Changes by: Xin Yu (xiny at cs.caltech.edu)
Date: 2003-04-01 02:05:14 -0800 (Tue, 01 Apr 2003)
Revision: 4362
Log message:
- Proved "Every subgroup of a cyclic group is cyclic" with Alexei's membership for subset.
- A slight change in the definition of subStructure.