Changes by: Aleksey Nogin (nogin at cs.caltech.edu)
Date: 2006-03-13 15:33:59 -0800 (Mon, 13 Mar 2006)
Revision: 8884
Log message:
- Changed the SimpleStep definition to use ProofCheck and the ValidStep
definition to use SimpleStep.
- Proved stronger (dependent) elimination rules for the SimpleStep.