Preface Volume 42

AbstractThis volume contains the proceedings of Computing: The Australasian Theory Symposium (CATS), held at Bond University, Australia on 29-30 January 2001. CATS is the premier theoretical computer science conference in the Australasian region. It is held annually as part of Australasian Computer Science Week (ACSW). CATS 2001 is the seventh in the series.Previous CATS symposia have concentrated on topics such as complexity and computability, logics, and automata and number theory. This year the scope of the conference was broadened to also encompass formal specification and development methods, and verification tools. This change resulted in an increased number of submissions: 21 papers were submitted, of which 14 were accepted.This increase meant a greater burden on the international Programme Committee. Nevertheless, all papers were subjected to at least two, and in many cases three, formal reviews. Thanks are due to all members of the Programme Committee and their additional reviewers. In particular, Emo Welzl, Robert Stärk, Mariangiola Dezani-Ciancaglini and Rod Downey made outstanding contributions to the reviewing process.The CATS 2001 Programme Committee was as follows. 1Mariangiola Dezani-Ciancaglini (Università di Torino, Italy)2Rod Downey (Victoria University of Wellington, New Zealand)3Colin Fidge (The University of Queensland, Australia)4Lance Fortnow (NEC Research Institute, USA)5Joseph Goguen (University of California at San Diego, USA)6Andrew Martin (Oxford University, United Kingdom)7Ian Mason (University of New England, Australia)8János Pach (New York University, USA)9Igor Shparlinski (Macquarie University, Australia)10Mark Utting (University of Waikato, New Zealand)11Emo Welzl (ETH Zurich, Switzerland)In addition, the following individuals reviewed papers for CATS 2001. 1Marco Bernardo2Mario Coppo3Robbie Gates4Rob Goldblatt5Karl Lermer6Catherine McCartin7Brian Nielsen8Mehmet Orgun9Marina Ribaudo10Peter Robinson11Simona Ronchi della Rocca12Ivano Salvo13Robert Stärk14Frank Stephan15Ewan Tempero16Dominic VerityCATS 2001 is also honoured to host two exceptional invited speakers. •Prof. Mathai Joseph has a distinguished academic research record which includes significant contributions to multi-task scheduling theory and formal methods for fault-tolerant and real-time systems. Most recently, he has successfully made the challenging transition from academia to industry.•Prof. Carroll Morgan is widely known in the formal methods community for his fundamental contributions to the refinement calculus for deriving computer programs from their specifications. His many publications in the area have helped to popularise the calculus, especially his much cited textbook, Programming from Specifications.David Wolfram, Programme Chair for CATS 2000, provided considerable practical advice on organising the conference. Mike Mislove, Managing Editor of Electronic Notes in Theoretical Computer Science, once again supported publication of the CATS proceedings in that series and helped prepare this volume. Other ACSW 2001 organisers, especially Michael Oudshoorn, Gopal Gupta, Naomi Robinson, Jeanette Niehus and Marcus Randall assisted with practical problems. As part of ACSW, the CATS conference is sponsored by the Computer Science Association whom we thank for their continuing support.Colin Fidge, Guest EditorSoftware Verification Research CentreThe University of QueenslandAustrali