Changes by: Jason Hickey (jyh at cs.caltech.edu)
Date: 1998-08-10 17:44:46 -0700 (Mon, 10 Aug 1998)
Revision: 2437
Log message:

      Red_black_set.union inserts the smaller tree into the larger,
      which is a little faster than flattening the trees.
      

Changes	Path
+60 -45	metaprl/mllib/red_black_set.ml
+7 -16	metaprl/theories/tactic/thread_refiner_tree.ml