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GAP Data Library "small"

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This library has the status of an accepted GAP package, communicated in January 2002 by Mike F. Newman, Canberra. It is part of the main GAP distribution.

Authors

Hans Ulrich Besche, Bettina Eick, and Eamonn O'Brien.

Description

The small groups library contains all groups of certain ``small'' orders. The groups are sorted by their orders and they are listed up to isomorphism; that is, for each of the available orders a complete and irredundant list of isomorphism type representatives of groups is given. Currently, the library contains the following groups:
  • those of order at most 2000 except 1024 (423 164 062 groups);
  • those of order 5^5 and 7^4 (92 groups);
  • those of order q^n * p where q^n divides 2^8, 3^6, 5^5 or 7^4 and p is an arbitrary prime different to q;
  • those whose order factorises into at most 3 primes.
The library also has an identification function: it returns the library number of a given group. Currently, this function is available for all orders in the library except 512 and 1536.

The library is organised in 8 layers. Each layer contains the groups of certain orders and their corresponding group identification routines. It is possible to install the first $n$ layers of the group library and the first $m$ layers of the group identification for each $1 <= m <= n <= 8$. In summary, the layers are:
  • the groups whose order factorises into at most 3 primes.
  • the remaining groups of order at most 1000 except 512 and 768.
  • the remaining groups of order 2^n * p with n < 9 and p an odd prime.
  • the groups of order 5^5 and 7^4 and the remaining groups of order q^n * p where q^n divides 3^6, 5^5 or 7^4 and p is a prime with p not equal to q.
  • the remaining groups of order at most 2000 except 1024, 1152, 1536 and 1920.
  • the groups of orders 1152 and 1920.
  • the groups of order 512.
  • the groups of order 1536.

GAP Manual section

Small Groups

Contact addresses

Hans Ulrich Besche
Institut Computational Mathematics
Universität Braunschweig
Pockelsstr. 14
38106 Braunschweig
Germany
email: hubesche@tu-bs.de

Bettina Eick
Institut Computational Mathematics
TU Braunschweig
Pockelsstr. 14
D-38106 Braunschweig
Germany
email: beick@tu-bs.de

Eamonn O'Brien
Department of Mathematics
University of Auckland
Auckland, Private Bag 92019
New Zealand
email: obrien@math.auckland.ac.nz