FPLSA – The Finitely Presented Lie Super-Algebra Package

A Link to an External Lie Todd-Coxeter Program

When K is a finitely-presented Lie algebra, the GAP operation IsomorphismSCTableAlgebra can be used to make the structure of K explicit, in the form of an isomorphic algebra given by structure constants, which is much more amenable to further computations.

This GAP package installs an alternative method for this operation, which calls an external C program (fplsa version 4.0) to do the hard part of the computation. This speeds up the calculation and permits larger problems to be attempted. The external program has much additional functionality which is not used by the present version of the package.

Since the package contains an external C program, it works only under UNIX and requires a C compiler to install it.

Installing FPLSA

You have to perform the following steps to install FPLSA:

• Get and unpack the sources
• Use the configure script to adjust everything to your specific system
• Compile the C part of FPLSA

Getting and unpacking the sources

Typically fplsa will already be distributed along with your GAP distribution, in which case you can skip this step.

Otherwise, you can download the latest version of this package from its homepage, which is https://gap-packages.github.io/FPLSA/

You will end up with a file named fplsa-X.Y.tar.gz, where X.Y is a version string like 1.1.

You now change your current directory to the pkgsubdirectory of the location where you installed GAP. Now you extract the sources for the FPLSA package (replace X.Y with the actual version):

tar xf fplsa-X.Y.tar.gz

The tar utility unpacks the files and stores them into the appropriate subdirectories. FPLSA resides in the fplsa-X.Y subdirectory.

Configuring and Compiling the C part

You have to change your current working directory to the subdirectory FPLSA lives in. Starting from the pkg directory of your GAP installation, you can do this via this command (replace X.Y with the actual version):

cd fplsa-X.Y

Now you invoke the configure script by:

./configure ../..

This script produces some Makefiles which are used to compile the code. You do this by typing

make

If there were no error, then all C sources should have been compiled and a binary executable been built. If you now enter GAP, type

gap> LoadPackage( "fplsa" );

Then the new functionality should be available.

Documentation

Full information and documentation can be found in the manual, available as PDF doc/manual.pdf or as HTML doc/chap0_mj.html, or on the package homepage at

https://gap-packages.github.io/FPLSA/

Bug reports and feature requests

Please submit bug reports and feature requests via our GitHub issue tracker:

https://github.com/gap-packages/FPLSA/issues

License

fplsa is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

For details see the file LICENSE.

Authors

The FPLSA program was written by V Gerdt and V Kornyak, both of the:

Laboratory of Computing Techniques and Automation, Joint Institute for Nuclear Research, Dubna, Moscow Region 141980, Russia. Email: gerdt@jinr.ru and vkornyak@gmail.com