J.UCS Special Issue on BCTCS

The six papers in this issue are based on work presented at the 15th British Colloquium for Theoretical Computer Science (BCTCS) held at the University of Keele in April 1999 and organised by John Stell. Although BCTCS has been running for a number of years, the Keele colloquium is the rst for which participants have been able to submit papers for publication giving more detailed treatments of contributions to the meeting. The papers in this issue provide a good overview of the typical areas that are covered by the meeting and it is hoped that the procedures inaugurated at BCTCS15 will be continued, particularly in view of the quality of the articles that resulted. The editors are glad to take this opportunity to extend their thanks to all those who supported the issue by deciding to submit papers for consideration. 1 The BCTCS a Brief History The rst meeting of the British Colloquium for Theoretical Computer Science was held in 1985 and hosted by the University of Leeds. This was initiated by John Tucker, primarily as a forum for theoreticians based in U.K. universities to meet and describe current research. One of the most important aims of this and the subsequent colloquia has been to o er a means by which postgraduate students can gain experience of presenting work and discussing this with established researchers. In order to encourage such participation the organisers have endeavoured to foster an informal atmosphere and have ensured that individuals who wish to present talks can be accommodated in the programme. The colloquium has been held annually, usually around Easter, following the success of the inaugural meeting at Leeds, and has been hosted by most of the British universities with strong interests in theoretical computer science. Since the 1988 colloquium at the University of Edinburgh, it has become customary to arrange a series of invited presentations in addition to the submitted contributions. As well as leading U.K. based gures, these have usually included at least one speaker from outside Britain. Over the past few years this has provided occasion for research students to bene t from the experience of gures such as, to select only a few, Les Valiant (1988,2000), Joseph Goguen (1989), Philippe Flajolet (1990), Henk Barendregt (1991), Paul Spirakis (1994), Jacobo Toran (1996) and Glynn Winskel (1999). Journal of Universal Computer Science, vol. 6, no. 4 (2000), 405-406 submitted: 28/1/00, accepted: 19/4/00, appeared: 28/4/00  Springer Pub. Co.