Preface Volume 78

AbstractComputing: the Australasian Theory Symposium (CATS) is the premier theoretical computer science conference in Australasia, and originated as a meeting organised by Barry Jay in December, 1994 in Sydney. Since then, it has become an integral part of the series of meetings that comprise the Australasian Computer Science Week (ACSW), and hence previous CATS meetings have been held in Melbourne (1996), Sydney (1997), Perth (1998), Auckland (1999), Canberra (2000), the Gold Coast (2001) and Melbourne (2002).Following the pattern set at the 2000 meeting in Canberra, it is very pleasing to see the proceedings of this conference published as volume78 of Electronic Notes in Theoretical Computer Science. This ensures rapid dissemination of results, as well as simplifying conference organisation and significantly reducing costs.A total of 31 papers were submitted, of which 17 were selected for publication, after review by at least 2 (and usually 3) referees. The two invited speakers, Arun Sharma and George Havas, are both resident in Australia, but the Programme Committee felt that both were of such elevated international standing that this really counts as two international speakers.Conferences such as CATS are always the result of the efforts of a number of people. Accordingly, my thanks go to all who submitted papers, succesfully or otherwise, the additional referees for their efforts in reviewing papers, Michael Mislove (joint Managing Editor of ENTCS) for his advice and producing the relevant macros, John Roddick and the local organising committee for ACSW, Michael Oudshoorn, the ACSW Programme Chair, and finally the hard-working Programme Committee members.Programme Committee •Michael Atkinson, Otago University, Dunedin, New Zealand.•John Crossley, Monash University, Melbourne, Australia.•XiaoTie Deng, City University of Hong Kong.•Mike Fellows, Newcastle University, Australia.•Colin Fidge, University of Queensland, Brisbane, Australia.•James Harland (Chair), RMIT University, Melbourne, Australia.•Matthew Hennessy, University of Sussex, Brighton, UK•Barry Jay, University of Technology, Sydney, Australia.•Mike Johnson, Macquarie University, Sydney, Australia.•Xuemin Lin, University of New South Wales, Sydney, Australia.•David WolframAdditional RefereesJianer ChenShirley H.C. CheungRobert ColombMichael HouleHans HuttelSleksander IgnjatovicEd KazmierczakJianping LiWiafa LiangSeng LokeFaron MollerChung Keung PoonDavid PymPeter RobinsonDon SannellaHarald SondergaardArcot SowmyaFeng TianHagen VolzerLuke WildmanMichael WinikoffDavid WoodLimsoon WongDavid WrightJian XuJingling XueQing Zhan