# Descriptional Complexity of Formal Systems

DCFS, the International Workshop on Descriptional Complexity of Formal Systems is an annual academic conference in the field of computer science.
Beginning with the 2011 edition, the proceedings of the workshop appear in the series Lecture Notes in Computer Science. Already since the very beginning, extended versions of selected papers are published as special issues of the International Journal of Foundations of Computer Science, the Journal of Automata, Languages and Combinatorics, of Theoretical Computer Science, and of Information and Computation In 2002 DCFS was the result of the merger of the workshops DCAGRS (Descriptional Complexity of Automata, Grammars and Related Structures) and FDSR (Formal Descriptions and Software Reliability). The workshop is often collocated with international conferences in related fields, such as ICALP, DLT and CIAA.

## Topics of the workshop

Typical topics include:
* various measures of descriptional complexity of automata, grammars, languages and of related systems
* trade-offs between descriptional complexity and mode of operation
* circuit complexity of Boolean functions and related measures
* succinctness of description of (finite) objects
* state complexity of finite automata
* descriptional complexity in resource-bounded or structure-bounded environments
* structural complexity
* descriptional complexity of formal systems for applications (e.g. software reliability, software and hardware testing, modelling of natural languages)
* descriptional complexity aspects of nature-motivated (bio-inspired) architectures and unconventional models of computing
* Kolmogorov–Chaitin complexity and descriptional complexity
As such, the topics of the conference overlap with those of the International Federation for Information Processing Working Group 1.2 on descriptional complexity.

## Significance

In a survey on descriptional complexity, Holzer & Kutrib (2010) state that "since more than a decade the Workshop on 'Descriptional Complexity of Formal Systems' (DCFS), [...] has contributed substantially to the development of [its] field of research." In a talk on the occasion of the 10th anniversary of the workshop, Dassow (2009) gave an overview about trends and directions in research papers presented at DCFS.

## History of the workshop

Chairs of the Steering Committee of the DCFS workshop series:
| Period | Chair |
| 1999 - 2005 | Detlef Wotschke |
| 2006 - 2017 | Giovanni Pighizzini |
| 2017 - | Martin Kutrib |
Basic information on each DCFS event, as well as on its precursors, DCAGRS and FSDR, is included in the following table.
| Event | Location | PC chairs | Proceedings | Special issue |
| 1st DCAGRS 1999 | Magdeburg, Germany | Jürgen Dassow Detlef Wotschke | | Journal of Automata, Languages and Combinatorics 5(3), 2000 |
| 2nd DCAGRS 2000 | London, Ontario, Canada | Helmut Jürgensen | | Journal of Automata, Languages and Combinatorics 6(4), 2001 |
| 3rd DCAGRS 2001 | Vienna, Austria | Jürgen Dassow Detlef Wotschke | | Journal of Automata, Languages and Combinatorics 7(4), 2002 |
| 1st FSDR 1998 | Paderborn, Germany | | | |
| 2nd FSDR 1999 | Boca Raton, Florida, USA | | | |
| 3rd FSDR 2000 | San Jose, California, USA | | | |
| 4th DCFS 2002 Archived 2016-03-03 at the Wayback Machine | London, Ontario, Canada | Jürgen Dassow Helmut Jürgensen Detlef Wotschke | | Journal of Automata, Languages and Combinatorics 9(2/3), 2004 |
| 5th DCFS 2003 | Budapest, Hungary | Erzsébet Csuhaj-Varjú Chandra Kintala Detlef Wotschke | | Theoretical Computer Science 330(2), 2005 |
| 6th DCFS 2004 | London, Ontario, Canada | Lucian Ilie Detlef Wotschke | | International Journal of Foundations of Computer Science 16(5), 2005 |
| 7th DCFS 2005 Archived 2017-11-13 at the Wayback Machine | Como, Italy | Giovanni Pighizzini Detlef Wotschke | | Journal of Automata, Languages and Combinatorics 12(1/2), 2007 |
| 8th DCFS 2006 | Las Cruces, New Mexico, USA | Hing Leung Giovanni Pighizzini | | Theoretical Computer Science 387(2), 2007 |
| 9th DCFS 2007 | High Tatras, Slovakia | Viliam Geffert Giovanni Pighizzini | | International Journal of Foundations of Computer Science 19(4), 2008 |
| 10th DCFS 2008 | Charlottetown, Canada | Cezar Câmpeanu Giovanni Pighizzini | | Theoretical Computer Science 410(35), 2009. |
| 11th DCFS 2009 | Magdeburg, Germany | Jürgen Dassow Giovanni Pighizzini | EPTCS 3 | Journal of Automata, Languages and Combinatorics, 15(1-2), 2010 |
| 12th DCFS 2010 | Saskatoon, Saskatchewan, Canada | Ian McQuillan Giovanni Pighizzini | EPTCS 31 | International Journal of Foundations of Computer Science, 23(1), 2012 |
| 13th DCFS 2011 | Giessen, Germany | Markus Holzer Martin Kutrib Giovanni Pighizzini | LNCS 6808 | Theoretical Computer Science, 449, 2012 |
| 14th DCFS 2012 | Braga, Portugal | Martin Kutrib Nelma Moreira Rogério Reis | LNCS 7386 | Journal of Automata, Languages and Combinatorics, 17(2-4), 2012 |
| 15th DCFS 2013 Archived 2016-03-05 at the Wayback Machine | London, Ontario, Canada | Helmut Jürgensen Rogério Reis | LNCS 8031 | International Journal of Foundations of Computer Science, 25(7), 2014 |
| 16th DCFS 2014 | Turku, Finland | Helmut Jürgensen Juhani Karhumäki Alexander Okhotin | LNCS 8614 | Theoretical Computer Science, 610, 2016 |
| 17th DCFS 2015 | Waterloo, Ontario, Canada | Alexander Okhotin Jeffrey O. Shallit | LNCS 9118 | Information and Computation, 259(2), 2018 |
| 18th DCFS 2016 | Bucharest, Romania | Cezar Câmpeanu Jeffrey O. Shallit | LNCS 9777 | Journal of Automata, Languages and Combinatorics, 22(1-3), 2017 |
| 19th DCFS 2017 | Milan, Italy | Cezar Câmpeanu Giovanni Pighizzini | LNCS 10316 | International Journal of Foundations of Computer Science, 30(6-7), 2019 |
| 20th DCFS 2018 | Halifax, NS, Canada | Stavros Konstantinidis Giovanni Pighizzini | LNCS 10952 | Theoretical Computer Science, 798, 2019 |
| 21st DCFS 2019 | Košice, Slovakia | Galina Jirásková Stavros Konstantinidis | LNCS 11612 | Information and Computation, to appear |
| 22nd DCFS 2020 | Vienna, Austria (cancelled) | Galina Jirásková Giovanni Pighizzini | LNCS 12442 (collected papers) | Journal of Automata, Languages and Combinatorics, in progress |