Published: 19th July 2025
DOI: 10.4204/EPTCS.422
ISSN: 2075-2180

EPTCS 422

Proceedings of the 15th International Workshop on
Non-Classical Models of Automata and Applications
Loughborough University, July 21-22, 2025

Edited by: Nelma Moreira and Luca Prigioniero
Preface
Nelma Moreira and Luca Prigioniero
Idefix-Closed Languages and Their Application in Contextual Grammars
Marvin Ködding and Bianca Truthe		1
On a Generalization of the Christoffel Tree: Epichristoffel Trees
Abhishek Krishnamoorthy, Robinson Thamburaj and Durairaj Gnanaraj Thomas		15
Input-Driven Pushdown Automata with Translucent Input Letters
Martin Kutrib, Andreas Malcher and Matthias Wendlandt		29
Orchestration of Music by Grammar Systems
Jozef Makiš, Alexander Meduna and Zbyněk Křivka		45
On Repetitive Finite Automata with Translucent Words
František Mráz and Friedrich Otto		59
A Myhill-Nerode Type Characterization of 2detLIN Languages
Benedek Nagy		73
On some Classes of Reversible 2-head Automata
Benedek Nagy and Walaa Yasin		89

Preface

The 15th International Workshop on Non-Classical Models of Automata and Applications (NCMA 2025) was held in Loughborough, UK, on July 21 and 22, 2025, organized by the Department of Computer Science at Loughborough University and co-located with the 26th International Conference on Descriptional Complexity of Formal Systems (DCFS 2025, 22-24 July).

The NCMA workshop series was established in 2009 as an annual event for researchers working on non-classical and classical models of automata, grammars or related devices. Such models are investigated both as theoretical models and as formal models for applications from various points of view. The goal of the NCMA workshop series is to exchange and develop novel ideas in order to gain deeper and interdisciplinary coverage of this particular area that may foster new insights and substantial progress.

The previous NCMA workshops took place in Wrocław, Poland (2009), Jena, Germany (2010), Milano, Italy (2011), Fribourg, Switzerland (2012), Umeå, Sweden (2013), Kassel, Germany (2014), Porto, Portugal (2015), Debrecen, Hungary (2016), Prague, Czech Republic (2017), Košice, Slovakia (2018), Valencia, Spain (2019). Due to the Covid-19 pandemic there was no NCMA workshop in 2020 and 2021. After that, the series continued in Debrecen, Hungary (2022), Famagusta, North Cyprus (2023), and Göttingen, Germany (2024).

The invited lectures at NCMA 2025 were the following:

The 7 regular contributions were selected out of 13 submissions by a total of 26 authors from 9 different countries by the following members of the Program Committee: The following additional reviewers helped in the evaluation process: In addition to the invited presentations and the regular contributions, NCMA 2025 featured 4 informal presentations to emphasize its workshop character.

A special issue of RAIRO - Theoretical Informatics and Applications containing extended versions of selected contributions to NCMA 2025 will also be edited after the workshop. The extended papers will undergo the standard refereeing process of the journal.

We are grateful to the two invited speakers, all authors who submitted a paper to NCMA 2025, the members of the Program Committee, and their sub-reviewers who helped evaluating the submissions. We are deeply indebted to Robert Mercaş from the Department of Computer Science of Loughborough University for his outstanding efforts in the local organization of the workshop. We also greatly appreciated the financial support of the Center of Mathematics of the University of Porto (CMUP).

July 2025
Nelma Moreira and Luca Prigioniero