Changes by: Jason Hickey (jyh at cs.caltech.edu)
Date: 2006-01-04 08:30:00 -0800 (Wed, 04 Jan 2006)
Revision: 8396
Log message:

      Changed the proof witness code in Itt_hoas_sequent_proof from
      unification-based to naming-based.
      
      Added more forward reasoning.  We have most of the facts, but
      we need a few more about mk_bterm, mainly that if a mk_bterm
      is well-formed, so are its subterms.  The theorems in
      Itt_hoas_bterm_wf are currently unproved.