10th International Workshop on Confluence
23rd July 2021, online (originally: Buenos Aires, Argentina)

IWC 2021

10th International Workshop on Confluence

23rd July 2021, online
(originally: Buenos Aires, Argentina)

Colocated with FSCD


Confluence provides a general notion of determinism and has been conceived as one of the central properties of rewriting systems. Confluence relates to many topics of rewriting (completion, modularity, termination, commutation, etc.) and has been investigated in many formalisms of rewriting, such as first-order rewriting, lambda-calculi, higher-order rewriting, constraint rewriting, conditional rewriting, and so on. Recently there is a renewed interest in confluence research, resulting in new techniques, tool support, confluence competition, and certification as well as in new applications. The scope of the workshop is all these aspects of confluence and related topics.

The goal of the workshop is to provide a forum for researchers interested in the topic of confluence to exchange and share new developments in the field. The workshop will enable discussion on theoretical results, new problems, applications, implementations and benchmarks, and share the current state-of-the-art on the development of confluence tools.

The 10th Confluence Competition CoCo 2021 will run live during IWC 2021.


Important Dates

submission (abstract): Monday, April 19th, 2021
submission (paper): Monday, April 26th, 2021
notification: Monday, May 31st, 2021
final version: Monday, June 14th, 2021
workshop: Friday, July 23rd, 2021

(deadlines are AoE)

Accepted papers

The proceedings are available online and include reports on the 10th Confluence Competition. You can also find individual papers below:


All times are indicated in GMT-3 (= time in Buenos Aires).

06:30 - 07:30 Jesper Cockx: The quest for modular confluence of rewrite rules in type theory

07:30 - 08:00 Break

08:00 - 08:30 Vincent van Oostrom: Multi-redexes and multi-treks induce residual systems; least upper bounds and left-cancellation up to homotopy
08:30 - 09:00 Andrew Kenyon-Roberts: A Confluent Trace Semantics for Probabilistic Lambda Calculus
09:00 - 09:30 Claudia Faggian, Giulio Guerrieri and Riccardo Treglia: Evaluation in the computational calculus is non-confluent
09:30 - 10:00 Benjamin Dupont, Philippe Malbos and Isaac Ren: Completion of operadic rewriting systems by Gaussian elimination

10:00 - 10:30 Break

10:30 - 11:30 10th Confluence Competition - CoCo 2021
11:30 - 12:00 Alexander Lochmann, Fabian Mitterwallner and Aart Middeldorp: Formalized Signature Extension Results for Confluence, Commutation and Unique Normal Forms

12:00 - 12:30 Break

12:30 - 13:30 José Meseguer: Proving Ground Confluence of Equational Programs
13:30 - 14:00 Uran Meha: Confluence in string rewriting systems compatible with a crystal structure
14:00 - 14:30 Lars Hellström: Wrap ambiguities and how to enumerate them

Invited Speakers

Program Committee

Previous IWCs


Samuel Mimram: samuel.mimram(at)lix.polytechnique.fr
Camilo Rocha: camilo.rocha(at)javerianacali.edu.co