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Algebraic Process Calculi: the First Twenty Five Years and Beyond PA ’05 BRICS NS-05-3 Aceto & Gordon (eds.): PA ’05 Short Contributions BRICS Basic Research in Computer Science Short Contributions from the Workshop on Algebraic Process Calculi: The First Twenty Five Years and Beyond PA ’05 Bertinoro, Forl`ı, Italy, August 1–5, 2005 Luca Aceto Andrew D. Gordon (editors) BRICS Notes Series NS-05-3 ISSN 0909-3206 June 2005 Copyright c 2005, Luca Aceto & Andrew D. Gordon (editors). BRICS, Department of Computer Science University of Aarhus. All rights reserved. Reproduction of all or part of this work is permitted for educational or research use on condition that this copyright notice is included in any copy. See back inner page for a list of recent BRICS Notes Series publications. Copies may be obtained by contacting: BRICS Department of Computer Science University of Aarhus Ny Munkegade, building 540 DK–8000 Aarhus C Denmark Telephone: +45 8942 3360 Telefax: +45 8942 3255 Internet: [email protected] BRICS publications are in general accessible through the World Wide Web and anonymous FTP through these URLs: http://www.brics.dk ftp://ftp.brics.dk This document in subdirectory NS/05/3/ Short Contributions from the Workshop on Algebraic Process Calculi: The First Twenty Five Years and Beyond Bertinoro (Forl`ı), Italy, August 1–5, 2005 Luca Aceto Andrew D. Gordon ii Foreword The idea for this volume of the BRICS Notes Series arose during our email discussions of issues related to the scientific content of the workshop Algebraic Process Calculi: The First Twenty Five Years and Beyond that will take place in the beautiful setting of the University Residential Centre of Bertinoro with the kind sponsorship of BICI, BRICS and Microsoft Research. Our main aim in organizing this event is to celebrate the first twenty five years of research in the field of algebraic process calculi by reflecting on the achievements within this field, and sowing the seeds for its healthy future development by highlighting the most important open problems and future directions in the field, and stimulating international cooperation. The event in part was driven by the idea of a “CONCUR re-union” endorsed by Jos Baeten, Jan Bergstra, Tony Hoare, Robin Milner, and Jan Willem Klop. We felt that providing a slim volume to read and discuss during our summer days in Bertinoro would be a useful way of stimulating the participants at the workshop to think about their contribution at the meeting, and to offer the rest of the community who cannot be in Bertinoro a collection of interesting pieces on process calculi to read and ponder on. The committee decided from the very start that this volume should not consist of a collec- tion of long technical articles. After all, there are already plenty of standard outlets for those contributions. Rather, we decided to solicit from the participants at the workshop, and other selected members of our community, short essays on the theme of algebraic process calculi. Some ideas for papers that we proposed to potential contributors were: a reminiscence about the early days; a prospectus for future research; a statement of challenges or open problems; a history of a thread of research; a critical assessment of an idea or a project; a review of a seminal paper and its impact; or even a self-contained technical observation. The response from the colleagues we contacted was overwhelmingly positive, and beyond our most optimistic expectations. We trust that you will enjoy reading their varied and inter- esting contributions. As we did not seek scientific articles in the usual sense, the contributions are unrefereed. Our efforts in organizing this workshop, and in producing the present vol- ume, will be amply rewarded if young researchers will be enticed to work in process theory by reading this volume, by the solution of some of the open problems that are raised in it, or by the further development of work along the future directions highlighted in some of the contributions. Apart from our sponsors, we thank Elena Della Godenza (University Residential Centre of Bertinoro) for her tireless organizational and secretarial assistance at all times, and Uffe H. Engberg (BRICS) for his work in the production of this volume. Luca Aceto and Andrew D. Gordon edited this volume on behalf of the committee. iii Organising Committee • Luca Aceto, BRICS, Aalborg University, and Reykjav´ık University • Mario Bravetti, University of Bologna • Jim Davies, Oxford University • Wan Fokkink, Free University Amsterdam • Andrew D. Gordon, Microsoft Research • Joost-Pieter Katoen, RWTH Aachen University • Faron Moller, University of Wales Swansea • Steve Schneider, University of Surrey iv Contents Samson Abramsky, What are the fundamental structures of concurrency? We still don’t know!. ................................................................. 1 Luca Aceto and Wan Fokkink. The Quest for Equational Axiomatizations of Parallel Compo- sition: Status and Open Problems. .................................................... 6 Roberto Amadio, Gerard´ Boudol, Fred´ eric´ Boussinot and Ilaria Castellani. Reactive concur- rent programming revisited. .......................................................... 12 J.C.M. Baeten and J.A. Bergstra. Six Themes for Future Concurrency Research. 21 J.C.M. Baeten and M. Bravetti. A generic process algebra. .............................. 24 Christel Baier, Holger Hermanns, Joost-Pieter Katoen, Verena Wolf. Bisimulation and Simu- lation Relations for Markov Chains. ................................................... 30 Martin Berger. An Interview with Robin Milner. ........................................ 35 Jan Bergstra. ACP style process algebras: is the design rationale still valid? . 46 Marco Bernardo. Markovian Testing Equivalence vs. Markovian Bisimulation Equivalence. 52 Tommaso Bolognesi. Process algebra under the light of Wolfram’s NKS................... 56 Mario Bravetti. Stochastic and Real Time in Process Algebra: A Conceptual Overview. 60 Mario Bravetti, Holger Hermanns, Joost-Pieter Katoen. YMCA: Why Markov Chain Algebra? ................................................. 66 Mario Bravetti and Gianluigi Zavattaro. Service Oriented Computing: a new challenge for Process Algebras. ................................................................... 70 Stephen Brookes. Retracing CSP. ..................................................... 75 Maria Grazia Buscemi and Ugo Montanari. A Compositional Coalgebraic Model of a Frag- ment of Fusion Calculus. ............................................................. 81 Nadia Busi and Gianluigi Zavattaro. A Process Algebraic View of Coordination. 85 Samuele Carpineti and Cosimo Laneve. A rude contract language: XML schemas with chan- nels and capabilities. ................................................................ 90 P.J.L. Cuijpers and M.A. Reniers. Topological Aspects of Hybrid Processes (a treatment using non-standard analysis). .............................................................. 95 Rocco De Nicola. From Process Calculi to KLAIM and back. ............................ 100 Zoltan´ Esik.´ Cascade products and temporal logics on finite trees. 104 Rachele Fuzzati and Uwe Nestmann. Much Ado About Nothing? . 108 Rob van Glabbeek. On Specifying Timeouts. ........................................... 112 Andrew D. Gordon. V for Virtual. ..................................................... 114 v Clemens Grabmayer, Jan Willem Klop, and Bas Luttik. Reflections on a Geometry of Pro- cesses. ............................................................................. 118 Jan Friso Groote, Aad Mathijssen, Muck van Weerdenburg, and Yaroslav Usenko. From µCRL to mCRL2. .............................................................. 126 Jan Friso Groote, Michel A. Reniers, and Yaroslav S. Usenko. Discretization of Timed Au- tomata in Timed µCRL a la Regions and Zones. ........................................ 132 Radu Grosu and Scott A. Smolka. Monte Carlo Methods for Process Algebra. 137 Tony Hoare. Why Ever CSP? ......................................................... 141 Kohei Honda. Process Algebras in the Age of Ubiquitous Computing. 147 Kim G. Larsen. One 2 Many 2 One – Evolution of Timed Systems Modeling and Analysis. 150 Insup Lee, Anna Philippou, and Oleg Sogolsky. A Family of Resource-Bound Real-Time Process Algebras. ................................................................... 151 Gerald Luttgen¨ and Michael Mendler. When 1 Clock Is Not Enough. 155 Bas Luttik. What is algebraic in process theory? ....................................... 159 Sergio Maffeis. Process calculi and peer-to-peer Web data integration. 164 Kees Middelburg. Conditionals in Algebraic Process Calculi. ........................... 168 Dale Miller. A Proof Theoretic Approach to Operational Semantics. 172 George Milne. Modelling Dynamically Changing Hardware Structure. 176 Robin Milner. Pervasive process calculus. ............................................. 180 M.W. Mislove. On Combining Probability and Nondeterminism. 184 MohammadReza Mousavi. Towards SOS Meta-Theory for Language-Based Security. 188 Joel¨ Ouaknine and Steve Schneider. Timed CSP: A Retrospective. 192 Catuscia Palamidessi. Probabilistic and Nondeterministic Aspects of Anonymity. 196 Iain Phillips and Irek Ulidowski. Operational Semantics of Reversibility in Process Algebra. 200 Alban Ponse and Mark B. van der Zwaag. ACP and Belnap’s Logic. 204 K.V.S. Prasad. A Prospectus for a Calculus of Mobile Broadcasting Systems. 209 Corrado Priami. Process Calculi and Life Science. .....................................
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