CoReLG is a GAP4 package. Its main objective is to provide functionality for computing with real (semi-)simple Lie algebras.
To install the package CoReLG move the file corelg-XX.tar.gz
(or any other archive containing it) into the pkg directory.
Usually this will be the pkg subdirectory in your GAP4 installation.
However, it is also possible to have a pkg subdirectory in a
different place, see the section Installing GAP Packages of the
GAP4 reference manual for more information.
Then simply unpack corelg-XX.tar.gz and your installation is
complete.
In GAP issue
gap> LoadPackage( "corelg" );
The manual of CoReLG is contained in the doc directory. The different
versions of the manual (pdf, dvi, html) can be compiled by doing
gap> ReadPackage("corelg", "makedoc.g");