Changes by: Brian Emre Aydemir (baydemir at cis.upenn.edu)
Date: 2002-08-12 23:01:11 -0700 (Mon, 12 Aug 2002)
Revision: 3798
Log message:
This finishes my pass at typing rules for tyUnion, tyApply, and union_values.
In the process, I've implemented some simple operators for getting the length
of a list, performing type application, and testing set equality and subset.
I've also done other minor things, like cleaning up some display forms.