String diagram, symmetric monoidal category, double-pushout
UCL classification: UCL
UCL > Provost and Vice Provost Offices > UCL BEAMS
UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Engineering Science
UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Engineering Science > Dept of Computer Science
URI: https://discovery.ucl.ac.uk/id/eprint/10160500
Downloads since deposit
24Downloads
Download activity - last month
Download activity - last 12 months
Downloads by country - last 12 months

Archive Staff Only

View Item View Item