Source file pred_elim.ml
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
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
(** {1 Blocked Clause Elimination} *)
open Logtk
open Libzipperposition
let k_enabled = Flex_state.create_key ()
let k_check_at = Flex_state.create_key ()
let k_inprocessing = Flex_state.create_key ()
let k_max_resolvents = Flex_state.create_key ()
let k_check_gates = Flex_state.create_key ()
let _enabled = ref false
let _check_gates = ref true
let _inprocessing = ref false
let _check_at = ref 10
let _max_resolvents = ref (-1)
let section = Util.Section.make ~parent:Const.section "pred-elim"
module A = Libzipperposition_avatar
module type S = sig
module Env : Env.S
(** {5 Registration} *)
val setup : unit -> unit
val begin_fixpoint : unit -> unit
val fixpoint_step : unit -> bool
val end_fixpoint : unit -> unit
end
module Make(E : Env.S) : S with module Env = E = struct
module Env = E
module C = Env.C
module CS = C.ClauseSet
module L = Literal
module T = Term
type logic =
| NEqFO
| EqFO
| Unsupported
exception UnsupportedLogic
type pred_elim_info =
{
sym : ID.t;
mutable pos_cls : CS.t;
mutable neg_cls : CS.t;
mutable offending_cls : CS.t;
mutable possible_gates : CS.t;
mutable is_gate : (C.t list * C.t list) option;
mutable sq_var_weight : float;
mutable num_lits : int;
mutable last_check : (float * int) option;
mutable heap_idx : int;
}
let pp_task out task =
CCFormat.fprintf out
"%a {@. +: @[%a@];@. -:@[%a@];@. ?:@[%a@]@. g:@[%b@]@. v^2:@[%g@]; |l|:@[%d@]; @.}@."
ID.pp task.sym (CS.pp C.pp) task.pos_cls (CS.pp C.pp) task.neg_cls
(CS.pp C.pp) task.offending_cls (CCOpt.is_some task.is_gate) task.sq_var_weight
task.num_lits
module TaskWrapper = struct
type t = pred_elim_info
let idx task = task.heap_idx
let set_idx task idx =
task.heap_idx <- idx
let lt a b =
let card t =
CS.cardinal t.pos_cls + CS.cardinal t.neg_cls
in
let card_a = card a and card_b = card b in
card_a < card_b || (card_a = card_b && ID.compare a.sym b.sym < 0)
end
module TaskSet = CCSet.Make(struct
type t = pred_elim_info
let compare t1 t2 = ID.compare t1.sym t2.sym
end)
let _task_queue = ref TaskSet.empty
let _newly_added = ref CS.empty
let _tracked = ref CS.empty
let _logic = ref NEqFO
let refine_logic new_val =
if !_logic != Unsupported then (
_logic := new_val
)
let _ignored_symbols = ref ID.Set.empty
let mk_pred_elim_info sym =
{
sym; pos_cls = CS.empty; neg_cls = CS.empty;
offending_cls=CS.empty; possible_gates = CS.empty;
is_gate=None; sq_var_weight=0.0; last_check=None; heap_idx=(-1); num_lits=0;
}
let _pred_sym_idx = ref ID.Map.empty
let calc_sq_var cl =
let n = List.length (Literals.vars (C.lits cl)) in
float_of_int (n * n)
let get_sym_sign lit =
match lit with
| L.Equation(lhs,rhs,_) ->
let sign = L.is_pos lit in
let is_poly =
not (Type.VarSet.is_empty (T.ty_vars lhs))
|| not (Type.VarSet.is_empty (T.ty_vars rhs))
in
if not is_poly && T.is_fo_term lhs && T.is_fo_term rhs then (
if Type.is_prop (T.ty lhs) then (
if L.is_predicate_lit lit then (
let hd_sym = T.head_exn lhs in
Some (hd_sym, sign)
) else (
Util.debugf ~section 1 "unsupported because of @[%a@]@." (fun k -> k L.pp lit);
_logic := Unsupported;
raise UnsupportedLogic;
)) else (refine_logic EqFO; None)
) else (
_logic := Unsupported;
Util.debugf ~section 1 "unsupported because of @[%a@]@." (fun k -> k L.pp lit);
raise UnsupportedLogic)
| _ -> None
let possibly_ignore_sym entry =
let card s = CS.cardinal s in
let possible_resolvents =
match entry.is_gate with
| Some(pos_gates,neg_gates) ->
List.length pos_gates * card entry.neg_cls +
List.length neg_gates * card entry.pos_cls
| None ->
card entry.neg_cls * card entry.pos_cls
in
if Env.flex_get k_max_resolvents < 0 then ()
else (
if possible_resolvents > Env.flex_get k_max_resolvents then (
_pred_sym_idx := ID.Map.remove entry.sym !_pred_sym_idx;
_ignored_symbols := ID.Set.add entry.sym !_ignored_symbols;
if TaskSet.mem entry !_task_queue then (
_task_queue := TaskSet.remove entry !_task_queue
)
)
)
let scan_cl_lits ?(handle_gates=true) cl =
let num_vars = List.length @@ Literals.vars (C.lits cl) in
let is_flat = function
| L.Equation(lhs,_,_) as lit ->
assert (L.is_predicate_lit lit);
let args = T.args lhs in
List.for_all T.is_var args &&
T.Set.cardinal (T.Set.of_list args) == List.length args
| _ -> assert false
in
let update_idx pos neg offending gates num_vars cl =
let update ~action sym =
_pred_sym_idx := ID.Map.update sym (fun old ->
let entry = CCOpt.get_or ~default:(mk_pred_elim_info sym) old in
begin match action with
| `Pos ->
entry.pos_cls <- CS.add cl entry.pos_cls;
| `Neg ->
entry.neg_cls <- CS.add cl entry.neg_cls;
possibly_ignore_sym entry;
| `Offending ->
entry.offending_cls <- CS.add cl entry.offending_cls;
if TaskSet.mem entry !_task_queue then (
_task_queue := TaskSet.remove entry !_task_queue;
)
| `Gates ->
if handle_gates then(
entry.possible_gates <- CS.add cl entry.possible_gates
)
end;
if action != `Gates then (
entry.sq_var_weight <- entry.sq_var_weight +. calc_sq_var cl;
entry.num_lits <- entry.num_lits + C.length cl
);
possibly_ignore_sym entry;
if ID.Set.mem entry.sym !_ignored_symbols
then None
else Some entry
) !_pred_sym_idx
in
ID.Set.iter (update ~action:`Pos) pos;
ID.Set.iter (update ~action:`Neg) neg;
ID.Set.iter (update ~action:`Offending) offending;
ID.Set.iter (update ~action:`Gates) gates;
in
let pos,neg,offending,gates = CCArray.foldi (fun ((pos,neg,offending,gates) as acc) idx lit ->
let symbol_is_fresh sym =
not (ID.Set.mem sym pos) && not (ID.Set.mem sym neg) &&
not (ID.Set.mem sym offending) && not (ID.Set.mem sym !_ignored_symbols)
in
(match get_sym_sign lit with
| Some (sym, sign) when symbol_is_fresh sym ->
let is_offending = ref false in
for i = idx+1 to (C.length cl)-1 do
(match get_sym_sign (C.lits cl).(i) with
| Some(sym', _) ->
is_offending := !is_offending || ID.equal sym sym'
| None -> () )
done;
if !is_offending then (
pos,neg,ID.Set.add sym offending,gates
) else (
let gates = if is_flat lit then ID.Set.add sym gates else gates in
if sign then (ID.Set.add sym pos,neg,offending,gates)
else (pos, ID.Set.add sym neg,offending,gates))
| _ -> acc)
) (ID.Set.empty, ID.Set.empty, ID.Set.empty, ID.Set.empty) (C.lits cl) in
update_idx pos neg offending gates num_vars cl
let react_clause_addded cl =
if !_logic != Unsupported then(
if not (CS.mem cl !_tracked) then (
Util.debugf ~section 5 "added:@[%a@]" (fun k -> k C.pp cl);
_tracked := CS.add cl !_tracked;
scan_cl_lits ~handle_gates:false cl);
Signal.ContinueListening
) else Signal.StopListening
let react_clause_removed cl =
if !_logic != Unsupported then (
let should_retry task =
CS.is_empty task.offending_cls &&
not (ID.Set.mem task.sym !_ignored_symbols) &&
(match task.last_check with
| Some(old_sq_var_sum, old_num_lit) ->
task.sq_var_weight < old_sq_var_sum || task.num_lits < old_num_lit
| None -> true)
in
let handle_gate sign task cl =
match task.is_gate with
| Some(pos_cls, neg_cls) ->
if sign && CCList.mem ~eq:C.equal cl pos_cls
|| (not sign) && CCList.mem ~eq:C.equal cl neg_cls then (
task.pos_cls <- CS.add_list task.pos_cls pos_cls;
task.neg_cls <- CS.add_list task.neg_cls neg_cls;
task.is_gate <- None
)
| None -> ()
in
let handled = ref ID.Set.empty in
if not (CS.mem cl !_newly_added) &&
CS.mem cl !_tracked then (
_tracked := CS.remove cl !_tracked;
Array.iteri (fun idx lit ->
match get_sym_sign lit with
| Some(sym, sign) when not (ID.Set.mem sym !handled) ->
let is_offending = ref false in
for i = idx+1 to (C.length cl) -1 do
match get_sym_sign (C.lits cl).(i) with
| Some (sym', sign) ->
is_offending := !is_offending || ID.equal sym sym'
| None -> ()
done;
_pred_sym_idx := ID.Map.update sym (function
| Some task ->
task.sq_var_weight <- task.sq_var_weight -. calc_sq_var cl;
task.num_lits <- task.num_lits - C.length cl;
if !is_offending then (
task.offending_cls <- CS.remove cl task.offending_cls
) else if sign then (
handle_gate sign task cl;
task.pos_cls <- CS.remove cl task.pos_cls;
) else (
handle_gate sign task cl;
task.neg_cls <- CS.remove cl task.neg_cls;
);
if not (TaskSet.mem task !_task_queue) && should_retry task then (
Util.debugf ~section 10 "retrying @[%a@]@." (fun k -> k pp_task task);
_task_queue := TaskSet.add task !_task_queue
);
Some task
| None -> None ) !_pred_sym_idx;
| _ -> ()
) (C.lits cl));
Signal.ContinueListening)
else Signal.StopListening
let replace_clauses task clauses =
Util.debugf ~section 1 "replaced clauses(%a):@. regular:@[%a@]@. gates:@[%a@]@."
(fun k -> k ID.pp task.sym (CS.pp C.pp) (CS.union task.pos_cls task.neg_cls)
(CCOpt.pp (CCPair.pp (CCList.pp C.pp) (CCList.pp C.pp))) task.is_gate);
Util.debugf ~section 1 "resolvents: @[%a@]@." (fun k -> k (CCList.pp C.pp) clauses);
_ignored_symbols := ID.Set.add task.sym !_ignored_symbols;
let remove iter =
Env.remove_active iter;
Env.remove_passive iter;
Env.remove_simpl iter;
Iter.iter (fun c -> (C.mark_redundant c);
if CS.mem c !_newly_added then (
_newly_added := CS.remove c !_newly_added;
ignore (react_clause_removed c);
)
) iter;
in
assert(CS.is_empty task.offending_cls);
remove (CS.to_iter task.pos_cls);
remove (CS.to_iter task.neg_cls);
(match task.is_gate with
| Some(pos_cls, neg_cls) ->
remove (CCList.to_iter pos_cls);
remove (CCList.to_iter neg_cls)
| None -> ());
_newly_added := CS.add_list !_newly_added clauses;
List.iter (fun cl -> ignore (react_clause_addded cl)) clauses;
_pred_sym_idx := ID.Map.remove task.sym !_pred_sym_idx
let check_if_gate task =
let sym = task.sym in
let gates_l = CS.to_list task.possible_gates in
let filter_gates ~sign ~lit_num_filter =
List.filter (fun cl ->
lit_num_filter (Array.length (C.lits cl)) &&
(match (CCArray.find_idx (fun lit ->
match get_sym_sign lit with
| Some(sym', sign') -> ID.equal sym sym' && sign = sign'
| None -> false) (C.lits cl)) with
| Some (i, lit) ->
let free_vars = T.VarSet.of_list (L.vars lit) in
CCOpt.is_none (CCArray.find_map_i (fun j lit' ->
if (i=j || T.VarSet.subset (T.VarSet.of_list (L.vars lit')) free_vars) then None
else Some j
) (C.lits cl))
| _ -> false))
gates_l
in
let find_and_or bin_clauses long_clauses =
CCList.find_map (fun long_cl ->
let sym_lits, other_lits = List.partition (fun lit ->
match get_sym_sign lit with
| Some(sym',_) -> ID.equal sym sym'
| _ -> false
) (CCArray.to_list @@ C.lits long_cl) in
assert (List.length sym_lits = 1);
let sym_name_lit = List.hd sym_lits in
let bin_gates = CCArray.of_list bin_clauses in
if List.length other_lits > CCArray.length bin_gates then None
else (
let matched = CCBV.create ~size:(CCArray.length bin_gates) false in
let is_gate = List.for_all (fun lit ->
let found = ref false in
let i = ref 0 in
while not !found && !i < CCArray.length bin_gates do
let cl = bin_gates.(!i) in
if not (CCBV.get matched !i) then (
let idx_name_opt = CCArray.find_idx (fun lit ->
match get_sym_sign lit with
| Some(sym',_) -> ID.equal sym sym'
| None -> false
) (C.lits cl) in
let idx_name, _ = CCOpt.get_exn idx_name_opt in
let name_lit = L.negate (C.lits cl).(idx_name) in
let other_lit = L.negate (C.lits cl).(1 - idx_name) in
let is_matched =
not @@ Iter.is_empty
(L.variant (lit,0) (other_lit,1)
|> Iter.filter (fun (subst,_) ->
not @@ Iter.is_empty @@
L.variant ~subst (sym_name_lit, 0) (name_lit,1)))
in
if is_matched then (
CCBV.set matched !i;
found := true
));
incr i;
done;
!found
) other_lits in
let bin_cls = CCBV.select matched bin_gates in
if is_gate then Some(long_cl, bin_cls)
else None))
long_clauses
in
let check_and () =
let pos_gates = filter_gates ~sign:true ~lit_num_filter:(fun n -> n >= 3) in
let neg_gates = filter_gates ~sign:false ~lit_num_filter:((=) 2) in
match find_and_or neg_gates pos_gates with
| Some (pos_cl, neg_cls) ->
let to_remove = CS.of_list (pos_cl :: neg_cls) in
task.neg_cls <- CS.diff task.neg_cls to_remove;
task.pos_cls <- CS.diff task.pos_cls to_remove;
task.is_gate <- Some([pos_cl], neg_cls);
true
| None -> false
in
let check_or () =
let pos_gates = filter_gates ~sign:true ~lit_num_filter:((=) 2) in
let neg_gates = filter_gates ~sign:false ~lit_num_filter:(fun n -> n >= 3) in
match find_and_or pos_gates neg_gates with
| Some(neg_cl, pos_cls) ->
let to_remove = CS.of_list (neg_cl :: pos_cls) in
task.neg_cls <- CS.diff task.neg_cls to_remove;
task.pos_cls <- CS.diff task.pos_cls to_remove;
task.is_gate <- Some(pos_cls, [neg_cl]);
true
| None -> false
in
let check_ite () = false in
if Env.flex_get k_check_gates then (
ignore (check_and () || check_or () || check_ite ())
)
let schedule_tasks () =
ID.Map.iter (fun _ task ->
check_if_gate task;
Util.debugf ~section 5 "initially: @[%a@]" (fun k -> k pp_task task);
if CS.is_empty task.offending_cls then (
_task_queue := TaskSet.add task !_task_queue
)) !_pred_sym_idx
let find_lit_by_sym sym sign cl =
CCOpt.get_exn (CCArray.find_map_i (fun idx lit ->
match get_sym_sign lit with
| Some (sym', sign') when ID.equal sym sym' && sign = sign' ->
Some (idx, CCOpt.get_exn (L.View.get_lhs lit))
| _ -> None
) (C.lits cl))
let is_tauto c =
Literals.is_trivial (C.lits c) || Trail.is_trivial (C.trail c)
let neq_resolver ~sym ~pos_cl ~neg_cl =
let pos_sc, neg_sc = 0, 1 in
let pos_idx, pos_term = find_lit_by_sym sym true pos_cl in
let neg_idx, neg_term = find_lit_by_sym sym false neg_cl in
try
let subst = Unif.FO.unify_syn (pos_term, pos_sc) (neg_term, neg_sc) in
let renaming = Subst.Renaming.create () in
let lits =
(List.map (fun lit ->
L.apply_subst renaming subst (lit, pos_sc))
(CCArray.except_idx (C.lits pos_cl) pos_idx)) @
(List.map (fun lit ->
L.apply_subst renaming subst (lit, neg_sc))
(CCArray.except_idx (C.lits neg_cl) neg_idx))
in
let proof =
Proof.Step.simp
~tags:[Proof.Tag.T_cannot_orphan]
~rule:(Proof.Rule.mk "dp-resolution")
[C.proof_parent_subst renaming (pos_cl,pos_sc) subst;
C.proof_parent_subst renaming (neg_cl,neg_sc) subst]
in
let c =
C.create ~penalty:(max (C.penalty pos_cl) (C.penalty neg_cl))
~trail:(C.trail_l [pos_cl; neg_cl]) lits proof
in
CCOpt.return_if (not (is_tauto c)) c
with Unif.Fail -> None
let eq_resolver ~sym ~pos_cl ~neg_cl =
let pos_sc, neg_sc = 0, 1 in
let renaming = Subst.Renaming.create () in
let subst = Subst.empty in
let pos_cl' = C.apply_subst ~renaming (pos_cl, pos_sc) subst in
let neg_cl' = C.apply_subst ~renaming (neg_cl, neg_sc) subst in
let pos_idx, pos_term = find_lit_by_sym sym true pos_cl' in
let neg_idx, neg_term = find_lit_by_sym sym false neg_cl' in
let pos_args, neg_args = CCPair.map_same T.args (pos_term, neg_term) in
let lits =
(List.map (fun (p,n) -> L.mk_neq p n) (List.combine pos_args neg_args)) @
(CCArray.except_idx (C.lits pos_cl') pos_idx) @
(CCArray.except_idx (C.lits neg_cl') neg_idx)
in
let proof =
Proof.Step.simp
~tags:[Proof.Tag.T_cannot_orphan]
~rule:(Proof.Rule.mk "dp-resolution")
[C.proof_parent_subst renaming (pos_cl,pos_sc) subst;
C.proof_parent_subst renaming (neg_cl,neg_sc) subst]
in
let c =
C.create ~penalty:(max (C.penalty pos_cl') (C.penalty neg_cl'))
~trail:(C.trail_l [pos_cl'; neg_cl']) lits proof
in
CCOpt.return_if (not (is_tauto c)) c
let get_resolver () =
if !_logic = NEqFO then neq_resolver else eq_resolver
let calc_resolvents ~sym ~pos ~neg =
CCList.flat_map (fun pos_cl ->
CCList.filter_map (fun neg_cl ->
get_resolver () ~sym ~pos_cl ~neg_cl
) neg
) pos
let do_pred_elim () =
let removed_cls = ref None in
let updated_removed inc =
match !removed_cls with
| None -> removed_cls := Some inc
| Some inc' -> removed_cls := Some (inc' + inc)
in
let process_task task =
assert(CS.is_empty task.offending_cls);
let pos_cls, neg_cls =
CCPair.map_same CS.to_list (task.pos_cls, task.neg_cls)
in
let sym = task.sym in
let resolvents, pos_gates, neg_gates =
match task.is_gate with
| Some (pos_gates, neg_gates) ->
((calc_resolvents ~sym ~pos:pos_gates ~neg:neg_cls)
@ (calc_resolvents ~sym ~pos:pos_cls ~neg:neg_gates)), pos_gates, neg_gates
| None -> calc_resolvents ~sym ~pos:pos_cls ~neg:neg_cls, [], []
in
let new_sq_var_weight, new_lit_num =
List.fold_left (fun (acc_sq, acc_lit_num) cl ->
acc_sq +. calc_sq_var cl, acc_lit_num + C.length cl) (0.0, 0) resolvents
in
let old_clauses =
CS.cardinal task.pos_cls + CS.cardinal task.neg_cls +
List.length pos_gates + List.length neg_gates
in
let num_new_cls = List.length resolvents in
if new_sq_var_weight <= task.sq_var_weight ||
new_lit_num <= task.num_lits ||
num_new_cls < old_clauses then (
Util.debugf ~section 5 "replacing: @[%a@] (%d/%d) "
(fun k -> k ID.pp task.sym old_clauses (num_new_cls));
updated_removed (old_clauses - num_new_cls);
replace_clauses task resolvents;
) else (
task.last_check <- Some (task.sq_var_weight, task.num_lits)
)
in
let module S = TaskSet in
while not (S.is_empty !_task_queue) do
let task = S.min_elt !_task_queue in
_task_queue := S.remove task !_task_queue;
if not (ID.Set.mem task.sym !_ignored_symbols) then(
Util.debugf ~section 5 "checking: @[%a@]" (fun k -> k pp_task task);
process_task (task)
)
done;
Env.add_passive (CS.to_iter !_newly_added);
_newly_added := CS.empty;
!removed_cls
let steps = ref 0
let do_predicate_elimination () =
steps := (!steps + 1) mod (Env.flex_get k_check_at);
if !steps = 0 then (
ignore( do_pred_elim ());
)
let initialize () =
let init_clauses =
CS.to_list (Env.ProofState.ActiveSet.clauses ())
@ CS.to_list (Env.ProofState.PassiveSet.clauses ())
in
begin try
Util.debugf ~section 5 "init_cl: @[%a@]@."
(fun k -> k (CCList.pp C.pp) init_clauses);
let init_clause_num = List.length init_clauses in
CCFormat.printf "%% PE start: %d@." init_clause_num;
List.iter (fun cl ->
scan_cl_lits cl;
_tracked := CS.add cl !_tracked;
) init_clauses;
schedule_tasks ();
Util.debugf ~section 5 "state:@[%a@]@."
(fun k -> k (Iter.pp_seq pp_task) (ID.Map.values !_pred_sym_idx));
Util.debugf ~section 1 "logic has%sequalities"
(fun k -> k (if !_logic == EqFO then " " else " no "));
Signal.on Env.ProofState.PassiveSet.on_add_clause react_clause_addded;
Signal.on Env.ProofState.PassiveSet.on_remove_clause react_clause_removed;
Signal.on Env.ProofState.ActiveSet.on_add_clause react_clause_addded;
Signal.on Env.ProofState.ActiveSet.on_remove_clause react_clause_removed;
Signal.on_every Env.on_forward_simplified (fun (c, new_state) ->
if !_logic != Unsupported then (
match new_state with
| Some c' ->
ignore(react_clause_removed c);
ignore(react_clause_addded c')
| _ -> ignore(react_clause_removed c)
));
ignore(do_pred_elim ());
Util.debugf ~section 5 "after elim: @[%a@]@."
(fun k -> k (CS.pp C.pp) (Env.ProofState.PassiveSet.clauses ()));
Util.debugf ~section 5 "state:@[%a@]@."
(fun k -> k (Iter.pp_seq pp_task) (ID.Map.values !_pred_sym_idx));
let clause_diff =
init_clause_num -
(Iter.length (Env.get_active ()) + Iter.length (Env.get_passive ())) in
CCFormat.printf "%% PE eliminated: %d@." clause_diff;
if Env.flex_get k_inprocessing then (
Env.add_clause_elimination_rule ~priority:2 "pred_elim"
do_predicate_elimination
) else raise UnsupportedLogic
with UnsupportedLogic ->
Util.debugf ~section 1 "logic is unsupported" CCFun.id;
_logic := Unsupported;
_pred_sym_idx := ID.Map.empty
end;
Signal.StopListening
let register () =
Signal.on Env.on_start initialize
let fixpoint_active = ref false
let begin_fixpoint () =
fixpoint_active := true;
E.flex_add k_enabled !_enabled;
E.flex_add k_max_resolvents !_max_resolvents;
E.flex_add k_check_gates !_check_gates;
let init_clauses =
CS.to_list (Env.ProofState.ActiveSet.clauses ())
@ CS.to_list (Env.ProofState.PassiveSet.clauses ())
in
begin try
List.iter (fun cl ->
scan_cl_lits cl;
_tracked := CS.add cl !_tracked;
) init_clauses;
schedule_tasks ();
Signal.on Env.ProofState.PassiveSet.on_add_clause (fun c ->
if !fixpoint_active then react_clause_addded c
else Signal.StopListening
);
Signal.on Env.ProofState.PassiveSet.on_remove_clause (fun c ->
if !fixpoint_active then react_clause_removed c
else Signal.StopListening
);
let ans = (do_pred_elim ()) in
Util.debugf ~section 1 "Clause number changed for %a" (fun k -> k (CCOpt.pp CCInt.pp) ans)
with UnsupportedLogic ->
Util.debugf ~section 1 "logic is unsupported" CCFun.id;
_logic := Unsupported;
_pred_sym_idx := ID.Map.empty
end
let fixpoint_step () =
let ans = do_pred_elim () in
Util.debugf ~section 1 "Clause number changed for %a" (fun k -> k (CCOpt.pp CCInt.pp) ans);
CCOpt.is_some ans
let end_fixpoint () =
_logic := Unsupported;
_pred_sym_idx := ID.Map.empty;
fixpoint_active := false
let setup () =
if Env.flex_get k_enabled then (
if not (Env.flex_get A.k_avatar_enabled) then (register ())
else (
CCFormat.printf "AVATAR is not yet compatible with PredElim@."
)
)
end
let extension =
let action env =
let module E = (val env : Env.S) in
let module PredElim = Make(E) in
E.flex_add k_enabled !_enabled;
E.flex_add k_check_at !_check_at;
E.flex_add k_inprocessing !_inprocessing;
E.flex_add k_max_resolvents !_max_resolvents;
E.flex_add k_check_gates !_check_gates;
PredElim.setup ()
in
{ Extensions.default with Extensions.
name="pred_elim";
prio = 90;
env_actions=[action];
}
let () =
Options.add_opts [
"--pred-elim", Arg.Bool ((:=) _enabled), " enable predicate elimination";
"--pred-elim-check-gates", Arg.Bool ((:=) _check_gates), " enable recognition of gate clauses";
"--pred-elim-inprocessing", Arg.Bool ((:=) _inprocessing), " predicate elimination as inprocessing rule";
"--pred-elim-check-at", Arg.Int ((:=) _check_at), " when to perform predicate elimination inprocessing";
"--pred-elim-max-resolvents", Arg.Int ((:=) _max_resolvents), " after how many resolvents to stop tracking a symbol";
]