Termination Competition

Annual International Termination Competition

During the 90's a number of new, powerful termination methods was developed. Thus, at the beginning of the millennium many research groups started to develop tools for fully-automated termination analysis.

After a tool demonstration at the Termination Workshop 2003 (Valencia), the community then decided to install an annual termination competition, and to collect benchmarks, to spur the development of tools and new termination techniques.

Upcoming Competitions

• The Termination Competition 2024 will be held during IJCAR 2024, July 1-6, Nancy, France.

Organization

Questions and suggestions regarding the competition should go to the termtools mailing list. Discussion is open and happens primarily on the list. Decisions will be made by votes among the Termination Competition Steering Committee, with current members

• Florian Frohn (Chair), RWTH Aachen
• Jürgen Giesl, RWTH Aachen
• Georg Moser, University of Innsbruck
• Étienne Payet, Université de La Réunion
• Akihisa Yamada, AIST Tokyo Waterfront

From 2004 till 2007, the competition organizer was Claude Marché, Paris. From 2008 to 2013 the competition was run by René Thiemann, Innsbruck. From 2014 to 2017, the competition organizer was Johannes Waldmann. Jobs were run on the Star Exec platform at U Iowa. From 2018 to 2023, the organizer was Akihisa Yamada. From 2024 on, the organizer is Florian Frohn. Jobs are run on Star-Exec.

Competition Categories

Currently, the competition features the following categories:

• termination of string and term rewriting
• termination of logic programs
• certified termination of string and term rewriting (since 2007)
• termination of functional programs (since 2007)
• complexity of rewrite systems (since 2008)
• termination of Java Bytecode programs (since 2009)
• termination of higher order rewriting (since 2010)
• termination of C programs (since 2014)
• complexity of C programs
• termination of integer transition systems (since 2014)
• integer term rewriting (since 2014)
• termination of cycle rewriting
• termination of probabilistic term rewriting (since 2024)

Termination Problems Data Base

The Termination Problems Data Base collects all the problems used in the competitions.

We welcome problem submissions from non-participants.

History of Termination Competitions

The following competitions have taken place:

• Termination Competition 2024 affiliated with IJCAR 2024, Results.
• Termination Competition 2023 affiliated with WST2023, Results.
• Termination Competition 2022 affiliated with IJCAR 2022, Results.
• Termination Competition 2021 affiliated with CADE 2021, Results.
• Termination Competition 2020 affiliated with IJCAR 2020, Results.
• Termination Competition 2019 affiliated with Toolympics at TACAS 2019, Results.
• Termination Competition 2018 affiliated with FLoC 2018, Oxford, UK, July 13, 2018, Results.

• Termination Competition 2017 affiliated with FSCD, Results of Competition, Results of demonstration.

• Termination Competition 2016 affiliated with WST (Workshop on Termination), Results of Competition. Presentation at WST

• Termination Competition 2015, Results of Competition, Description paper at CADE-25 Report

• Termination Competition 2014, Results of Competition, Results of Demonstration

• Termination Competition 2013, Results, Report

• Termination Competition 2012, Results, Report

• Termination Competition 2011, Results, Report

• Termination Competition 2010, Results

• Termination Competition 2009 Results, Announcement

• Termination Competition 2008, Results, Report
• Termination Competition 2007, Report
• Termination Competition 2006, Report
• Termination Competition 2005, Report
• Termination Competition 2004, Report

At the "tool demonstration" in 2003, participating provers (including AProVe, Torpa, Matchbox) were run on the laptop computers of their developers in the room. Termination problems were announced on the spot by participants, then written on the blackboard, then typed in by everyone, and when a team's program could solve it, they shouted "solved".

Static Backups of Results

For many previous competitions, static backups of the results are available here.