## LiE

### A Computer algebra package for Lie group computations

LiE is a computer algebra system that is specialised in computations
involving (reductive) Lie groups and their representations. It is publically
available for free in source code. For a description of its characteristics,
we refer to the following sources of information.
### Version 2.2.2

The current version of LiE is 2.2.2, which is more or
less unchanged since about the year 2000. Minor bugfixes do get applied now
and then.
### The LiE manual

As indicated above, the manual is included in electronic form in the
distrubution. As a convenience for those without TeX installed, here is
a PDF version of the manual. A paper
version has also been published; although it is no longer in print, it may
referred to as follows
M. A. A. van Leeuwen, A. M. Cohen and B. Lisser,
"LiE, A Package for Lie Group Computations",
Computer Algebra Nederland, Amsterdam, ISBN 90-74116-02-7, 1992

### Obtaining LiE

Since July 1996, LiE is publically available for free. There have been
questions about what this means exactly, notably whether it can be
redistributed by thrid parties, and under what licence. The answer is that the
institute CWI at which LiE was developed (and therefore holds the original
copyright) has given the developers permission to do whatever they want with
the source code, and that the project leader Arjeh Cohen has decided that LiE can be
distributed under the GNU Lesser General Public
Licence. The current distribution does not contain any of the blurb
necessary to make this clear from the distribution itself; feel free to add
this if you want to distribute.
There are various versions of the software you may obtain:

If you want to try out some computations with LiE without having to
install it, you can invoke LiE through the WWW, by simply filling in a
form, and the result will be displayed.

If you want to compile and run the program, but need no documentation of the
source files, you can fetch the tarfile for a compile
only version.

You can also get a much more documented version of the source files,
which use the CWEBx software documentation system. To use this
version you need to download and compile the
CWEBx system in
addition to the
documented sources for
LiE.

Detailed instruction of how to install each of these versions can be
found in the README files contained in the individual tarfiles. Currently,
the Makefiles use the functionality of GNU make.

#### LiE on Macintosh OS X

*If you want to install
LiE on Mac OS X, please read this
note*.