I have installed ghc-5.02.3 and ghc-cvs-6-4-branch-June-15 on the same Linux machine, ported DoCon to 6-4-branch, and compared DoCon-2.06 - ghc-5.02.3 to DoCon-2.09 - ghc-cvs-6-4-branch-June-15 on computer algebra (the CA algorithms are the same). 1. They work correct. 2. The performance and memory eagerness difference is within about 5 %. ----------------- Serge Mechveliani mechvel@botik.ru