Changes by: Xin Yu (xiny at cs.caltech.edu)
Date: 2004-01-21 00:42:51 -0800 (Wed, 21 Jan 2004)
Revision: 5267
Log message:

      Re-formalized the theorem "The set of units forms a group under multiplication."
      

Changes	Path
+37 -50	metaprl/theories/itt/itt_unitring.ml
+3259 -2925	metaprl/theories/itt/itt_unitring.prla