9th International Workshop on Confluence
30th June 2020, Paris, France

IWC 2020

9th International Workshop on Confluence

30th June 2020, Paris, France

Colocated with FSCD and IJCAR



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.

IWC 2020 is part of Paris Nord Summer of LoVe 2020, a joint event on LOgic and VErification at Université Paris 13, made of Petri Nets 2020, IJCAR 2020, FSCD 2020, and over 20 satellite events.

The 9th Confluence Competition CoCo 2020 will run live during IWC 2020.


Important Dates

submission (abstract): Friday, April 17th, 2020
submission (paper): Wednesday, April 22nd, 2020
notification: Friday, May 22nd, 2020
workshop: Tuesday, June 30th, 2020

(deadlines are AoE)

Accepted papers

The proceedings are available online and include reports on the 9th Confluence Competition. You can also find individual papers below:


 9:00-10:00  Frédéric Blanqui: On the use of confluence in type theory modulo rewriting - Invited Talk (slides)
10:00-10:30 Vincent van Oostrom: Some symmetries of commutation diamonds (slides)
10:30-11:00 Kiraku Shintani and Nao Hirokawa: Parallel Closedness Revisited (slides)

11:30-12:00 Benjamin Dupont, Philippe Malbos and Cyrille Chenavier:
Algebraic critical pair lemma  (slides)
12:00-12:30 Ugo De'Liguoro and Riccardo Treglia: On the reduction of the type-free
            computational Lambda-calculus (slides)
12:30-13:00 Anders Miltner, Kathleen Fisher, Benjamin Pierce, David Walker and Steve Zdancewic:
            Confluence in Lens Synthesis (slides)

14:00-15:00 9th Confluence Competition - CoCo 2020 - (slides)
            Report presented by Aart Middeldorp, Kiraku Shintani, Naoki Nishida and Johannes Waldmann
15:00-15:30 Cameron Calk: Coherent Confluence in Modal n-Kleene Algebras (slides)

16:00-17:00  Margherita Zorzi: Compositional theories for embedded programming - Invited Talk  (slides)

17:00-17:30 Eelco Visser and Eduardo Amorim: Safety and Completeness of Disambiguation corresponds
            to Termination and Confluence of Reordering (slides)
17:30-18:00 Jean-Pierre Jouannaud and Fernando Orejas: Confluence of drag rewriting  (slides)
18:00-18:05 Closing and Announcement of the IWC SC by Takahito Aoto (slides)

Some screen shots: sc01 sc02 sc03 sc04 sc05 sc06 sc07 sc08 sc09 sc10 sc11 sc12

Unedited Live Broadcast

Invited Speakers

Program Committee

Previous IWCs


Mauricio Ayala-Rincón: ayala(at)unb.br
Samuel Mimram: samuel.mimram(at)lix.polytechnique.fr