GCC Code Coverage Report
Directory: . Exec Total Coverage
File: src/theory/theory_inference_manager.cpp Lines: 224 246 91.1 %
Date: 2021-08-06 Branches: 356 842 42.3 %

Line Exec Source
1
/******************************************************************************
2
 * Top contributors (to current version):
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 *   Andrew Reynolds, Gereon Kremer, Mathias Preiner
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 *
5
 * This file is part of the cvc5 project.
6
 *
7
 * Copyright (c) 2009-2021 by the authors listed in the file AUTHORS
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 * in the top-level source directory and their institutional affiliations.
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 * All rights reserved.  See the file COPYING in the top-level source
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 * directory for licensing information.
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 * ****************************************************************************
12
 *
13
 * An inference manager for Theory.
14
 */
15
16
#include "theory/theory_inference_manager.h"
17
18
#include "smt/smt_engine_scope.h"
19
#include "smt/smt_statistics_registry.h"
20
#include "theory/output_channel.h"
21
#include "theory/rewriter.h"
22
#include "theory/theory.h"
23
#include "theory/theory_state.h"
24
#include "theory/uf/equality_engine.h"
25
#include "theory/uf/proof_equality_engine.h"
26
27
using namespace cvc5::kind;
28
29
namespace cvc5 {
30
namespace theory {
31
32
118236
TheoryInferenceManager::TheoryInferenceManager(Theory& t,
33
                                               TheoryState& state,
34
                                               ProofNodeManager* pnm,
35
                                               const std::string& statsName,
36
118236
                                               bool cacheLemmas)
37
    : d_theory(t),
38
      d_theoryState(state),
39
118236
      d_out(t.getOutputChannel()),
40
      d_ee(nullptr),
41
      d_decManager(nullptr),
42
      d_pfee(nullptr),
43
      d_pnm(pnm),
44
      d_cacheLemmas(cacheLemmas),
45
      d_keep(t.getSatContext()),
46
118236
      d_lemmasSent(t.getUserContext()),
47
      d_numConflicts(0),
48
      d_numCurrentLemmas(0),
49
      d_numCurrentFacts(0),
50
118236
      d_conflictIdStats(smtStatisticsRegistry().registerHistogram<InferenceId>(
51
236472
          statsName + "inferencesConflict")),
52
118236
      d_factIdStats(smtStatisticsRegistry().registerHistogram<InferenceId>(
53
236472
          statsName + "inferencesFact")),
54
118236
      d_lemmaIdStats(smtStatisticsRegistry().registerHistogram<InferenceId>(
55
709416
          statsName + "inferencesLemma"))
56
{
57
  // don't add true lemma
58
236472
  Node truen = NodeManager::currentNM()->mkConst(true);
59
118236
  d_lemmasSent.insert(truen);
60
118236
}
61
62
118236
TheoryInferenceManager::~TheoryInferenceManager()
63
{
64
118236
}
65
66
118236
void TheoryInferenceManager::setEqualityEngine(eq::EqualityEngine* ee)
67
{
68
118236
  d_ee = ee;
69
  // if proofs are enabled, also make a proof equality engine to wrap ee
70
  // if it is non-null. If its proof equality engine has already been assigned,
71
  // use it. This is to ensure that all theories use the same proof equality
72
  // engine when in ee-mode=central.
73
118236
  if (d_pnm != nullptr && d_ee != nullptr)
74
  {
75
11959
    d_pfee = d_ee->getProofEqualityEngine();
76
11959
    if (d_pfee == nullptr)
77
    {
78
23792
      d_pfeeAlloc.reset(new eq::ProofEqEngine(d_theoryState.getSatContext(),
79
11896
                                              d_theoryState.getUserContext(),
80
11896
                                              *d_ee,
81
23792
                                              d_pnm));
82
11896
      d_pfee = d_pfeeAlloc.get();
83
11896
      d_ee->setProofEqualityEngine(d_pfee);
84
    }
85
  }
86
118236
}
87
88
118236
void TheoryInferenceManager::setDecisionManager(DecisionManager* dm)
89
{
90
118236
  d_decManager = dm;
91
118236
}
92
93
21469
bool TheoryInferenceManager::isProofEnabled() const { return d_pnm != nullptr; }
94
95
787814
void TheoryInferenceManager::reset()
96
{
97
787814
  d_numConflicts = 0;
98
787814
  d_numCurrentLemmas = 0;
99
787814
  d_numCurrentFacts = 0;
100
787814
}
101
102
217614
bool TheoryInferenceManager::hasSent() const
103
{
104
435228
  return d_theoryState.isInConflict() || d_numCurrentLemmas > 0
105
425658
         || d_numCurrentFacts > 0;
106
}
107
108
eq::ProofEqEngine* TheoryInferenceManager::getProofEqEngine() { return d_pfee; }
109
110
12926
void TheoryInferenceManager::conflictEqConstantMerge(TNode a, TNode b)
111
{
112
12926
  if (!d_theoryState.isInConflict())
113
  {
114
25690
    TrustNode tconf = explainConflictEqConstantMerge(a, b);
115
12845
    trustedConflict(tconf, InferenceId::EQ_CONSTANT_MERGE);
116
  }
117
12926
}
118
119
78961
void TheoryInferenceManager::conflict(TNode conf, InferenceId id)
120
{
121
157922
  TrustNode tconf = TrustNode::mkTrustConflict(conf, nullptr);
122
157922
  return trustedConflict(tconf, id);
123
}
124
125
107863
void TheoryInferenceManager::trustedConflict(TrustNode tconf, InferenceId id)
126
{
127
107863
  d_conflictIdStats << id;
128
107863
  smt::currentResourceManager()->spendResource(id);
129
215726
  Trace("im") << "(conflict " << id << " " << tconf.getProven() << ")"
130
107863
              << std::endl;
131
107863
  d_out.trustedConflict(tconf);
132
107863
  ++d_numConflicts;
133
107863
}
134
135
8
void TheoryInferenceManager::conflictExp(InferenceId id,
136
                                         PfRule pfr,
137
                                         const std::vector<Node>& exp,
138
                                         const std::vector<Node>& args)
139
{
140
8
  if (!d_theoryState.isInConflict())
141
  {
142
    // make the trust node
143
16
    TrustNode tconf = mkConflictExp(pfr, exp, args);
144
    // send it on the output channel
145
8
    trustedConflict(tconf, id);
146
  }
147
8
}
148
149
8
TrustNode TheoryInferenceManager::mkConflictExp(PfRule id,
150
                                                const std::vector<Node>& exp,
151
                                                const std::vector<Node>& args)
152
{
153
8
  if (d_pfee != nullptr)
154
  {
155
    // use proof equality engine to construct the trust node
156
2
    return d_pfee->assertConflict(id, exp, args);
157
  }
158
  // version without proofs
159
12
  Node conf = mkExplainPartial(exp, {});
160
6
  return TrustNode::mkTrustConflict(conf, nullptr);
161
}
162
163
2497
void TheoryInferenceManager::conflictExp(InferenceId id,
164
                                         const std::vector<Node>& exp,
165
                                         ProofGenerator* pg)
166
{
167
2497
  if (!d_theoryState.isInConflict())
168
  {
169
    // make the trust node
170
4768
    TrustNode tconf = mkConflictExp(exp, pg);
171
    // send it on the output channel
172
2384
    trustedConflict(tconf, id);
173
  }
174
2497
}
175
176
4002
TrustNode TheoryInferenceManager::mkConflictExp(const std::vector<Node>& exp,
177
                                                ProofGenerator* pg)
178
{
179
4002
  if (d_pfee != nullptr)
180
  {
181
436
    Assert(pg != nullptr);
182
    // use proof equality engine to construct the trust node
183
436
    return d_pfee->assertConflict(exp, pg);
184
  }
185
  // version without proofs
186
7132
  Node conf = mkExplainPartial(exp, {});
187
3566
  return TrustNode::mkTrustConflict(conf, nullptr);
188
}
189
190
9565754
bool TheoryInferenceManager::propagateLit(TNode lit)
191
{
192
  // If already in conflict, no more propagation
193
9565754
  if (d_theoryState.isInConflict())
194
  {
195
1475
    return false;
196
  }
197
  // Propagate out
198
9564279
  bool ok = d_out.propagate(lit);
199
9564279
  if (!ok)
200
  {
201
62325
    d_theoryState.notifyInConflict();
202
  }
203
9564279
  return ok;
204
}
205
206
211085
TrustNode TheoryInferenceManager::explainLit(TNode lit)
207
{
208
211085
  if (d_pfee != nullptr)
209
  {
210
33287
    return d_pfee->explain(lit);
211
  }
212
177798
  if (d_ee != nullptr)
213
  {
214
355596
    Node exp = d_ee->mkExplainLit(lit);
215
177798
    return TrustNode::mkTrustPropExp(lit, exp, nullptr);
216
  }
217
  Unimplemented() << "Inference manager for " << d_theory.getId()
218
                  << " was asked to explain a propagation but doesn't have an "
219
                     "equality engine or implement the "
220
                     "TheoryInferenceManager::explainLit interface!";
221
}
222
223
12845
TrustNode TheoryInferenceManager::explainConflictEqConstantMerge(TNode a,
224
                                                                 TNode b)
225
{
226
25690
  Node lit = a.eqNode(b);
227
12845
  if (d_pfee != nullptr)
228
  {
229
1540
    return d_pfee->assertConflict(lit);
230
  }
231
11305
  if (d_ee != nullptr)
232
  {
233
22610
    Node conf = d_ee->mkExplainLit(lit);
234
11305
    return TrustNode::mkTrustConflict(conf, nullptr);
235
  }
236
  Unimplemented() << "Inference manager for " << d_theory.getId()
237
                  << " mkTrustedConflictEqConstantMerge";
238
}
239
240
1218327
bool TheoryInferenceManager::lemma(TNode lem, InferenceId id, LemmaProperty p)
241
{
242
2436653
  TrustNode tlem = TrustNode::mkTrustLemma(lem, nullptr);
243
2436653
  return trustedLemma(tlem, id, p);
244
}
245
246
1588514
bool TheoryInferenceManager::trustedLemma(const TrustNode& tlem,
247
                                          InferenceId id,
248
                                          LemmaProperty p)
249
{
250
  // if the policy says to cache lemmas, check the cache and return false if
251
  // we are a duplicate
252
1588514
  if (d_cacheLemmas)
253
  {
254
1533256
    if (!cacheLemma(tlem.getNode(), p))
255
    {
256
1280344
      return false;
257
    }
258
  }
259
308170
  d_lemmaIdStats << id;
260
308170
  smt::currentResourceManager()->spendResource(id);
261
308170
  Trace("im") << "(lemma " << id << " " << tlem.getProven() << ")" << std::endl;
262
  // shouldn't send trivially true or false lemmas
263
308170
  Assert(!Rewriter::rewrite(tlem.getProven()).isConst());
264
308170
  d_numCurrentLemmas++;
265
308172
  d_out.trustedLemma(tlem, p);
266
308168
  return true;
267
}
268
269
bool TheoryInferenceManager::lemmaExp(Node conc,
270
                                      InferenceId id,
271
                                      PfRule pfr,
272
                                      const std::vector<Node>& exp,
273
                                      const std::vector<Node>& noExplain,
274
                                      const std::vector<Node>& args,
275
                                      LemmaProperty p)
276
{
277
  // make the trust node
278
  TrustNode trn = mkLemmaExp(conc, pfr, exp, noExplain, args);
279
  // send it on the output channel
280
  return trustedLemma(trn, id, p);
281
}
282
283
386
TrustNode TheoryInferenceManager::mkLemmaExp(Node conc,
284
                                             PfRule id,
285
                                             const std::vector<Node>& exp,
286
                                             const std::vector<Node>& noExplain,
287
                                             const std::vector<Node>& args)
288
{
289
386
  if (d_pfee != nullptr)
290
  {
291
    // make the trust node from the proof equality engine
292
51
    return d_pfee->assertLemma(conc, id, exp, noExplain, args);
293
  }
294
  // otherwise, not using proofs, explain and make trust node
295
670
  Node ant = mkExplainPartial(exp, noExplain);
296
670
  Node lem = NodeManager::currentNM()->mkNode(kind::IMPLIES, ant, conc);
297
335
  return TrustNode::mkTrustLemma(lem, nullptr);
298
}
299
300
bool TheoryInferenceManager::lemmaExp(Node conc,
301
                                      InferenceId id,
302
                                      const std::vector<Node>& exp,
303
                                      const std::vector<Node>& noExplain,
304
                                      ProofGenerator* pg,
305
                                      LemmaProperty p)
306
{
307
  // make the trust node
308
  TrustNode trn = mkLemmaExp(conc, exp, noExplain, pg);
309
  // send it on the output channel
310
  return trustedLemma(trn, id, p);
311
}
312
313
21422
TrustNode TheoryInferenceManager::mkLemmaExp(Node conc,
314
                                             const std::vector<Node>& exp,
315
                                             const std::vector<Node>& noExplain,
316
                                             ProofGenerator* pg)
317
{
318
21422
  if (d_pfee != nullptr)
319
  {
320
    // make the trust node from the proof equality engine
321
2069
    return d_pfee->assertLemma(conc, exp, noExplain, pg);
322
  }
323
  // otherwise, not using proofs, explain and make trust node
324
38706
  Node ant = mkExplainPartial(exp, noExplain);
325
38706
  Node lem = NodeManager::currentNM()->mkNode(kind::IMPLIES, ant, conc);
326
19353
  return TrustNode::mkTrustLemma(lem, nullptr);
327
}
328
329
121395
bool TheoryInferenceManager::hasCachedLemma(TNode lem, LemmaProperty p)
330
{
331
242790
  Node rewritten = Rewriter::rewrite(lem);
332
242790
  return d_lemmasSent.find(rewritten) != d_lemmasSent.end();
333
}
334
335
uint32_t TheoryInferenceManager::numSentLemmas() const
336
{
337
  return d_numCurrentLemmas;
338
}
339
340
550935
bool TheoryInferenceManager::hasSentLemma() const
341
{
342
550935
  return d_numCurrentLemmas != 0;
343
}
344
345
14619
bool TheoryInferenceManager::assertInternalFact(TNode atom,
346
                                                bool pol,
347
                                                InferenceId id,
348
                                                TNode exp)
349
{
350
43857
  return processInternalFact(
351
43857
      atom, pol, id, PfRule::UNKNOWN, {exp}, {}, nullptr);
352
}
353
354
27959
bool TheoryInferenceManager::assertInternalFact(TNode atom,
355
                                                bool pol,
356
                                                InferenceId id,
357
                                                PfRule pfr,
358
                                                const std::vector<Node>& exp,
359
                                                const std::vector<Node>& args)
360
{
361
27959
  Assert(pfr != PfRule::UNKNOWN);
362
27959
  return processInternalFact(atom, pol, id, pfr, exp, args, nullptr);
363
}
364
365
318943
bool TheoryInferenceManager::assertInternalFact(TNode atom,
366
                                                bool pol,
367
                                                InferenceId id,
368
                                                const std::vector<Node>& exp,
369
                                                ProofGenerator* pg)
370
{
371
318943
  return processInternalFact(atom, pol, id, PfRule::ASSUME, exp, {}, pg);
372
}
373
374
361521
bool TheoryInferenceManager::processInternalFact(TNode atom,
375
                                                 bool pol,
376
                                                 InferenceId iid,
377
                                                 PfRule id,
378
                                                 const std::vector<Node>& exp,
379
                                                 const std::vector<Node>& args,
380
                                                 ProofGenerator* pg)
381
{
382
361521
  d_factIdStats << iid;
383
361521
  smt::currentResourceManager()->spendResource(iid);
384
  // make the node corresponding to the explanation
385
723042
  Node expn = NodeManager::currentNM()->mkAnd(exp);
386
723042
  Trace("im") << "(fact " << iid << " " << (pol ? Node(atom) : atom.notNode())
387
361521
              << " " << expn << ")" << std::endl;
388
  // call the pre-notify fact method with preReg = false, isInternal = true
389
361521
  if (d_theory.preNotifyFact(atom, pol, expn, false, true))
390
  {
391
    // Handled in a theory-specific way that doesn't require equality engine,
392
    // notice we return true, indicating that the fact was processed.
393
    return true;
394
  }
395
361521
  Assert(d_ee != nullptr);
396
723042
  Trace("infer-manager") << "TheoryInferenceManager::assertInternalFact: "
397
723042
                         << (pol ? Node(atom) : atom.notNode()) << " from "
398
361521
                         << expn << " / " << iid << " " << id << std::endl;
399
361521
  if (Configuration::isAssertionBuild())
400
  {
401
    // check that all facts hold in the equality engine, to ensure that we
402
    // aren't processing a stale fact
403
723042
    std::vector<Node> expc = exp;
404
900998
    for (size_t i = 0; i < expc.size(); i++)
405
    {
406
1046511
      Node e = expc[i];
407
539477
      bool epol = e.getKind() != NOT;
408
1046511
      Node eatom = epol ? e : e[0];
409
1078954
      Trace("infer-manager")
410
539477
          << "...check " << eatom << " " << epol << std::endl;
411
539477
      if (eatom.getKind() == AND)
412
      {
413
32443
        Assert(epol);
414
219334
        for (const Node& ea : eatom)
415
        {
416
186891
          expc.push_back(ea);
417
        }
418
32443
        continue;
419
      }
420
507034
      else if (eatom.getKind() == EQUAL)
421
      {
422
214434
        Assert(d_ee->hasTerm(eatom[0]));
423
214434
        Assert(d_ee->hasTerm(eatom[1]));
424
214434
        Assert(!epol || d_ee->areEqual(eatom[0], eatom[1]));
425
214434
        Assert(epol || d_ee->areDisequal(eatom[0], eatom[1], false));
426
      }
427
      else
428
      {
429
292600
        Assert(d_ee->hasTerm(eatom));
430
292600
        Assert(d_ee->areEqual(eatom, NodeManager::currentNM()->mkConst(epol)));
431
      }
432
    }
433
  }
434
361521
  d_numCurrentFacts++;
435
  // Now, assert the fact. How to do so depends on whether proofs are enabled.
436
361521
  bool ret = false;
437
361521
  if (d_pfee == nullptr)
438
  {
439
344719
    Trace("infer-manager") << "...assert without proofs..." << std::endl;
440
344719
    if (atom.getKind() == kind::EQUAL)
441
    {
442
290546
      ret = d_ee->assertEquality(atom, pol, expn);
443
    }
444
    else
445
    {
446
54173
      ret = d_ee->assertPredicate(atom, pol, expn);
447
    }
448
    // Must reference count the equality and its explanation, which is not done
449
    // by the equality engine. Notice that we do *not* need to do this for
450
    // external assertions, which enter as facts in theory check. This is also
451
    // not done if we are asserting to the proof equality engine, which does
452
    // this caching itself within ProofEqEngine::assertFact.
453
344719
    d_keep.insert(atom);
454
344719
    d_keep.insert(expn);
455
  }
456
  else
457
  {
458
16802
    Assert(id != PfRule::UNKNOWN);
459
16802
    Trace("infer-manager") << "...assert with proofs..." << std::endl;
460
    // Note that we reconstruct the original literal lit here, since both the
461
    // original literal is needed for bookkeeping proofs. It is possible to
462
    // optimize this so that a few less nodes are created, but at the cost
463
    // of a more verbose interface to proof equality engine.
464
33604
    Node lit = pol ? Node(atom) : atom.notNode();
465
16802
    if (pg != nullptr)
466
    {
467
      // use the proof generator interface
468
15183
      ret = d_pfee->assertFact(lit, expn, pg);
469
    }
470
    else
471
    {
472
      // use the explict proof step interface
473
1619
      ret = d_pfee->assertFact(lit, id, expn, args);
474
    }
475
  }
476
  // call the notify fact method with isInternal = true
477
361521
  d_theory.notifyFact(atom, pol, expn, true);
478
723042
  Trace("infer-manager")
479
361521
      << "TheoryInferenceManager::finished assertInternalFact, ret=" << ret
480
361521
      << std::endl;
481
361521
  return ret;
482
}
483
484
43505
void TheoryInferenceManager::explain(TNode n, std::vector<TNode>& assumptions)
485
{
486
43505
  if (n.getKind() == kind::AND)
487
  {
488
    for (const Node& nc : n)
489
    {
490
      d_ee->explainLit(nc, assumptions);
491
    }
492
  }
493
  else
494
  {
495
43505
    d_ee->explainLit(n, assumptions);
496
  }
497
43505
}
498
499
Node TheoryInferenceManager::mkExplain(TNode n)
500
{
501
  std::vector<TNode> assumptions;
502
  explain(n, assumptions);
503
  return NodeManager::currentNM()->mkAnd(assumptions);
504
}
505
506
23260
Node TheoryInferenceManager::mkExplainPartial(
507
    const std::vector<Node>& exp, const std::vector<Node>& noExplain)
508
{
509
46520
  std::vector<TNode> assumps;
510
71084
  for (const Node& e : exp)
511
  {
512
52143
    if (std::find(noExplain.begin(), noExplain.end(), e) != noExplain.end())
513
    {
514
4319
      if (std::find(assumps.begin(), assumps.end(), e) == assumps.end())
515
      {
516
        // a non-explained literal
517
4319
        assumps.push_back(e);
518
      }
519
4319
      continue;
520
    }
521
    // otherwise, explain it
522
43505
    explain(e, assumps);
523
  }
524
46520
  return NodeManager::currentNM()->mkAnd(assumps);
525
}
526
527
uint32_t TheoryInferenceManager::numSentFacts() const
528
{
529
  return d_numCurrentFacts;
530
}
531
532
69813
bool TheoryInferenceManager::hasSentFact() const
533
{
534
69813
  return d_numCurrentFacts != 0;
535
}
536
537
1533256
bool TheoryInferenceManager::cacheLemma(TNode lem, LemmaProperty p)
538
{
539
3066512
  Node rewritten = Rewriter::rewrite(lem);
540
1533256
  if (d_lemmasSent.find(rewritten) != d_lemmasSent.end())
541
  {
542
1280344
    return false;
543
  }
544
252912
  d_lemmasSent.insert(rewritten);
545
252912
  return true;
546
}
547
548
13904
DecisionManager* TheoryInferenceManager::getDecisionManager()
549
{
550
13904
  return d_decManager;
551
}
552
553
31532
void TheoryInferenceManager::requirePhase(TNode n, bool pol)
554
{
555
31532
  return d_out.requirePhase(n, pol);
556
}
557
558
12
void TheoryInferenceManager::spendResource(Resource r)
559
{
560
12
  d_out.spendResource(r);
561
12
}
562
563
159598
void TheoryInferenceManager::safePoint(Resource r)
564
{
565
159598
  d_out.safePoint(r);
566
159598
}
567
568
2174
void TheoryInferenceManager::setIncomplete(IncompleteId id)
569
{
570
2174
  d_out.setIncomplete(id);
571
2174
}
572
573
961260
void TheoryInferenceManager::notifyInConflict()
574
{
575
961260
  d_theoryState.notifyInConflict();
576
961260
}
577
578
}  // namespace theory
579
29322
}  // namespace cvc5