Dear Eike, You are welcome to my matrix inverter. It compiles on GPC, and is simple to use. The inverter uses a cut-down version of Gausse-Jordan elimination. I have not yet implemented the routine with GPC's schemata types. When I do, it will be much neater. Until then, it uses pointers. If you are interested, let me know and I'll e-mail it to you directly. Yours, Kevan Hashemi, Brandeis University Physics Department.