Changes by: Brian Emre Aydemir (baydemir at cis.upenn.edu)
Date: 2002-08-12 15:22:53 -0700 (Mon, 12 Aug 2002)
Revision: 3793
Log message:
This is my pass at typing rules for union definitions. Had to add a length
operator to the list implementation. Other miscellaneous changes include some
minor display form changes.