Preface: Volume 50, Issue 4

Abstract

IntroductionVerification of Parameterized Systems - VEPAS 2001This part of the volume contains the Proceedings of the ICALP 2001 Satellite Workshop on Verification of Parameterized Systems (VEPAS 2001), held in the Aldemar Knossos Royal Village Hotel, Hersonissos, Crete, Greece on 13 July 2001.Previously, abstract models used in formal verification could be classified into finite-state models and infinite-state models. This distinction begins to blur as a new field emerges: “parameterized verification”. In parameterized verification the abstract models can contain parameters. Thus, they do not represent single instances of systems, but actually whole (possibly infinite) classes of instances. The goal is to show the correctness independently of the parameter and thus for the whole class. For example, one wants to show the correctness of a communication protocol for an arbitrary number n of participants or the correctness of an elevator control software for an arbitrary number n of floors. Parameterized verification is of special importance w.r.t. scalability of systems, i.e., one wants to show the correctness of a system with a certain basic structure independently of its size. While proof techniques have been used for such problems for some time, more recently also algorithmic and semi-algorithmic approaches are being developed. These often use automata theoretic models and acceleration techniques.The main topics of VEPAS 2001 were the following: •Abstract models for systems with an arbitrary number of components.•Scalability of systems and verification methods.•Abstraction methods and proof techniques in verification.•Automata theoretic models, fixpoints and acceleration methods.•Combinations of algorithms and proof techniques.VEPAS 2001 was one of the four satellite workshops of the 28th International Colloquium on Automata, Languages and Programming (ICALP 2001), held in Crete, Greece, July 8-12, 2001.The five papers in this volume were selected by the Program Committee from nine submissions received in response to a Call for Papers. The proceedings appear as Volume 50 No. 4 in the series Electronic Notes in Theoretical Computer Science (ENTCS). The volumes in the ENTCS series can be accessed at the URL http://www.elsevier.nl/locate/entcs.The program committee of VEPAS 2001 consisted of the following people: •Ahmed Bouajjani (Université Paris 7, France)•Bengt Jonsson (Uppsala University, Sweden)•Antonín Kucera (Masaryk University, Czech Republic)•Richard Mayr (chair) (Albert-Ludwigs University Freiburg, Germany)•A. Prasad Sistla (University of Illinois at Chicago, USA)We would like to thank Christos Zaroliagis (ICALP 2001 Satellite Workshops Coordinator) for his continuous support. Many thanks are due to Parosh Abdulla and Ahmed Bouajjani (Invited Speakers) and to the members of the Program Committee as well as their sub-referees for their accurate work.July 2001 Richard Mayr