From windley@cheetah  Wed Oct 25 14:18:34 1989
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To: info-hol@clover
Subject: REWRITING WITH TRUTH
Date: Wed, 25 Oct 89 14:18:20 -0800
From: Phil Windley <windley@cheetah>


It is sometimes necessary to manipulate the assumption list and then
rewrite using it.  I have found that when these manipulations reduce some
of the assumptions to TRUTH (i.e. |- T), the rewriting fails in a
namestack overflow.  I don't think that this should happen.

Shouldn't REWRITE_TAC ignore theorems in the rewrite list that are not
equalities (including |- T)?  Is this an artifact of T being defined
through an equality?

N.B. The problem can be worked around by filtering the assumption list by
using FILTER_ASM_REWRITE_TAC, but I'd rather not have to anticipate this.

--phil--

Phil Windley                          |  windley@cheetah.ucdavis.edu
Division of Computer Science          |  ucbvax!ucdavis!cheetah!windley
College of Engineering                |  (916) 752-6452 (or 3168)
University of California, Davis       |  Davis, CA 95616




