Unifying Theories Of Programming: First International Symposium, Utp 2006, Walworth Castle, County Durham, Uk, February 5-7, 2006, Revised Selected Papers ... Computer Science And General Issues)

Lecture Notes in Computer Science Commenced Publication in 1973 Founding and Former Series Editors: Gerhard Goos, Juris Hartmanis, and Jan van Leeuwen Editorial Board David Hutchison Lancaster University, UK Takeo Kanade Carnegie Mellon University, Pittsburgh, PA, USA Josef Kittler University of Surrey, Guildford, UK Jon M. Kleinberg Cornell University, Ithaca, NY, USA Friedemann Mattern ETH Zurich, Switzerland John C. Mitchell Stanford University, CA, USA Moni Naor Weizmann Institute of Science, Rehovot, Israel Oscar Nierstrasz University of Bern, Switzerland C. Pandu Rangan Indian Institute of Technology, Madras, India Bernhard Steffen University of Dortmund, Germany Madhu Sudan Massachusetts Institute of Technology, MA, USA Demetri Terzopoulos University of California, Los Angeles, CA, USA Doug Tygar University of California, Berkeley, CA, USA Moshe Y. Vardi Rice University, Houston, TX, USA Gerhard Weikum Max-Planck Institute of Computer Science, Saarbruecken, Germany 4010 Steve Dunne Bill Stoddart (Eds.) Unifying Theories of Programming First International Symposium, UTP 2006 Walworth Castle, County Durham, UK February 5-7, 2006 Revised Selected Papers 13 Volume Editors Steve Dunne Bill Stoddart University of Teesside School of Computing Borough Road, Middlesbrough, TS1 3BA, UK E-mail: {s.e.dunne,w.j.stoddart}@tees.ac.uk The cover illustration represents Walworth Castle, County Durham, UK Library of Congress Control Number: 2006926663 CR Subject Classification (1998): F.1, D.3, D.1, D.2, D.4 LNCS Sublibrary: SL 1 – Theoretical Computer Science and General Issues ISSN ISBN-10 ISBN-13 0302-9743 3-540-34750-X Springer Berlin Heidelberg New York 978-3-540-34750-7 Springer Berlin Heidelberg New York This work is subject to copyright. All rights are reserved, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, re-use of illustrations, recitation, broadcasting, reproduction on microfilms or in any other way, and storage in data banks. Duplication of this publication or parts thereof is permitted only under the provisions of the German Copyright Law of September 9, 1965, in its current version, and permission for use must always be obtained from Springer. Violations are liable to prosecution under the German Copyright Law. Springer is a part of Springer Science+Business Media springer.com © Springer-Verlag Berlin Heidelberg 2006 Printed in Germany Typesetting: Camera-ready by author, data conversion by Scientific Publishing Services, Chennai, India Printed on acid-free paper SPIN: 11768173 06/3142 543210 Preface A number of formal notations and theories have now emerged and proved themselves effective as tools for the practising software engineer. Within these theories we see a number of common themes, such as abstraction, refinement, choice, termination, feasibility, concurrency and communication. The commonality of such themes opens perspectives for unifying theories, an activity which can increase our ability to use existing methods and notations, to recognise their limitations, and to extend and generalise them. Based on the pioneering work on unifying theories of programming of Tony Hoare and He Jifeng, which itself acknowledges the influence of Eric Hehner’s seminal ideas on predicative programmin