This file is indexed.

/usr/share/hol88-2.02.19940316/lisp/f-inst.l is in hol88-source 2.02.19940316-28.

This file is owned by root:root, with mode 0o644.

The actual contents of the file can be viewed below.

  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;;                             HOL 88 Version 2.0                          ;;;
;;;                                                                         ;;;
;;;   FILE NAME:        f-inst.l                                            ;;;
;;;                                                                         ;;;
;;;   DESCRIPTION:      Object language type instantiation                  ;;;
;;;                                                                         ;;;
;;;   USES FILES:       f-franz.l (or f-cl.l), f-constants.l, f-macro.l,    ;;;
;;;                     f-ol-rec.l                                          ;;;
;;;                                                                         ;;;
;;;                     University of Cambridge                             ;;;
;;;                     Hardware Verification Group                         ;;;
;;;                     Computer Laboratory                                 ;;;
;;;                     New Museums Site                                    ;;;
;;;                     Pembroke Street                                     ;;;
;;;                     Cambridge  CB2 3QG                                  ;;;
;;;                     England                                             ;;;
;;;                                                                         ;;;
;;;   COPYRIGHT:        University of Edinburgh                             ;;;
;;;   COPYRIGHT:        University of Cambridge                             ;;;
;;;   COPYRIGHT:        INRIA                                               ;;;
;;;                                                                         ;;;
;;;   REVISION HISTORY: Original code: ol3 (lisp 1.6) part of Edinburgh LCF ;;;
;;;                     by M. Gordon, R. Milner and C. Wadsworth   (1978)   ;;;
;;;                     Transported by G. Huet in Maclisp on Multics, Fall  ;;;
;;;                     1981                                                ;;;
;;; Hol version 2.02:   Bug in INST_TYPE fixed :        [MJCG 25.01.94]     ;;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

;;; Sharing relationships in types must be detected -- dumb algorithms that
;;; expand type DAGs into trees will consume exponential time and space!
;;; This particularly holds for algorithms that traverse all types of a term,
;;; for note the duplication of types in combinations:
;;;             ((F : ty1 -> ty2)  (X : ty1))  : ty2

;;; The instantiation of terms and formulas is now implemented in Lisp,
;;; as the ML versions were exponential.

(eval-when (compile)
   #+franz (include "lisp/f-franz")
   (include "lisp/f-constants")
   (include "lisp/f-macro")
   (include "lisp/f-ol-rec")
   (special %clash-danger-vars))


#+franz
(declare
   (localf tyvars-type instin-type instin-var rename-var forget-var
           typel-in-tm strip-primes-aux strip-primes))


;;; *********************************************


(dml |type_in_type| 2 ml-type_in_type ((|type| |#| |type|) -> |bool|))
(dml |type_in| 2 ml-type_in_term ((|type| |#| |term|) -> |bool|))

;;; No formulas in HOL: paired_type_in_form deleted	[TFM 90.04.19]
;;; (dml |paired_type_in_form| 2 ml-type_in_form ((|type| |#| |form|) -> |bool|))


(defun ml-type_in_type (%ty ty)
   (let ((%oldtys nil)) (type-in-type ty)))


;;; does %ty occur anywhere inside ty?
;;; record compound types already seen to avoid re-traversal
(defun type-in-type (ty)
   (cond ((memq ty %oldtys) nil)
      ((equal ty %ty) t)
      ((not (is-vartype ty))
         (prog1 (exists 'type-in-type (cdr (ml-dest_type ty)))
            (push ty %oldtys)))
      ))  ;type-in-type


;;; No formulas in HOL: deleted	[TFM 90.04.19]
;;;(defun ml-type_in_form (%ty ob)
;;;   (let ((%oldtys nil)) (type-in-fm ob)))


(defun ml-type_in_term (%ty ob)
   (let ((%oldtys nil)) (type-in-tm ob)))


;;; does %ty appear in the formula?
(defun type-in-fm (fm)
   (case (form-class fm)
      ((conj disj imp) ; iff deleted [TFM 90.01.20]
         (or (type-in-fm (get-left-form fm)) (type-in-fm (get-right-form fm))))
      ((forall exists)
         (or (type-in-tm (get-quant-var fm)) (type-in-fm (get-quant-body fm))))
      (pred (type-in-tm (get-pred-arg fm)))
      (t (lcferror (cons fm '|type-in-fm|))))
   )    ; type-in-fm


;;; does %ty appear in the term?
(defun type-in-tm (tm)
   (case (term-class tm)
      ((var const) (type-in-type (get-type tm)))
      (abs (or (type-in-tm (get-abs-var tm)) (type-in-tm (get-abs-body tm))))
      (comb (or (type-in-tm (get-rator tm)) (type-in-tm (get-rand tm))))
      (t (lcferror '|type-in-tm|)))
   )    ; type-in-tm


;;; *********************************************

(dml |type_tyvars| 1 ml-type-tyvars (|type| -> (|type| |list|)))


;;; term_tyvars renamed to be tyvars [TFM 90.06.04]
;;; (dml |term_tyvars| 1 ml-term_tyvars (|term| -> (|type| |list|)))

(dml |tyvars| 1 ml-term_tyvars (|term| -> (|type| |list|)))

;;; Deleted: formulas not used in HOL  [TFM 90.06.27]
;;; (dml |form_tyvars| 1 ml-form_tyvars (|form| -> (|type| |list|)))


(defun ml-type-tyvars  (ty)
   (let ((%tyvl nil) (%oldtys nil))
      (tyvars-type ty)
      (nreverse %tyvl)))          ; ml-type-tyvars




;;; find all type variables in a type
;;;
;;; [DES] 17feb92 member-equal for memq; again exponentiality.
;;; Looks as if my big tuples have gone over the limit where things
;;; start showing up. Found another problem as equivalent types
;;; are not necessarily "eql". This shows itself up in
;;; tyvars-type. Basically %oldtys was getting over 4000 things
;;; stuck on it. When using member-equal only 170 were there 
;;; (i.e. 3800-odd members were equiavalent types with a
;;; different top level cons cell).
;;;
;;; (defun tyvars-type (ty)
;;;   (cond ((memq ty %oldtys))
;;;      ((is-vartype ty) (setq %tyvl (inq ty %tyvl)))
;;;      (t (mapc #'tyvars-type (cdr (ml-dest_type ty)))
;;;         (push ty %oldtys))    
;;;      ))   ; tyvars

(defun tyvars-type (ty)
   (cond ((member-equal ty %oldtys))
      ((is-vartype ty) (setq %tyvl (inq ty %tyvl)))
      (t (mapc #'tyvars-type (cdr (ml-dest_type ty)))
         (push ty %oldtys))
      ))   ; tyvars

;;; Deleted: formulas not used in HOL  [TFM 90.06.27]
;;; (defun ml-form_tyvars(ob)
;;;   (let ((%tyvl nil) (%oldtys nil))
;;;      (tyvars-fm ob)
;;;      (nreverse %tyvl)))


(defun ml-term_tyvars(ob)
   (let ((%tyvl nil) (%oldtys nil))
      (tyvars-tm ob)
      (nreverse %tyvl)))


;;; find all type variables in a formula
(defun tyvars-fm (fm)
   (case (form-class fm)
	 ((conj disj imp) ; iff deleted [TFM 90.01.20]
         (tyvars-fm (get-left-form fm)) (tyvars-fm (get-right-form fm)))
      ((forall exists)
         (tyvars-tm (get-quant-var fm)) (tyvars-fm (get-quant-body fm)))
      (pred (tyvars-tm (get-pred-arg fm)))
      (t (lcferror (cons fm '|tyvars-fm|))))
   )                                             ; tyvars-fm


;;; find all type variables in a term
(defun tyvars-tm (tm)
   (case (term-class tm)
      ((var const) (tyvars-type (get-type tm)))
      (abs (tyvars-tm (get-abs-var tm)) (tyvars-tm (get-abs-body tm)))
      (comb (tyvars-tm (get-rator tm)) (tyvars-tm (get-rand tm)))
      (t (lcferror '|tyvars-tm|)))
   )    ; tyvars-tm


;;; *********************************************

;;; type instantiation

;;; Renames variables to ensure that no distinct variables become identical
;;; after instantiation -- makes variants of all (and ONLY) those
;;; variables whose types change and whose names match.
;;; The first argument of inst_term and inst_form is
;;; a list of variables whose names must not be used.
;;; This handles free variables in the assumption list for the rule INST_TYPE.

;;; Original code does not detect capture of free variables when a type
;;; instantiation causes a variable to become identical to a lambda-bound
;;; variable whose scope it is in. This is fixed by a patch at the end
;;; of the file and in the ML code for INST_TYPE (MJCG 15/10/1989). 
;;; Problem detected by Roger Jones' group at ICL Defence Systems.


(dml |inst_type| 2 ml-inst_type
   ((((|type| |#| |type|) |list|) |#| |type|) -> |type|))

(dml |inst| 3 ml-inst_term
   (((|term| |list|) |#| (((|type| |#| |type|) |list|) |#| |term|)) -> |term|))

;;; No formulas in HOL: paired_inst_form deleted	[TFM 90.04.19]
;;;(dml |paired_inst_form| 3 ml-inst_form
;;;   (((|term| |list|) |#| (((|type| |#| |type|) |list|) |#| |form|)) -> |form|))


(defun ml-inst_type (%insttyl ty)
   (if %insttyl (instin-type ty) ty))  ;ml-instintype


;;; No formulas in HOL: ml-inst_form deleted	[TFM 90.04.19]
;;;(defun ml-inst_form (used-vars %insttyl ob)
;;;   (if %insttyl
;;;      (let ((%renames nil)
;;;            (%changed-types (mapcar #'cdr %insttyl))
;;;            (%used-varnames (var-name-list used-vars 'inst))) 
;;;         (instin-fm ob))
;;;      ob))                     ; ml-inst-in-fm

;;; GH:duplicated code of ml-inst-in for forms and terms
(defun ml-inst_term (used-vars %insttyl ob)
   (if %insttyl
      (let ((%renames nil)
            (%changed-types (mapcar #'cdr %insttyl))
            (%used-varnames (var-name-list used-vars 'inst))) 
         (instin-tm ob))
      ob))                     ; ml-inst-in-tm


;;; instantiate types in a type
;;; record values of compound types to save re-traversal
(defun instin-type (ty)
   (cond
      ((revassoc1 ty %insttyl))
      ((is-vartype ty) ty)
      ((let* ((constyoptyargs (ml-dest_type ty))
               (tyop (car constyoptyargs))
               (tyargs (cdr constyoptyargs)))
            (let ((newty (make-type tyop (mapcar #'instin-type tyargs))))
               (push (cons newty ty) %insttyl)
               newty))
         )))  ;instin-type

;;; instantiate types in a formula
(defun instin-fm (fm)
   (case (form-class fm)
      ((conj disj imp) ; iff deleted [TFM 90.01.20]
         (make-conn-form (get-conn fm)
            (instin-fm (get-left-form fm))
            (instin-fm (get-right-form fm))))
      ((forall exists)
         (make-quant-form (get-quant fm)
            (instin-tm (get-quant-var fm))
            (instin-fm (get-quant-body fm))))
      (pred (make-pred-form (get-pred-sym fm)
            (instin-tm (get-pred-arg fm))))
      (t (lcferror 'instin-fm)))
   )    ; instin-fm



;;; instantiate types in a term
(defun instin-tm (tm)
   (case (term-class tm)
      (var (instin-var tm))
      (const (ml-mk_const (get-const-name tm)
            (instin-type (get-type tm))))
      (abs (ml-mk_abs (instin-tm (get-abs-var tm))
            (instin-tm (get-abs-body tm))))
      (comb (let ((rator (instin-tm (get-rator tm)))
               (rand  (instin-tm (get-rand tm))))
            (let ((tyargs (cdr (ml-dest_type (get-type rator)))))
               (make-comb rator rand (second tyargs)))))
      (t (lcferror 'instin-tm)))
   )    ; instin-tm



;;; prime tok until it is not one of the tokl
;;; TFM for Version 1.12 [90.11.25]
;;; replaces a call to "variant-name" in instin-var below.
(defun variant-name2 (tokl tok)
   (while (memq tok tokl) (setq tok (concat tok '|'|)))
   tok)  ; variant-name2


;;; instantiate types in a variable
;;; renames variables whose type may change
;;; the new name differs from all previous names
;;; call to "variant-name" replaced by call to variant-name2
;;; [TFM 90.11.25]
(defun instin-var (tm)
   (let ((name (get-var-name tm)) (ty (get-type tm)))
      (cond ((assq1 tm %renames))
         ((exists #'(lambda (cty) (ml-type_in_type cty ty))
               %changed-types)
            (let ((newname (variant-name2 %used-varnames name)))
               (let ((newv (mk_realvar newname (instin-type ty))))
                  (push newname %used-varnames)
                  (push (cons tm newv) %renames)
                  newv)))
         (t (push (cons tm tm) %renames) tm))
      ))   ; instin-var



;;; variable renaming - primarily for storing axioms and theorems
;;; forces all variable names in a scope to be distinct
;;; creates new names (identifiers) for all genvars

;;; We don't allow genvars on theory files because
;;; calling genvar should always make a variable not already present
;;; in the current LCF session (in particular, not read from a theory file).

;;; the implementation of scopes should be changed to use an environment,
;;; without side-effects, rather than the hack of forget-var

;;; rename_term used nowhere in HOL 88: deleted		[TFM 90.06.01]
;;; (dml |rename_term| 1 ml-rename_term (|term| -> |term|))

;;; Not used: deleted					[TFM 90.06.01] 
;;; (defun ml-rename_term (ob)
;;;   (let ((%renames nil)  (%used-varnames nil))
;;;      (rename-vars-tm ob)))

;;; No formulas in HOL: rename_form deleted		[TFM 90.04.19]
;;;(dml |rename_form| 1 ml-rename_form (|form| -> |form|))

(defun ml-rename_form (ob)
   (let ((%renames nil)  (%used-varnames nil))
      (rename-vars-fm ob)))



;;; rename variables in a formula

(defun rename-vars-fm (fm)
   (case (form-class fm)
       ((conj disj imp) ; iff deleted [TFM 90.01.20]
         (make-conn-form (get-conn fm)
            (rename-vars-fm (get-left-form fm))
            (rename-vars-fm (get-right-form fm))))
      ((forall exists)
         (let ((quant (get-quant fm))
               (bv (rename-vars-tm (get-quant-var fm)))
               (body (rename-vars-fm (get-quant-body fm))))
            (forget-var (get-quant-var fm))
            (make-quant-form quant bv body)))
      (pred (make-pred-form (get-pred-sym fm)
            (rename-vars-tm (get-pred-arg fm))))
      (t (lcferror 'rename-vars-fm )))
   )    ; rename-vars-fm



;;; rename variables in a term
(defun rename-vars-tm (tm)
   (case (term-class tm)
      (var (rename-var tm))
      (const tm)
      (abs (let ((bv (rename-vars-tm (get-abs-var tm)))
               (body (rename-vars-tm (get-abs-body tm))))
            (forget-var (get-abs-var tm))
            (ml-mk_abs bv body)))
      (comb (ml-mk_comb (rename-vars-tm (get-rator tm))
            (rename-vars-tm (get-rand tm))))
      (t (lcferror 'rename-vars-tm)))
   )    ; rename-vars-tm


;;; rename a variable
;;; primes each variable to differ from all previous names
;;; renames all genvars
(defun rename-var (v)
   (let ((name (get-var-name v)) (ty (get-type v)))
      (cond ((assq1 v %renames))
         (t (let ((newname (variant-name %used-varnames 
                        (if (idenp name) name (gensym-interned)))))
               (let ((newv (mk_realvar newname ty)))
                  (push newname %used-varnames)
                  (push (cons v newv) %renames)
                  newv))))
      ))   ; rename-var


;;; forget about a variable once leaving its scope
;;; to allow (\x.x), (\x.x) without priming the second x 
;;; change needed by Mike Gordon (this is a mystery to me: MJCG 15/10/89!)
(defun forget-var (v)
   (let ((v2 (assq1 v %renames)))
      (setq %used-varnames (delq (get-var-name v2) %used-varnames))
      (push (cons v nil) %renames))
   )                               ; forget-var


;;; Code below added on 15/10/89 by MJCG to correct a variable capture bug 
;;; found by ICL Defence Systems.

;;; Returns list of variables "x:ty2" in a term where there is a preceding
;;; "x:ty1" in the term with ty1 is not equal to ty2.
;;; (It is possible that the old code could be debugged to avoid this
;;; inefficient second pass, MJCG could not see how and installed this patch
;;; as a temporary fix.)
;;; Patched 25/01/94 by MJCG to return list of variables "x2:ty2" in a term 
;;; where there is a preceding "x1:ty1" in the term 
;;; with x1 equal to x2 up to priming and ty1 is not equal to ty2.
;;; Fixes a bug found by Joakim Von Wright

(defun strip-primes (tok) (strip-primes-aux(reverse(exploden tok))))

(defun strip-primes-aux (tokl)
 (cond ((eq (car tokl) 39) (strip-primes-aux(cdr tokl)))
       (t (imploden(reverse tokl)))))

(defun get-inst-rename-list (tm)
  (case (term-class tm)
        (var (let ((p (assq (strip-primes(get-var-name tm))
                            %clash-danger-vars)))
              (cond (p (and (not (eq (get-type tm) (cdr p))) (list tm)))
                    (t (push (cons (strip-primes(cadr tm)) (cddr tm))
                             %clash-danger-vars) nil))))
        (const nil)
        (abs (append (get-inst-rename-list (get-abs-var tm))
                     (get-inst-rename-list (get-abs-body tm))))
        (comb (append (get-inst-rename-list (get-rator tm))
                      (get-inst-rename-list (get-rand tm))))
        (t (lcferror 'get-inst-rename-list))))

(defun inst-renames (tm) 
 (setq %clash-danger-vars nil)
 (get-inst-rename-list tm))

(dml |inst_rename_list| 1 inst-renames (|term| -> (|term| |list|)))

;;; Checks whether any type in tyl occurs in term tm
;;; Added 15/10/89 by MJCG as an optimization of INST_TYPE.
(defun typel-in-tm (tyl tm)
  (and tyl (or (ml-type_in_term (car tyl) tm)
               (typel-in-tm (cdr tyl) tm))))

;;; Checks (i) that the second component of every pair in inst_tylist
;;; is a type variable, and (ii) that none of these type variables occur
;;; in any of the terms in asl. Returns the free variables in asl.
;;; Added 15/10/89 by MJCG as an optimization of INST_TYPE.
(defun ml-inst_check (inst_tylist asl)
 (prog (tyvars vars)
       (setq tyvars nil)
       (setq vars nil)
  l1   (cond ((null inst_tylist) (go l2))
             ((is-vartype(cdar inst_tylist))
              (setq tyvars (cons (cdar inst_tylist) tyvars))
              (setq inst_tylist (cdr inst_tylist))
              (go l1))
             (t (failwith '|INST_TYPE: attempt to instantiate non-tyvar|)))
  l2   (cond ((null asl) (return vars))
             ((typel-in-tm tyvars (car asl)) 
              (failwith
                '|INST_TYPE: type variable free in assumptions|)))
       (setq vars (nconc (freevars (car asl)) vars))
       (setq asl (cdr asl))
       (go l2)))


(dml 
 |inst_check| 
 2 
 ml-inst_check
 ((((|type| |#| |type|) |list|) |#| (|term| |list|)) |->| (|term| |list|)))