[GAP Forum] Acceptance of the NQL package
Alexander Konovalov
alexander.konovalov at gmail.com
Fri Aug 7 15:22:45 BST 2009
Dear GAP Forum,
It is my pleasure to announce the acceptance of the GAP package NQL
by René Hartung, and to thank its author for his contribution to the
GAP system.
The NQL Package defines new GAP objects to work with certain recursively
presented groups: the so-called finitely L-presented groups.
The main part of the package is a nilpotent quotient algorithm for
L-presented groups, which takes as input an L-presented group L and
a positive integer c, and computes a polycyclic presentation for the
lower central series quotient L/gamma_c(L).
The notion of an L-presentation was introduced by Laurent Bartholdi in
2003, who proved that various branch groups are finitely L-presentable
but not finitely presentable. Famous examples of finitely L-presented
groups are the Grigorchuk group, the Basilica group, the Lamplighter
group, the Brunner-Sidki-Vieira group and Fabrykowski-Gupta groups.
Further, every free group in a variety of groups satisfying finitely
many identities is finitely L-presented, for example, free Burnside-
and free n-Engel groups.
The NQL package can be downloaded from its GAP webpage:
http://www.gap-system.org/Packages/nql.html
where you can also find HTML and PDF documentation.
Best wishes,
Alexander Konovalov
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