                            Version 1.0

1. J. Thayer, Wed Jun 30 10:24:28 EDT 1993

   Added 

   (def-theorem image-of-a-finite-set-is-finite
     "forall(s:sets[ind_1],f:[ind_1,ind_2],
        f_indic_q{s} implies f_card{image{f,s}}<=f_card{s})"

2. W. Farmer, Thu Jul  1 13:15:01 EDT 1993

   In the definition of find-first-encompassing-trans-in-list in
translation-match.t, the line

   (subset-with-equal? fixed-theories (translation-fixed-theories trans))

was changed to 

   (every?
    (lambda (th1)
      (any?
       (lambda (th2) (sub-theory? th1 th2))
       (translation-fixed-theories trans)))
    fixed-theories)


3. J. Guttman, Thu Jun 17 15:51 EDT 1993

   In the file THEORIES/reals/reals-supplements.t 

   Added (usages d-r-convergence) in

(def-theorem floor-definedness
  "forall(x:rr, #(floor(x)))"
  (usages d-r-convergence)

N.B. This notice of change was added "posthumously", after it produced
a change in the behavior of a proof, detected by the IMPS test. This
explains the following change:


4. J. Thayer, Fri Jul  2 12:02:41 EDT 1993

   The proof of 

(def-theorem division-with-remainder
  "forall(a,c:rr,
     0<a
      implies 
     a divides c-(c mod a) and 0<=c mod a and c mod a<a)"


has been modified slightly because of the change resulting from adding
a d-r-convergence usage to floor-definedness.


5. W. Farmer, Thu Jul  8 14:54:04 EDT 1993

   The procedure SAME-TRANSLATION-ALISTS? is now called
TRANSLATION-EXTENDS-ALISTS? and its body has been modified.

6. W. Farmer, Mon Jul 19 14:33:43 EDT 1993

   A subprocedure MAKE-DISTINCT-CONSTANT-OBLIGATIONS was added to the
procedure MAKE-TRANSLATION-OBLIGATIONS.


7. J. Thayer, Fri Jul 16 12:38    EDT 1993

   This is a posthumous documentation. THEORY-UNION, EXTEND-THEORY
were modified to accurately reflect the distinct-constants component
of a theory (previously regarded as a josh-oddity). For instance,
prior to the change, (THEORY-UNION TH) would return a new-theory
identical in most respects to TH but with trivial distinct-constants
info.


8. W. Farmer, Tue Jul 20 09:02    EDT 1993

   This is a posthumous documentation (actually added by jt
prehumously). BUILD-THEORY was modified for reasons similar to those of
THEORY-UNION and EXTEND-THEORY.


9. J. Thayer, Thu Jul 22 10:34:21 EDT 1993

   The procedure TRANSLATION-EXTENDS-ALISTS? was modified to correct a
bug detected by the IMPS test. (memq? pair ...) was changed to (mem?
equal? pair ... ) in 4 places. The remaining 2 memq's are justified
since sorts are uniquely instantiated.

10. J. Thayer, Thu Jul 22 14:29:59 EDT 1993
   
   Yet another change to TRANSLATION-EXTENDS-ALISTS? to correct
another bug. The two forms (every? ...) executed in succession should
have been enclosed in an AND form. 

11. W. Farmer, Wed Aug 11 15:25:10 EDT 1993

   All occurrences of "Imps" have been changed to "IMPS" (except for
comments in the theory files).

12. W. Farmer, Wed Sep  8 15:58:45 EDT 1993

   Warning messages were added to the procedures REMOVE-SORT-PAIRS and
REMOVE-CONSTANT-PAIRS in the file TRANSLATION.T.

13. J. Thayer, Fri Oct 15 15:46:09 EDT 1993

   The predicate TRIVIAL-TRANSLATION? in $IMPS/theory-mechanism/theory-ensembles.t
was changed in a way which makes it more restrictive, that is, true less often.

(define (trivial-translation? translation)
  (and (sub-theory? (translation-source-theory  translation)
		    (translation-target-theory  translation))
       (every? (lambda (x) (eq? (car x) (cdr x)))
	       (append (translation-constant-alist translation)
		       (translation-sort-alist translation)))))


Thus if a translation between two theories T_1, T_2 is trivial, then
T_1 is not a sub-theory of T_2. Soundness was not an issue in the
change. The motivation for the change was the canonical translation from
     
             METRIC-SPACES --> ULTRAMETRIC-SPACES 

documented in the theory library. 

14. J. Thayer, W. Farmer, Mon Nov 22 14:32:00 EST 1993

TRANSPORT-THEOREMS-BY-USAGE was changed to avoid the problem of
walking through the theorems of a theory while the set of theorems in
that theory changes. This apparently can lead to serious problems with
VERY, VERY bizarre consequences.

15. W. Farmer, Mon Nov 22 15:05:22 EST 1993

TRANSPORT-THEORY-AUX in the file THEORY-TRANSPORTATION.T was modified
to ensure that distinct constants are transported to distinct
constants.

16. W. Farmer, Mon Nov 22 15:05:22 EST 1993

TRANSPORT-THEOREM in the file TRANSPORTATIONS.T will no longer
transport a theorem of a fixed theory of the translation.

17. J. Thayer, Tue Nov 23 28:45 EST 1993

TRANSPORT-THEOREM was implemented in such a way that a non-expression
might be returned in case theorem was a translation fixed
theorem. Many calls expect a theorem.

18. J. Thayer, Tue Nov 23 28:45 EST 1993 

TRANSLATION-FIXED-THEOREM? was changed to

(define (TRANSLATION-FIXED-THEOREM? translation formula)
  (every?
   (lambda (th)
     (and (contains-expression? (theory-language th) formula)
	  (element-of-set? formula (theory-theorems th))))
   (translation-fixed-theories translation)))

It had been implemented with a map instead of every?
