IWC 2015
4th International Workshop on Confluence

August 2, 2015, Berlin, Germany



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 had been investigated in many formalisms of rewriting such as first-order rewriting, lambda-calculi, higher-order rewriting, constraint rewriting, conditional rewriting, etc. 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 workshop is collocated with CADE-25. Previous editions of the workshop were held in Nagoya (2012), Eindhoven (2013) and Vienna (2014).

During the workshop the 4th Confluence Competition (CoCo 2015) takes place.


Specific topics of interest include:




Lambda Calculi and Confluence from A to Z    (invited talk)
Koji Nakazawa
Point-Decreasing Diagrams Revisited
Bertram Felgenhauer

Coffee Break

Point-Step-Decreasing Diagrams
Bertram Felgenhauer
Infeasible Conditional Critical Pairs
Thomas Sternagel and Aart Middeldorp
12:00 - 12:30
Operational Confluence of Conditional Term Rewrite Systems
Karl Gmeiner

12:30 - 14:00
Lunch Break

14:00 - 15:00
Herbrand-Confluence in the Classical Sequent Calculus    (invited talk)
Stefan Hetzl
Commutation and Signature Extensions
Nao Hirokawa

15:30 - 16:00
Coffee Break

16:00 - 16:30
Level-Confluence of 3-CTRSs in Isabelle/HOL
Christian Sternagel and Thomas Sternagel
Labeling Multi-Steps for Confluence of Left-Linear Term Rewrite Systems
Bertram Felgenhauer
Confluence Competition

Important Dates

submission May 22, 2015 (submission is now closed)
notification June 12, 2015
final version July 3, 2015
workshop August 2, 2015


We solicit short papers or extended abstracts of at most five pages. There will be no formal reviewing. In particular, we welcome short versions of recently published articles and papers submitted elsewhere. The program committee checks relevance and may provide additional feedback. The accepted papers will be made available electronically before the workshop.

The page limit for papers is 5 pages in EasyChair style. Short papers or extended abstracts must be submitted electronically through the EasyChair system at:

Organizing Committee

Invited Speakers

Program Committee