HOR 2019

10th International Workshop on

Higher-Order Rewriting

Dortmund, Germany

28 June 2019

affiliated with FSCD 2019


HOR is a forum to present work concerning all aspects of higher-order rewriting. The aim is to provide an informal and friendly setting to discuss recent work and work in progress. The following is a non-exhaustive list of topics for the workshop:

  • Applications: proof checking, theorem proving, generic programming, declarative programming, program transformation, automated termination/confluence tools.
  • Foundations: pattern matching, unification, strategies, narrowing, termination, syntactic properties, type theory, complexity of derivations.
  • Frameworks: term rewriting, conditional rewriting, graph rewriting, net rewriting, comparisons of different frameworks.
  • Implementation: explicit substitution, rewriting tools, compilation techniques. Semantics: semantics of higher-order rewriting, categorical rewriting, higher-order abstract syntax, games and rewriting

Informations about previous editions can be found here.


To give a presentation at the workshop, submit an extended abstract (between 2 to 5 pages} via Easychair:


HOR is a platform for discussing open questions, ongoing research, and new perspectives, as well as new results. Extended abstracts describing work in progress, preliminary results, research projects, or problems in higher-order rewriting are very welcome.

The workshop has informal electronic proceedings.

For questions regarding submission, please contact the PC chair Silvia Ghilezan.

Important Dates

  • Submission: 15 April 2019 25 April 2019 Extended
  • Notification: 17 May 2019
  • Final version: 31 May 2019
  • Workshop: 28 June 2019

Invited speakers

  • Martin Avanzini                       INRIA Sophia Antipolis Méditerranée, France
    Higher-Order Complexity Analysis With First-Order Tools
  • Joerg Endrullis                        Vrije Universiteit Amsterdam, The Netherlands
    On the Clocked Lambda-Calculus
  • Giulio Manzonetto                  Université Paris 3, France
    Degrees of extensionality in the theory of Bohm trees


Joint HOR + IWC + CoCo Proceedings can be found here.


Joint HOR + IWC Programme

Session 1 Chair: Mauricio Ayala-Rincón

  • 09:00-9:15 Welcome
  • 09:15-10:00 Invited Talk: Higher-order Termination Cynthia Kop
  • 10:00-10:30 Coffee Break

Session 2 Chair: Jakob Grue Simonsen

  • 10:30-11:00 RP IWC: Proving Non-Joinability using Weakly Monotone Algebras Bertram Felgenhauer and Johannes Waldmann
  • 11:00-11:30 RP IWC: The Diamond Lemma for non-terminating rewriting systems using deterministic reduction strategies Cyrille Chenavier and Maxime Lucas
  • 11:30-12:00 RP IWC: infChecker, a tool for checking infeasibility Raúl Gutiérrez and Salvador Lucas
  • 12:00-12:30 RP HOR: SizeChangeTool: A Termination Checker for Higher-Order Rewriting with Dependent Types Guillaume Genestier
  • 12:30-14:00 Lunch Break

Sesssion 3 Chair: Silvia Ghilezan

  • 14:00-14:45 Invited Talk: Higher-Order Complexity Analysis With First-Order Tools Martin Avanzini
  • 14:45-15:30 Invited Talk: On the Ground Confluence of Order-sorted Conditional Specifications Modulo Axioms: Maude’s Church-Rosser Checker Francisco Durán
  • 15:30-16:00 Coffee Break

Session 4 Chair: Stefano Guerrini

  • 16:00-16:45 Invited Talk: On the Clocked Lambda-Calculus Jörg Endrullis
  • 16:45-17:30 Invited Talk: Degrees of extensionality in the theory of Böhm trees Giulio Manzonetto
  • 17:30-18:00 RP IWC: Residuals Revisited Christina Kohl and Aart Middeldorp
  • 18:00-18:30 CoCo report Aart Middeldorp


Registration will be done through the FSCD registration web page.

Accommodation: information available through the FSCD web page.


Program Committee

  • Silvia Ghilezan  (Chair)            University of Novi Sad, Serbia
  • Stefano Guerrini                        Paris 13 University, France
  • Masahito Hasegawa                Kyoto University, Japan
  • Cynthia Kop                               Radboud University, The Netherlands
  • Pierre Lescanne                        École Normale Supérieure de Lyon, France
  • Julian Nagele                             Queen Mary University of London, UK
  • Vincent van Oostrom                University of Innsbruck, Austria

Steering Committee

  • Delia Kesner                               Université Paris 7, France
  • Femke van Raamsdonk            Vrije Universiteit, The Netherlands