dtbasat.cc 22.4 KB
Newer Older
1
// -*- coding: utf-8 -*-
2
// Copyright (C) 2013, 2014 Laboratoire de Recherche et Développement
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
// de l'Epita.
//
// This file is part of Spot, a model checking library.
//
// Spot is free software; you can redistribute it and/or modify it
// under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 3 of the License, or
// (at your option) any later version.
//
// Spot is distributed in the hope that it will be useful, but WITHOUT
// ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
// or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
// License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

#include <iostream>
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
21
#include <fstream>
22
23
24
25
26
27
28
29
30
#include <sstream>
#include "dtbasat.hh"
#include "reachiter.hh"
#include <map>
#include <utility>
#include "scc.hh"
#include "tgba/bddprint.hh"
#include "ltlast/constant.hh"
#include "stats.hh"
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
31
#include "misc/satsolver.hh"
32
33
#include "misc/timer.hh"
#include "dotty.hh"
34

35
36
37
// If you set the SPOT_TMPKEEP environment variable the temporary
// file used to communicate with the sat solver will be left in
// the current directory.
38
//
39
40
41
42
// Additionally, if the following DEBUG macro is set to 1, the CNF
// file will be output with a comment before each clause, and an
// additional output file (dtba-sat.dbg) will be created with a list
// of all positive variables in the result and their meaning.
43
44
45
46

#define DEBUG 0
#if DEBUG
#define dout out << "c "
47
#define trace std::cerr
48
#else
49
50
#define dout while (0) std::cout
#define trace dout
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
#endif

namespace spot
{
  namespace
  {
    static bdd_dict* debug_dict = 0;

    struct transition
    {
      int src;
      bdd cond;
      int dst;

      transition(int src, bdd cond, int dst)
	: src(src), cond(cond), dst(dst)
      {
      }

      bool operator<(const transition& other) const
      {
	if (this->src < other.src)
	  return true;
	if (this->src > other.src)
	  return false;
	if (this->dst < other.dst)
	  return true;
	if (this->dst > other.dst)
	  return false;
	return this->cond.id() < other.cond.id();
      }

      bool operator==(const transition& other) const
      {
	return (this->src == other.src
		&& this->dst == other.dst
		&& this->cond.id() == other.cond.id());
      }
    };

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
    struct src_cond
    {
      int src;
      bdd cond;

      src_cond(int src, bdd cond)
	: src(src), cond(cond)
      {
      }

      bool operator<(const src_cond& other) const
      {
	if (this->src < other.src)
	  return true;
	if (this->src > other.src)
	  return false;
	return this->cond.id() < other.cond.id();
      }

      bool operator==(const src_cond& other) const
      {
	return (this->src == other.src
		&& this->cond.id() == other.cond.id());
      }
    };

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
    struct state_pair
    {
      int a;
      int b;

      state_pair(int a, int b)
	: a(a), b(b)
      {
      }

      bool operator<(const state_pair& other) const
      {
	if (this->a < other.a)
	  return true;
	if (this->a > other.a)
	  return false;
	if (this->b < other.b)
	  return true;
	if (this->b > other.b)
	  return false;
	return false;
      }
    };

    struct path
    {
      int src_cand;
      int src_ref;
      int dst_cand;
      int dst_ref;

      path(int src_cand, int src_ref,
	   int dst_cand, int dst_ref)
	: src_cand(src_cand), src_ref(src_ref),
	  dst_cand(dst_cand), dst_ref(dst_ref)
      {
      }

      bool operator<(const path& other) const
      {
	if (this->src_cand < other.src_cand)
	  return true;
	if (this->src_cand > other.src_cand)
	  return false;
	if (this->src_ref < other.src_ref)
	  return true;
	if (this->src_ref > other.src_ref)
	  return false;
	if (this->dst_cand < other.dst_cand)
	  return true;
	if (this->dst_cand > other.dst_cand)
	  return false;
	if (this->dst_ref < other.dst_ref)
	  return true;
	if (this->dst_ref > other.dst_ref)
	  return false;
	return false;
      }

    };

    std::ostream& operator<<(std::ostream& os, const state_pair& p)
    {
      os << "<" << p.a << "," << p.b << ">";
      return os;
    }

    std::ostream& operator<<(std::ostream& os, const transition& t)
    {
      os << "<" << t.src << ","
	 << bdd_format_formula(debug_dict, t.cond)
	 << "," << t.dst << ">";
      return os;
    }

    std::ostream& operator<<(std::ostream& os, const path& p)
    {
      os << "<"
	 << p.src_cand << ","
	 << p.src_ref << ","
	 << p.dst_cand << ","
	 << p.dst_ref << ">";
      return os;
    }

    struct dict
    {
      typedef std::map<transition, int> trans_map;
      trans_map transid;
      trans_map transacc;
      typedef std::map<int, transition> rev_map;
      rev_map revtransid;
      rev_map revtransacc;

      std::map<state_pair, int> prodid;
      std::map<path, int> pathid_ref;
      std::map<path, int> pathid_cand;
      int nvars;
      typedef Sgi::hash_map<const state*, int,
			    state_ptr_hash, state_ptr_equal> state_map;
      typedef Sgi::hash_map<int, const state*> int_map;
      state_map state_to_int;
      int_map int_to_state;
      int cand_size;

      ~dict()
      {
	state_map::const_iterator s = state_to_int.begin();
	while (s != state_to_int.end())
	  // Always advance the iterator before deleting the key.
	  s++->first->destroy();
      }
    };


    class filler_dfs: public tgba_reachable_iterator_depth_first
    {
    protected:
      dict& d;
      int size_;
      bdd ap_;
238
      bool state_based_;
239
      scc_map& sm_;
240
    public:
241
242
      filler_dfs(const tgba* aut, dict& d, bdd ap, bool state_based,
		 scc_map& sm)
243
	: tgba_reachable_iterator_depth_first(aut), d(d), ap_(ap),
244
	  state_based_(state_based), sm_(sm)
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
      {
	d.nvars = 0;
      }

      int size()
      {
	return size_;
      }

      void end()
      {
	size_ = seen.size();

	if (d.cand_size == -1)
	  d.cand_size = size_ - 1;

261
	// Reverse the "seen" map.  States are labeled from 1 to size_.
262
263
	for (dict::state_map::const_iterator i2 = seen.begin();
	     i2 != seen.end(); ++i2)
264
265
266
	  d.int_to_state[i2->second] = i2->first;

	for (int i = 1; i <= size_; ++i)
267
	  {
268
269
	    unsigned i_scc = sm_.scc_of_state(d.int_to_state[i]);

270
	    bool is_trivial = sm_.trivial(i_scc);
271

272
273
274
275
	    for (int j = 1; j <= d.cand_size; ++j)
	      {
		d.prodid[state_pair(j, i)] = ++d.nvars;

276
277
		// skip trivial SCCs
		if (is_trivial)
278
		  continue;
279

280
		for (int k = 1; k <= size_; ++k)
281
		  {
282
		    if (sm_.scc_of_state(d.int_to_state[k]) != i_scc)
283
284
		      continue;
		    for (int l = 1; l <= d.cand_size; ++l)
285
		    {
286
287
		      if (i == k && j == l)
			continue;
288
289
290
291
		      path p(j, i, l, k);
		      d.pathid_ref[p] = ++d.nvars;
		      d.pathid_cand[p] = ++d.nvars;
		    }
292
		  }
293
294
295
296
297
298
	      }
	  }

	std::swap(d.state_to_int, seen);

	for (int i = 1; i <= d.cand_size; ++i)
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
	  {
	    int transacc = -1;
	    if (state_based_)
	      // All outgoing transitions use the same acceptance variable.
	      transacc = ++d.nvars;

	    for (int j = 1; j <= d.cand_size; ++j)
	      {
		bdd all = bddtrue;
		while (all != bddfalse)
		  {
		    bdd one = bdd_satoneset(all, ap_, bddfalse);
		    all -= one;

		    transition t(i, one, j);
		    d.transid[t] = ++d.nvars;
		    d.revtransid.insert(dict::rev_map::value_type(d.nvars, t));
		    int ta = d.transacc[t] =
		      state_based_ ? transacc : ++d.nvars;
		    d.revtransacc.insert(dict::rev_map::value_type(ta, t));
		  }
	      }
	  }
322
323
324
      }
    };

325
326
    typedef std::pair<int, int> sat_stats;

327
    static
328
329
    sat_stats dtba_to_sat(std::ostream& out, const tgba* ref,
			  dict& d, bool state_based)
330
    {
331
      clause_counter nclauses;
332
333
334
335
336
337
      int ref_size = 0;

      scc_map sm(ref);
      sm.build_map();
      bdd ap = sm.aprec_set_of(sm.initial());

338
339
340
341
342
343
344
345
346
347
348
349
      // Count the number of atomic propositions
      int nap = 0;
      {
	bdd cur = ap;
	while (cur != bddtrue)
	  {
	    ++nap;
	    cur = bdd_high(cur);
	  }
	nap = 1 << nap;
      }

350
351
      // Number all the SAT variable we may need.
      {
352
	filler_dfs f(ref, d, ap, state_based, sm);
353
354
355
356
357
358
359
360
	f.run();
	ref_size = f.size();
      }

      // empty automaton is impossible
      if (d.cand_size == 0)
	{
	  out << "p cnf 1 2\n-1 0\n1 0\n";
361
	  return std::make_pair(1, 2);
362
363
364
365
366
367
368
	}

      // An empty line for the header
      out << "                                                 \n";

#if DEBUG
      debug_dict = ref->get_dict();
369
370
      dout << "ref_size: " << ref_size << "\n";
      dout << "cand_size: " << d.cand_size << "\n";
371
372
#endif

373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
      dout << "symmetry-breaking clauses\n";
      int j = 0;
      bdd all = bddtrue;
      while (all != bddfalse)
 	{
 	  bdd s = bdd_satoneset(all, ap, bddfalse);
 	  all -= s;
 	  for (int i = 1; i < d.cand_size; ++i)
 	    for (int k = (i - 1) * nap + j + 3; k <= d.cand_size; ++k)
	      {
		transition t(i, s, k);
		int ti = d.transid[t];
		dout << "¬" << t << "\n";
		out << -ti << " 0\n";
		++nclauses;
	      }
 	  ++j;
 	}
391
      if (!nclauses.nb_clauses())
392
 	dout << "(none)\n";
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
      dout << "(1) the candidate automaton is complete\n";
      for (int q1 = 1; q1 <= d.cand_size; ++q1)
	{
	  bdd all = bddtrue;
	  while (all != bddfalse)
	    {
	      bdd s = bdd_satoneset(all, ap, bddfalse);
	      all -= s;

#if DEBUG
	      dout;
	      for (int q2 = 1; q2 <= d.cand_size; q2++)
		{
		  transition t(q1, s, q2);
		  out << t << "δ";
		  if (q2 != d.cand_size)
		    out << " ∨ ";
		}
	      out << "\n";
#endif

	      for (int q2 = 1; q2 <= d.cand_size; q2++)
		{
		  transition t(q1, s, q2);
		  int ti = d.transid[t];

		  out << ti << " ";
		}
	      out << "0\n";

	      ++nclauses;
	    }
	}

      dout << "(2) the initial state is reachable\n";
      dout << state_pair(1, 1) << "\n";
      out << d.prodid[state_pair(1, 1)] << " 0\n";
      ++nclauses;

      for (std::map<state_pair, int>::const_iterator pit = d.prodid.begin();
	   pit != d.prodid.end(); ++pit)
	{
	  int q1 = pit->first.a;
	  int q1p = pit->first.b;

	  dout << "(3) augmenting paths based on Cand[" << q1
	       << "] and Ref[" << q1p << "]\n";
	  tgba_succ_iterator* it = ref->succ_iter(d.int_to_state[q1p]);
	  for (it->first(); !it->done(); it->next())
	    {
	      const state* dps = it->current_state();
	      int dp = d.state_to_int[dps];
	      dps->destroy();

	      bdd all = it->current_condition();
	      while (all != bddfalse)
		{
		  bdd s = bdd_satoneset(all, ap, bddfalse);
		  all -= s;

		  for (int q2 = 1; q2 <= d.cand_size; q2++)
		    {
		      transition t(q1, s, q2);
		      int ti = d.transid[t];

		      state_pair p2(q2, dp);
		      int succ = d.prodid[p2];

462
463
464
		      if (pit->second == succ)
			continue;

465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
		      dout << pit->first << " ∧ " << t << "δ → " << p2 << "\n";
		      out << -pit->second << " " << -ti << " "
			  << succ << " 0\n";
		      ++nclauses;
		    }
		}
	    }
	  delete it;
	}

      bdd all_acc = ref->all_acceptance_conditions();

      // construction of contraints (4,5) : all loops in the product
      // where no accepting run is detected in the ref. automaton,
      // must also be marked as not accepting in the cand. automaton
480
481
482
      for (int q1p = 1; q1p <= ref_size; ++q1p)
	{
	  unsigned q1p_scc = sm.scc_of_state(d.int_to_state[q1p]);
483
484
	  if (sm.trivial(q1p_scc))
	    continue;
485
486
487
488
489
490
	  for (int q2p = 1; q2p <= ref_size; ++q2p)
	    {
	      // We are only interested in transition that can form a
	      // cycle, so they must belong to the same SCC.
	      if (sm.scc_of_state(d.int_to_state[q2p]) != q1p_scc)
		continue;
491
492
493
494
	      for (int q1 = 1; q1 <= d.cand_size; ++q1)
		for (int q2 = 1; q2 <= d.cand_size; ++q2)
		  {
		    path p1(q1, q1p, q2, q2p);
495

496
497
		    dout << "(4&5) matching paths from reference based on "
			 << p1 << "\n";
498

499
500
501
502
503
		    int pid1;
		    if (q1 == q2 && q1p == q2p)
		      pid1 = d.prodid[state_pair(q1, q1p)];
		    else
		      pid1 = d.pathid_ref[p1];
504

505
506
507
508
509
510
511
		    tgba_succ_iterator* it =
		      ref->succ_iter(d.int_to_state[q2p]);
		    for (it->first(); !it->done(); it->next())
		      {
			const state* dps = it->current_state();
			// Skip destinations not in the SCC.
			if (sm.scc_of_state(dps) != q1p_scc)
512
513
			  {
			    dps->destroy();
514
515
516
517
			    continue;
			  }
			int dp = d.state_to_int[dps];
			dps->destroy();
518

519
520
521
522
523
			if (it->current_acceptance_conditions() == all_acc)
			  continue;
			for (int q3 = 1; q3 <= d.cand_size; ++q3)
			  {
			    if (dp == q1p && q3 == q1) // (4) looping
524
			      {
525
526
				bdd all = it->current_condition();
				while (all != bddfalse)
527
				  {
528
529
530
531
532
533
534
535
536
537
538
539
540
				    bdd s = bdd_satoneset(all, ap, bddfalse);
				    all -= s;

				    transition t(q2, s, q1);
				    int ti = d.transid[t];
				    int ta = d.transacc[t];

				    dout << p1 << "R ∧ " << t << "δ → ¬" << t
					 << "F\n";
				    out << -pid1 << " " << -ti << " "
					<< -ta << " 0\n";
				    ++nclauses;
				  }
541
542


543
544
545
546
547
			      }
			    else // (5) not looping
			      {
				path p2 = path(q1, q1p, q3, dp);
				int pid2 = d.pathid_ref[p2];
548

549
550
				if (pid1 == pid2)
				  continue;
551

552
553
				bdd all = it->current_condition();
				while (all != bddfalse)
554
				  {
555
556
557
558
559
560
561
562
563
564
565
				    bdd s = bdd_satoneset(all, ap, bddfalse);
				    all -= s;

				    transition t(q2, s, q3);
				    int ti = d.transid[t];

				    dout << p1 << "R ∧ " << t << "δ → " << p2
					 << "R\n";
				    out << -pid1 << " " << -ti << " "
					<< pid2 << " 0\n";
				    ++nclauses;
566
567
568
569
				  }
			      }
			  }
		      }
570
571
		    delete it;
		  }
572
573
	    }
	}
574
575
576
      // construction of contraints (6,7): all loops in the product
      // where accepting run is detected in the ref. automaton, must
      // also be marked as accepting in the candidate.
577
578
579
      for (int q1p = 1; q1p <= ref_size; ++q1p)
	{
	  unsigned q1p_scc = sm.scc_of_state(d.int_to_state[q1p]);
580
581
	  if (sm.trivial(q1p_scc))
	    continue;
582
583
584
585
586
587
588
589
590
591
592
593
	  for (int q2p = 1; q2p <= ref_size; ++q2p)
	    {
	      // We are only interested in transition that can form a
	      // cycle, so they must belong to the same SCC.
	      if (sm.scc_of_state(d.int_to_state[q2p]) != q1p_scc)
		continue;
	      for (int q1 = 1; q1 <= d.cand_size; ++q1)
		for (int q2 = 1; q2 <= d.cand_size; ++q2)
		  {
		    path p1(q1, q1p, q2, q2p);
		    dout << "(6&7) matching paths from candidate based on "
			 << p1 << "\n";
594
595
596
597
598
599

		    int pid1;
		    if (q1 == q2 && q1p == q2p)
		      pid1 = d.prodid[state_pair(q1, q1p)];
		    else
		      pid1 = d.pathid_cand[p1];
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

		    tgba_succ_iterator* it =
		      ref->succ_iter(d.int_to_state[q2p]);
		    for (it->first(); !it->done(); it->next())
		      {
			const state* dps = it->current_state();
			// Skip destinations not in the SCC.
			if (sm.scc_of_state(dps) != q1p_scc)
			  {
			    dps->destroy();
			    continue;
			  }
			int dp = d.state_to_int[dps];
			dps->destroy();
			for (int q3 = 1; q3 <= d.cand_size; q3++)
			  {
			    if (dp == q1p && q3 == q1) // (6) looping
			      {
				// We only care about the looping case if
				// it is accepting in the reference.
				if (it->current_acceptance_conditions()
				    != all_acc)
				  continue;
				bdd all = it->current_condition();
				while (all != bddfalse)
				  {
				    bdd s = bdd_satoneset(all, ap, bddfalse);
				    all -= s;

				    transition t(q2, s, q1);
				    int ti = d.transid[t];
				    int ta = d.transacc[t];

				    dout << p1 << "C ∧ " << t << "δ → " << t
					 << "F\n";
				    out << -pid1 << " " << -ti << " " << ta
					<< " 0\n";
				    ++nclauses;
				  }
			      }
			    else // (7) no loop
			      {
				path p2 = path(q1, q1p, q3, dp);
				int pid2 = d.pathid_cand[p2];

				if (pid1 == pid2)
				  continue;

				bdd all = it->current_condition();
				while (all != bddfalse)
				  {
				    bdd s = bdd_satoneset(all, ap, bddfalse);
				    all -= s;

				    transition t(q2, s, q3);
				    int ti = d.transid[t];
				    int ta = d.transacc[t];

				    dout << p1 << "C ∧ " << t << "δ ∧ ¬"
					 << t << "F → " << p2 << "C\n";

				    out << -pid1 << " " << -ti << " "
					<< ta << " " << pid2 << " 0\n";
				    ++nclauses;
				  }
			      }
			  }
		      }
		    delete it;
		  }
	    }
	}
672
      out.seekp(0);
673
      out << "p cnf " << d.nvars << " " << nclauses.nb_clauses();
674
      return std::make_pair(d.nvars, nclauses.nb_clauses());
675
676
677
    }

    static tgba_explicit_number*
678
679
    sat_build(const satsolver::solution& solution, dict& satdict,
	      const tgba* aut, bool state_based)
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
    {
      bdd_dict* autdict = aut->get_dict();
      tgba_explicit_number* a = new tgba_explicit_number(autdict);
      autdict->register_all_variables_of(aut, a);

      const ltl::formula* t = ltl::constant::true_instance();
      bdd acc = bdd_ithvar(autdict->register_acceptance_variable(t, a));
      a->set_acceptance_conditions(acc);

      for (int s = 1; s < satdict.cand_size; ++s)
	a->add_state(s);

      state_explicit_number::transition* last_aut_trans = 0;
      const transition* last_sat_trans = 0;

#if DEBUG
      std::fstream out("dtba-sat.dbg",
		       std::ios_base::trunc | std::ios_base::out);
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
698
      out.exceptions(std::ifstream::failbit | std::ifstream::badbit);
699
700
701
702
      std::set<int> positive;
#endif

      dout << "--- transition variables ---\n";
703
      std::set<int> acc_states;
704
      std::set<src_cond> seen_trans;
705
      for (satsolver::solution::const_iterator i = solution.begin();
706
	   i != solution.end(); ++i)
707
	{
708
	  int v = *i;
709
710
711
712
713
714
715
716
717
718
719
720

	  if (v < 0)  // FIXME: maybe we can have (v < NNN)?
	    continue;

#if DEBUG
	  positive.insert(v);
#endif

	  dict::rev_map::const_iterator t = satdict.revtransid.find(v);

	  if (t != satdict.revtransid.end())
	    {
721
722
723
724
725
726
727
728
	      // Skip (s,l,d2) if we have already seen some (s,l,d1).
	      if (seen_trans.insert(src_cond(t->second.src,
					     t->second.cond)).second)
		{
		  last_aut_trans = a->create_transition(t->second.src,
							t->second.dst);
		  last_aut_trans->condition = t->second.cond;
		  last_sat_trans = &t->second;
729

730
		  dout << v << "\t" << t->second << \n";
731

732
733
734
735
736
		  // Mark the transition as accepting if the source is.
		  if (state_based
		      && acc_states.find(t->second.src) != acc_states.end())
		    last_aut_trans->acceptance_conditions = acc;
		}
737
738
739
740
741
742
743
744
	    }
	  else
	    {
	      t = satdict.revtransacc.find(v);
	      if (t != satdict.revtransacc.end())
		{
		  dout << v << "\t" << t->second << "F\n";
		  if (last_sat_trans && t->second == *last_sat_trans)
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
		    {
		      assert(!state_based);
		      // This assumes that the SAT solvers output
		      // variables in increasing order.
		      last_aut_trans->acceptance_conditions = acc;
		    }
		  else if (state_based)
		    {
		      // Accepting translations actually correspond to
		      // states and are announced before listing
		      // outgoing transitions.  Again, this assumes
		      // that the SAT solvers output variables in
		      // increasing order.
		      acc_states.insert(t->second.src);
		    }
760
761
762
763
764
765
766
767
768
		}
	    }
	}
#if DEBUG
      dout << "--- state_pair variables ---\n";
      for (std::map<state_pair, int>::const_iterator pit =
	     satdict.prodid.begin(); pit != satdict.prodid.end(); ++pit)
	if (positive.find(pit->second) != positive.end())
	  dout << pit->second << "\t" << pit->first << "\n";
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
769
770
	else
	  dout << -pit->second << "\t¬" << pit->first << "C\n";
771
772
773
774
775
776
777

      dout << "--- pathid_cand variables ---\n";
      for (std::map<path, int>::const_iterator pit =
	     satdict.pathid_cand.begin();
	   pit != satdict.pathid_cand.end(); ++pit)
	if (positive.find(pit->second) != positive.end())
	  dout << pit->second << "\t" << pit->first << "C\n";
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
778
779
780
	else
	  dout << -pit->second << "\t¬" << pit->first << "C\n";

781
782
783
784
785
786
787

      dout << "--- pathid_ref variables ---\n";
      for (std::map<path, int>::const_iterator pit =
	     satdict.pathid_ref.begin();
	   pit != satdict.pathid_ref.end(); ++pit)
	if (positive.find(pit->second) != positive.end())
	  dout << pit->second << "\t" << pit->first << "R\n";
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
788
789
790
791
792
793
794
795
796
797
798
799
	else
	  dout << -pit->second << "\t¬" << pit->first << "C\n";

      dout << "--- pathcand variables ---\n";
      for (std::map<state_pair, int>::const_iterator pit =
	     satdict.pathcand.begin();
	   pit != satdict.pathcand.end(); ++pit)
	if (positive.find(pit->second) != positive.end())
	  dout << pit->second << "\t" << pit->first << "C\n";
	else
	  dout << -pit->second << "\t¬" << pit->first << "C\n";

800
801
802
803
804
805
806
807
#endif

      a->merge_transitions();
      return a;
    }
  }

  tgba_explicit_number*
808
809
  dtba_sat_synthetize(const tgba* a, int target_state_number,
		      bool state_based)
810
  {
811
812
    if (target_state_number == 0)
      return 0;
813
814
    trace << "dtba_sat_synthetize(..., states = " << target_state_number
	  << ", state_based = " << state_based << ")\n";
815
816
    dict d;
    d.cand_size = target_state_number;
817

818
819
    satsolver solver;
    satsolver::solution_pair solution;
820

821
822
823
824
825
    timer_map t;
    t.start("encode");
    sat_stats s = dtba_to_sat(solver(), a, d, state_based);
    t.stop("encode");
    t.start("solve");
826
    solution = solver.get_solution();
827
    t.stop("solve");
828
829

    tgba_explicit_number* res = 0;
830
831
    if (!solution.second.empty())
      res = sat_build(solution.second, d, a, state_based);
832

833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
    static const char* log = getenv("SPOT_SATLOG");
    if (log)
      {
	std::fstream out(log,
			 std::ios_base::app | std::ios_base::out);
	out.exceptions(std::ifstream::failbit | std::ifstream::badbit);
	const timer& te = t.timer("encode");
	const timer& ts = t.timer("solve");
	out << target_state_number << ',';
	if (res)
	  {
	    tgba_sub_statistics st = sub_stats_reachable(res);
	    out << st.states << ',' << st.transitions
		<< ',' << st.sub_transitions;
	  }
	else
	  {
	    out << ",,";
	  }
	out << ','
	    << s.first << ',' << s.second << ','
	    << te.utime() << ',' << te.stime() << ','
	    << ts.utime() << ',' << ts.stime() << '\n';
      }
    static const char* show = getenv("SPOT_SATSHOW");
    if (show && res)
      dotty_reachable(std::cout, res);

861
862
863
864
865
866
867
868
869
870
871
    trace << "dtba_sat_synthetize(...) = " << res << "\n";
    return res;
  }

  tgba_explicit_number*
  dtba_sat_minimize(const tgba* a, bool state_based)
  {
    int n_states = stats_reachable(a).states;

    tgba_explicit_number* prev = 0;
    for (;;)
872
      {
873
874
875
876
	tgba_explicit_number* next =
	  dtba_sat_synthetize(prev ? prev : a, --n_states, state_based);
	if (next == 0)
	  break;
877
878
879
	else
	  n_states = stats_reachable(next).states;

880
881
	delete prev;
	prev = next;
882
      }
883
884
    return prev;
  }
885

886
887
888
889
890
891
892
893
  tgba_explicit_number*
  dtba_sat_minimize_dichotomy(const tgba* a, bool state_based)
  {
    int max_states = stats_reachable(a).states - 1;
    int min_states = 1;

    tgba_explicit_number* prev = 0;
    while (min_states <= max_states)
894
      {
895
896
897
898
	int target = (max_states + min_states) / 2;
	tgba_explicit_number* next =
	  dtba_sat_synthetize(prev ? prev : a, target, state_based);
	if (next == 0)
899
	  {
900
901
902
903
904
905
	    min_states = target + 1;
	  }
	else
	  {
	    delete prev;
	    prev = next;
906
	    max_states = stats_reachable(next).states - 1;
907
908
	  }
      }
909
    return prev;
910
911
  }
}