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From the Preface of GAP 4.B.1[The preface started with a copy of the preface for GAP 3.4.3 as a reference for the previous state.] Preface for the first beta release of GAP 4The transition from GAP 3.4 which got its presumably last update 3.4.4 in April this year to this present first beta release GAP 4.B.1 of GAP 4 marks a major step in the system design of GAP, similar in importance to the step from GAP 2.4 to GAP 3.1 in April 1992 on which I comment in my preface to GAP 3.4 of June 1994. However in contrast to the situation in 1992 we hope that the changes will be much less bothering to the majority of the GAP users this time. Let me first talk about some reasons and background for developing GAP 4 and then briefly sketch what remains and what changes. The planning of GAP 4 started already at the time of the release of GAP 3.4 (Summer 1994) and its development has been a major reason for the fact that since then only updates (up to GAP 3.4.4) but no new releases of GAP 3 have come out. Also a number of new algorithms have been implemented in Aachen anticipating GAP 4 and hence have not become generally available yet. There were three major reasons for the development of GAP 4:
So regarding system aspects let's briefly sketch: What is left unchanged?
What has changed?
What is new?
Then to the mathematical functionality provided by GAP 4 in comparison to GAP 3:
The other main deficiency is that there is not yet a complete manual for GAP 4. It is intended to provide eventually at least four books as parts of the manual. The first and second are intended for people who want to use GAP "as is". Books 3 and 4 on the other hand are meant for people who want to extend GAP 4 by introducing new structures. Books 1 and 3 are tutorials for the respective purpose while Books 2 and 4 are the corresponding reference manuals. Of these four books a good deal of Books 1 and 3, i.e. the tutorial parts, are provided with this release, while there are only rudimentary parts of books 2 and 4 available. For people already familiar with GAP 3 the chapter "Migrating to GAP 4" in the first book may be particularly helpful. There have been (weekly changing) alpha test versions of GAP 4 since December 1996, and a number of specially experienced GAP users in addition to the GAP teams at Aachen and St. Andrews have used these and provided helpful criticism and suggestions. It is envisaged that there will be new beta releases from now on about every couple of months until an official version GAP 4.1 can be released next year. It is hoped that these further beta releases will gradually provide the missing parts mentioned above as well as further enhancements. However, since the date of the official handover of GAP from Aachen to St. Andrews has now been fixed to be July 21, 1997, this further development will happen under the responsibility of St. Andrews. It remains to me to thank all those who have done the huge amount of work that was needed to bring GAP 4 on its way. Many basic ideas for the new concepts as well as most of the new kernel implementation are still due to Martin Schönert before and even in parts after he left Lehrstuhl D fuer Mathematik. However together with him while he was still working here and continuing after he left, Thomas Breuer and Frank Celler have in long discussions found the way to the concepts and done crucial parts of the new implementations. Many others have worked adapting and rewriting the library, of whom I want to mention in particular Bettina Eick, Alexander Hulpke and Heiko Theissen from the Aachen team but also acknowledge the help lended already for some time from St. Andrews, in particular by Steve Linton. To these and all others, whom I did not mention explicitly, I want to express my thanks for a yearlong cooperation in a spirit of enthusiasm, dedication and perseverance. I wish the team at St. Andrews a successful continuation of the development and maintenance of GAP in that same spirit and all users fun and success in using GAP. Aachen, July 18, 1997 Joachim Neubüser |