Dear GAP Forum

Two questions have been raised in recent months, one in the forum, about
coupling GAP and other computer algebra systems (specifically Maple and
Mathematica). The answer, which is the same for both, and describes the
general situation for coupling GAP to other general purpose software, may be
of wider interest:

There is no software that one could regard as "finished work" for linking GAP
to either of these two systems. There are some very old programs that were
once contributed for converting between GAP3 and Mathematica formats, but I
don't know how much they did.

If you want to develop your own connections between the systems, I can suggest
some starting points:

1. As of GAP 4.2, GAP has capabilities to run other programs in the background
and communicate with them through their command-line interfaces. (see the "New
Features for Developers" manual of this release).

2. If you want to run GAP in the background, I can advise you on a number of
special command-line options which make this easier. They were developed for
xgap and may not do exactly what you want, but they should help.

3. There is a package in development, of which you should be able to get test
versions easily enough, which allows GAP to read and write in the OpenMath
format, at least where OpenMath representations of the objects in question
exist. Both OpenMath and the package should be easily extended to handle the
objects you need. There also exist experimental OpenMath interfaces for Maple
or Mathematica, and so, subject to the usual caveats of using experimental
software, you may be able to build communication using those.
http://www.openmath.org is probably the best general starting point for
information about OpenMath.

Steve Linton