Preface
About &GAP; manual

Welcome to &GAP;. This is one of three manuals documenting the core part of &GAP;, the other being the &GAP; Tutorial (see ). and the document called &GAP; - Changes from Earlier Versions (see ).

This preface serves not only to introduce The &GAP; Reference Manual, but also as an introduction to the whole system.

&GAP; stands for Groups, Algorithms and Programming. The name was chosen to reflect the aim of the system, which is introduced in this reference manual. Since that choice, the system has become somewhat broader, and you will also find information about algorithms and programming for other algebraic structures, such as semigroups and algebras.

This manual, the &GAP; reference manual contains the official definitions of &GAP; functions. It should contain all the information needed to use &GAP;, and is not intended to be read cover-to-cover.

To get started a new user may first look at parts of the &GAP; Tutorial (see ).

A lot of the functionality of the system and a number of contributed extensions are provided as &GAP; packages which are developed independently of the core part of &GAP; and can be loaded into a &GAP; session. Each package comes with a its own manual which is also available through the &GAP; help system.

This manual is divided into chapters, sections and subsections. Chapter describes the help system, which provides access to all the manuals from a running &GAP; session. Chapter gives technical advice for running &GAP;. Chapter introduces the &GAP; language, and the next chapters deal with the environment provided by &GAP; for the user. These are followed by the main bulk of chapters which are devoted to the various mathematical structures that &GAP; can handle.

Subsequent sections of this preface explain the structure of the system and provide copyright and licensing information.

The &GAP; System
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Authors and Maintainers
&GAP; is the work of very many people, many of whom still maintain parts of the system. A complete list of authors, and an approximation to the current list of maintainers can be found on the &GAP; World Wide Web site at http://www.gap-system.org/Contacts/People/authors.html and http://www.gap-system.org/Contacts/People/modules.html.

All &GAP; packages have their own authors and maintainers. It should however be noted that some packages provide interfaces between &GAP; and an external program, a copy of which is included for convenience, and that, in these cases, we do not claim that the package authors or maintainers wrote, or maintain, this external program. Similarly, the system and some packages include large data libraries that may have been computed by many people. We try to make clear in each case what credit is attributable to whom.

We have, for some time, operated a refereeing system for contributed packages, both to ensure the quality of the software we distribute, and to provide recognition for the authors. We now consider this to be a refereeing system for modules, and we would note, in particular that, although it does not use the standard package interface, the library of small groups has been refereed and accepted on exactly the same basis as the accepted packages.

We also include with this distribution a number of packages which have not (yet) gone through our refereeing process. Some may be accepted in the future, in other cases the authors have chosen not to submit them. More information can be found on our World Wide Web site (see Section ).

Acknowledgements

Very many people have worked on, and contributed to, &GAP; over the years since its inception. On our Web site you will find the prefaces to the previous releases, each of which acknowledges people who have made special contributions to that release. Even so, it is appropriate to mention here Joachim Neubüser whose vision of a free, open and extensible system for computational algebra inspired &GAP; in the first place, and Martin Schönert, who was the technical architect of &GAP; 3 and &GAP; 4.

Copyright and License
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Further Information about &GAP;
web sites
email addresses
support
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