Changes by: Xin Yu (xiny at cs.caltech.edu)
Date: 2003-02-24 21:51:45 -0800 (Mon, 24 Feb 2003)
Revision: 4122
Log message:
1. Added display forms for the terms.
2. Separate commutative semigroup/monoid and abelian group from the
grouplikeobj/group modules.
Any comment on the display forms?