Preface

TERMGRAPH 2020 took place on 5 July 2020 as a one-day satellite event of FSCD 2020. Due to the Covid-19 pandemic the event was held online. Previous editions of TERMGRAPH took place in Barcelona (2002), Rome (2004), Vienna (2006), Braga (2007), York (2009), Saarbrucken (2011), Rome (2013), Vienna (2014), Eindhoven (2016), and Oxford (2018).

Graphs, and graph transformation systems, are used in many areas within Computer Science: to represent data structures and algorithms, to define computation models, as a general modelling tool to study complex systems, etc.

Research in term and graph rewriting ranges from theoretical questions to practical implementation issues. Different research areas include: the modelling of first- and higher-order term rewriting by (acyclic or cyclic) graph rewriting, the use of graphical frameworks such as interaction nets and sharing graphs (optimal reduction), rewrite calculi for the semantics and analysis of functional programs, graph reduction implementations of programming languages, graphical calculi modelling concurrent and mobile computations, object-oriented systems, graphs as a model of biological or chemical systems, and automated reasoning and symbolic computation systems working on shared structures.

The aim of this workshop is to bring together researchers working in these different domains and to foster their interaction, to provide a forum for presenting new ideas and work in progress, and to enable newcomers to learn about current activities in this area.

Three extended abstracts were selected by the Programme Committee for presentation at TERMGRAPH 2020. In addition, the programme included invited talks by Dan Ghica and Nicolas Behr. The three regular papers in the present proceedings are significantly extended versions of their pre-proceedings version. The two papers by Dan Ghica and Nicolas Behr are invited contributions based on their invited talks. All five contributions were subjected to an additional round of reviewing by the Programme Committee.

The Programme Committee of TERMGRAPH 2020 consisted of Beniamino Accattoli, Clemens Grabmayer, David Sabel, Femke van Raamsdonk, Frédéric Prost, Makoto Hamana, Patrick Bahr (chair), Wolfram Kahl, and Zena Ariola.

I would like to thank all those who contributed to TERMGRAPH 2020, particularly the invited speakers, programme committee members, and local organisers.