
The GAP 4 package 'NQL'
=======================

Introduction
------------

This is the package 'NQL' written for GAP 4. It provides a first
construction of finitely L-presented groups and a nilpotent quotient
algorithm for L-presented groups.

The features of this package include

  - creating an L-presented group as new gap object,

  - computing nilpotent quotients of L-presented groups, and

  - epimorphisms from the L-presented group onto its
    nilpotent quotients;

  - computing the abelian invariants of an L-presented group

There is a manual in the subdirectory 'doc' written in plain TeX which
describes the functions available.

If you have found a bug or any features missing please let me know
(Ren\'e Hartung, email r.hartung [ed] tu-braunschweig.de).


Contents
--------

With this version you should have obtained the following files and
directories:

  README          this file

  init.g          the file that initializes this package

  read.g          the file that reads in the package        

  PackageInfo.g   the file for the new package loading mechanism

  doc             the manual

  gap             the GAP code


Installation
------------

Make sure that the GAP 4 packages Polycyclic and FGA are installed. It
suffices to unpack the package in the 'pkg' directory and load the
package from within gap using `LoadPackage("NQL");'.


Test-Files
----------

The NQL-package can be tested with `ReadPackage("NQL","tst/testall.gi");'.


Compiling the Manual
--------------------

To get the manual and the GAP Help System work you have to compile the
documentation of the 'NQL' package. For this purpose, change into the
'doc' directory of 'NQL' and compile the manual via 'make':

  sh> cd $GAPPATH/pkg/nql/doc
  sh> make


BugFixes/Changes/Features Added
-----------------------------

- Version 0.09: - added methods for computing (finite index) subgroups
                - AutPGrp as SuggestedOtherPackages

- Version 0.08: - minor changes due to problems with the FR-package
                - added operation `DwyerQuotient'

- Version 0.07: - added methods for approximating the Schur-multiplier
 		  of an LpGroup via its Dwyer-filtration
                - added method for approximation the outer automorphism
                  group of an LpGroup
                - bug fixed in <SmallerQuotientSystem>,
		- added method for saving a nilpotent quotient system,
		- added method for <IsomorphismLpGroup> and <AsLpGroup>,
		- added methods <NqEpimorphismNilpotentQuotient> and 
                  <NilpotentQuotient> for FpGroups (if Werner's NQ is not
                  present),
		- added a parallel version of <ExtendQuotientSystem> using
 		  Gene Cooperman's ParGap-package,

- Version 0.06: - finally accepted!

- Version 0.05: - replaced DepthVector by PositionNonZero (due to 
                  conflicts with FR).

- Version 0.04: - Included the remarks from the referee, 
		- added test files,
		- added test whether or not an LpGroup is invariant
		- name space for internal functions `NQL_*'

- Version 0.03: Renamed the function CoveringGroup due to conflicts 
                with the cohomolo package.
