summaryrefslogtreecommitdiffstats
path: root/src/sat/bsat/satSolver.h
blob: 226d8c7ad9bca7dc8ef8284cf0ef328c6a638fbf (plain)
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
/**************************************************************************************************
MiniSat -- Copyright (c) 2005, Niklas Sorensson
http://www.cs.chalmers.se/Cs/Research/FormalMethods/MiniSat/

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
associated documentation files (the "Software"), to deal in the Software without restriction,
including without limitation the rights to use, copy, modify, merge, publish, distribute,
sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or
substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT
NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT
OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
**************************************************************************************************/
// Modified to compile with MS Visual Studio 6.0 by Alan Mishchenko

#ifndef ABC__sat__bsat__satSolver_h
#define ABC__sat__bsat__satSolver_h


#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>

#include "satVec.h"
#include "satClause.h"
#include "sat/xsat/xsatFloat.h"

ABC_NAMESPACE_HEADER_START

//#define USE_FLOAT_ACTIVITY
//#define USE_FLOAT_ACTIVITY_NEW

//=================================================================================================
// Public interface:

struct sat_solver_t;
typedef struct sat_solver_t sat_solver;

extern sat_solver* sat_solver_new(void);
extern sat_solver* zsat_solver_new_seed(double seed);
extern void        sat_solver_delete(sat_solver* s);

extern int         sat_solver_addclause(sat_solver* s, lit* begin, lit* end);
extern int         sat_solver_clause_new(sat_solver* s, lit* begin, lit* end, int learnt);
extern int         sat_solver_simplify(sat_solver* s);
extern int         sat_solver_solve(sat_solver* s, lit* begin, lit* end, ABC_INT64_T nConfLimit, ABC_INT64_T nInsLimit, ABC_INT64_T nConfLimitGlobal, ABC_INT64_T nInsLimitGlobal);
extern int         sat_solver_solve_internal(sat_solver* s);
extern int         sat_solver_solve_lexsat(sat_solver* s, int * pLits, int nLits);
extern int         sat_solver_push(sat_solver* s, int p);
extern void        sat_solver_pop(sat_solver* s);
extern void        sat_solver_set_resource_limits(sat_solver* s, ABC_INT64_T nConfLimit, ABC_INT64_T nInsLimit, ABC_INT64_T nConfLimitGlobal, ABC_INT64_T nInsLimitGlobal);
extern void        sat_solver_restart( sat_solver* s );
extern void        zsat_solver_restart_seed( sat_solver* s, double seed );
extern void        sat_solver_rollback( sat_solver* s );

extern int         sat_solver_nvars(sat_solver* s);
extern int         sat_solver_nclauses(sat_solver* s);
extern int         sat_solver_nconflicts(sat_solver* s);
extern double      sat_solver_memory(sat_solver* s);
extern int         sat_solver_count_assigned(sat_solver* s);

extern void        sat_solver_setnvars(sat_solver* s,int n);
extern int         sat_solver_get_var_value(sat_solver* s, int v);
extern void        sat_solver_set_var_activity(sat_solver* s, int * pVars, int nVars);

extern void        Sat_SolverWriteDimacs( sat_solver * p, char * pFileName, lit* assumptionsBegin, lit* assumptionsEnd, int incrementVars );
extern void        Sat_SolverPrintStats( FILE * pFile, sat_solver * p );
extern int *       Sat_SolverGetModel( sat_solver * p, int * pVars, int nVars );
extern void        Sat_SolverDoubleClauses( sat_solver * p, int iVar );

// trace recording
extern void        Sat_SolverTraceStart( sat_solver * pSat, char * pName );
extern void        Sat_SolverTraceStop( sat_solver * pSat );
extern void        Sat_SolverTraceWrite( sat_solver * pSat, int * pBeg, int * pEnd, int fRoot );

// clause storage
extern void        sat_solver_store_alloc( sat_solver * s );
extern void        sat_solver_store_write( sat_solver * s, char * pFileName );
extern void        sat_solver_store_free( sat_solver * s );
extern void        sat_solver_store_mark_roots( sat_solver * s );
extern void        sat_solver_store_mark_clauses_a( sat_solver * s );
extern void *      sat_solver_store_release( sat_solver * s ); 

//=================================================================================================
// Solver representation:

//struct clause_t;
//typedef struct clause_t clause;

struct varinfo_t;
typedef struct varinfo_t varinfo;

struct sat_solver_t
{
    int         size;          // nof variables
    int         cap;           // size of varmaps
    int         qhead;         // Head index of queue.
    int         qtail;         // Tail index of queue.

    // clauses
    Sat_Mem_t   Mem;
    int         hLearnts;      // the first learnt clause
    int         hBinary;       // the special binary clause
    clause *    binary;
    veci*       wlists;        // watcher lists
    veci        act_clas;      // contain clause activities

    // rollback
    int         iVarPivot;     // the pivot for variables
    int         iTrailPivot;   // the pivot for trail
    int         hProofPivot;   // the pivot for proof records

    // activities
#ifdef USE_FLOAT_ACTIVITY
#ifdef USE_FLOAT_ACTIVITY_NEW
    xFloat_t    var_inc;       // Amount to bump next variable with.
    xFloat_t    var_inc2;      // Amount to bump next variable with.
    xFloat_t    var_decay;     // INVERSE decay factor for variable activity: stores 1/decay. 
    xFloat_t    cla_inc;       // Amount to bump next clause with.
    xFloat_t    cla_decay;     // INVERSE decay factor for clause activity: stores 1/decay.
    xFloat_t*   activity;      // A heuristic measurement of the activity of a variable.
    xFloat_t*   activity2;     // backup variable activity
#else
    double      var_inc;       // Amount to bump next variable with.
    double      var_inc2;      // Amount to bump next variable with.
    double      var_decay;     // INVERSE decay factor for variable activity: stores 1/decay. 
    float       cla_inc;       // Amount to bump next clause with.
    float       cla_decay;     // INVERSE decay factor for clause activity: stores 1/decay.
    double*     activity;      // A heuristic measurement of the activity of a variable.
    double*     activity2;     // A heuristic measurement of the activity of a variable.
#endif
#else
    int         var_inc;       // Amount to bump next variable with.
    int         var_inc2;      // Amount to bump next variable with.
    int         cla_inc;       // Amount to bump next clause with.
    unsigned*   activity;      // A heuristic measurement of the activity of a variable.
    unsigned*   activity2;     // backup variable activity
#endif
    char *      pFreqs;        // how many times this variable was assigned a value
    int         nVarUsed;

//    varinfo *   vi;            // variable information
    int*        levels;        //
    char*       assigns;       // Current values of variables.
    char*       polarity;      //
    char*       tags;          //
    char*       loads;         //

    int*        orderpos;      // Index in variable order.
    int*        reasons;       //
    lit*        trail;
    veci        tagged;        // (contains: var)
    veci        stack;         // (contains: var)

    veci        order;         // Variable order. (heap) (contains: var)
    veci        trail_lim;     // Separator indices for different decision levels in 'trail'. (contains: int)
//    veci        model;         // If problem is solved, this vector contains the model (contains: lbool).
    int *       model;         // If problem is solved, this vector contains the model (contains: lbool).
    veci        conf_final;    // If problem is unsatisfiable (possibly under assumptions),
                               // this vector represent the final conflict clause expressed in the assumptions.

    int         root_level;    // Level of first proper decision.
    int         simpdb_assigns;// Number of top-level assignments at last 'simplifyDB()'.
    int         simpdb_props;  // Number of propagations before next 'simplifyDB()'.
    double      random_seed;
    double      progress_estimate;
    int         verbosity;     // Verbosity level. 0=silent, 1=some progress report, 2=everything
    int         fVerbose;

    stats_t     stats;
    int         nLearntMax;    // max number of learned clauses
    int         nLearntStart;  // starting learned clause limit
    int         nLearntDelta;  // delta of learned clause limit
    int         nLearntRatio;  // ratio percentage of learned clauses
    int         nDBreduces;    // number of DB reductions

    ABC_INT64_T nConfLimit;    // external limit on the number of conflicts
    ABC_INT64_T nInsLimit;     // external limit on the number of implications
    abctime     nRuntimeLimit; // external limit on runtime

    veci        act_vars;      // variables whose activity has changed
    double*     factors;       // the activity factors
    int         nRestarts;     // the number of local restarts
    int         nCalls;        // the number of local restarts
    int         nCalls2;       // the number of local restarts
    veci        unit_lits;     // variables whose activity has changed
    veci        pivot_vars;    // pivot variables

    int         fSkipSimplify; // set to one to skip simplification of the clause database
    int         fNotUseRandom; // do not allow random decisions with a fixed probability
    int         fNoRestarts;   // disables periodic restarts

    int *       pGlobalVars;   // for experiments with global vars during interpolation
    // clause store
    void *      pStore;
    int         fSolved;

    // trace recording
    FILE *      pFile;
    int         nClauses;
    int         nRoots;

    veci        temp_clause;    // temporary storage for a CNF clause

    // CNF loading
    void *      pCnfMan;           // external CNF manager
    int(*pCnfFunc)(void * p, int); // external callback
};

static inline clause * clause_read( sat_solver * s, cla h )          
{ 
    return Sat_MemClauseHand( &s->Mem, h );      
}

static int sat_solver_var_value( sat_solver* s, int v )
{
    assert( v >= 0 && v < s->size );
    return (int)(s->model[v] == l_True);
}
static int sat_solver_var_literal( sat_solver* s, int v )
{
    assert( v >= 0 && v < s->size );
    return toLitCond( v, s->model[v] != l_True );
}
static void sat_solver_act_var_clear(sat_solver* s) 
{
    int i;
#ifdef USE_FLOAT_ACTIVITY
#ifdef USE_FLOAT_ACTIVITY_NEW
    for (i = 0; i < s->size; i++)
        s->activity[i] = xSat_FloatCreateConst1();
    s->var_inc = xSat_FloatCreateConst1();
#else
    for (i = 0; i < s->size; i++)
        s->activity[i] = 0;
    s->var_inc = 1;
#endif
#else
    for (i = 0; i < s->size; i++)
        s->activity[i] = 0;
    s->var_inc = (1 <<  5);
#endif
}
static void sat_solver_compress(sat_solver* s) 
{
    if ( s->qtail != s->qhead )
    {
        int RetValue = sat_solver_simplify(s);
        assert( RetValue != 0 );
        (void) RetValue;
    }
}
static void sat_solver_delete_p( sat_solver ** ps )
{
    if ( *ps )
        sat_solver_delete( *ps );
    *ps = NULL;
}
static void sat_solver_clean_polarity(sat_solver* s, int * pVars, int nVars )
{
    int i;
    for ( i = 0; i < nVars; i++ )
        s->polarity[pVars[i]] = 0;
}
static void sat_solver_set_polarity(sat_solver* s, int * pVars, int nVars )
{
    int i;
    for ( i = 0; i < s->size; i++ )
        s->polarity[i] = 0;
    for ( i = 0; i < nVars; i++ )
        s->polarity[pVars[i]] = 1;
}
static void sat_solver_set_literal_polarity(sat_solver* s, int * pLits, int nLits )
{
    int i;
    for ( i = 0; i < nLits; i++ )
        s->polarity[Abc_Lit2Var(pLits[i])] = !Abc_LitIsCompl(pLits[i]);
}

static int sat_solver_final(sat_solver* s, int ** ppArray)
{
    *ppArray = s->conf_final.ptr;
    return s->conf_final.size;
}

static abctime sat_solver_set_runtime_limit(sat_solver* s, abctime Limit)
{
    abctime nRuntimeLimit = s->nRuntimeLimit;
    s->nRuntimeLimit = Limit;
    return nRuntimeLimit;
}

static int sat_solver_set_random(sat_solver* s, int fNotUseRandom)
{
    int fNotUseRandomOld = s->fNotUseRandom;
    s->fNotUseRandom = fNotUseRandom;
    return fNotUseRandomOld;
}

static inline void sat_solver_bookmark(sat_solver* s)
{
    assert( s->qhead == s->qtail );
    s->iVarPivot    = s->size;
    s->iTrailPivot  = s->qhead;
    Sat_MemBookMark( &s->Mem );
    if ( s->activity2 )
    {
#ifdef USE_FLOAT_ACTIVITY
#ifdef USE_FLOAT_ACTIVITY_NEW
        s->var_inc2 = s->var_inc;
        memcpy( s->activity2, s->activity, sizeof(xFloat_t) * s->iVarPivot );
#else
        s->var_inc2 = s->var_inc;
        memcpy( s->activity2, s->activity, sizeof(double) * s->iVarPivot );
#endif
#else
        s->var_inc2 = s->var_inc;
        memcpy( s->activity2, s->activity, sizeof(unsigned) * s->iVarPivot );
#endif
    }
}
static inline void sat_solver_set_pivot_variables( sat_solver* s, int * pPivots, int nPivots )
{
    s->pivot_vars.cap = nPivots;
    s->pivot_vars.size = nPivots;
    s->pivot_vars.ptr = pPivots;
}
static inline int sat_solver_count_usedvars(sat_solver* s)
{
    int i, nVars = 0;
    for ( i = 0; i < s->size; i++ )
        if ( s->pFreqs[i] )
        {
            s->pFreqs[i] = 0;
            nVars++;
        }
    return nVars;
}

static inline int sat_solver_add_const( sat_solver * pSat, int iVar, int fCompl )
{
    lit Lits[1];
    int Cid;
    assert( iVar >= 0 );

    Lits[0] = toLitCond( iVar, fCompl );
    Cid = sat_solver_addclause( pSat, Lits, Lits + 1 );
    assert( Cid );
    return 1;
}
static inline int sat_solver_add_buffer( sat_solver * pSat, int iVarA, int iVarB, int fCompl )
{
    lit Lits[2];
    int Cid;
    assert( iVarA >= 0 && iVarB >= 0 );

    Lits[0] = toLitCond( iVarA, 0 );
    Lits[1] = toLitCond( iVarB, !fCompl );
    Cid = sat_solver_addclause( pSat, Lits, Lits + 2 );
    if ( Cid == 0 )
        return 0;
    assert( Cid );

    Lits[0] = toLitCond( iVarA, 1 );
    Lits[1] = toLitCond( iVarB, fCompl );
    Cid = sat_solver_addclause( pSat, Lits, Lits + 2 );
    if ( Cid == 0 )
        return 0;
    assert( Cid );
    return 2;
}
static inline int sat_solver_add_buffer_enable( sat_solver * pSat, int iVarA, int iVarB, int iVarEn, int fCompl )
{
    lit Lits[3];
    int Cid;
    assert( iVarA >= 0 && iVarB >= 0 && iVarEn >= 0 );

    Lits[0] = toLitCond( iVarA, 0 );
    Lits[1] = toLitCond( iVarB, !fCompl );
    Lits[2] = toLitCond( iVarEn, 1 );
    Cid = sat_solver_addclause( pSat, Lits, Lits + 3 );
    assert( Cid );

    Lits[0] = toLitCond( iVarA, 1 );
    Lits[1] = toLitCond( iVarB, fCompl );
    Lits[2] = toLitCond( iVarEn, 1 );
    Cid = sat_solver_addclause( pSat, Lits, Lits + 3 );
    assert( Cid );
    return 2;
}
static inline int sat_solver_add_and( sat_solver * pSat, int iVar, int iVar0, int iVar1, int fCompl0, int fCompl1, int fCompl )
{
    lit Lits[3];
    int Cid;

    Lits[0] = toLitCond( iVar, !fCompl );
    Lits[1] = toLitCond( iVar0, fCompl0 );
    Cid = sat_solver_addclause( pSat, Lits, Lits + 2 );
    assert( Cid );

    Lits[0] = toLitCond( iVar, !fCompl );
    Lits[1] = toLitCond( iVar1, fCompl1 );
    Cid = sat_solver_addclause( pSat, Lits, Lits + 2 );
    assert( Cid );

    Lits[0] = toLitCond( iVar, fCompl );
    Lits[1] = toLitCond( iVar0, !fCompl0 );
    Lits[2] = toLitCond( iVar1, !fCompl1 );
    Cid = sat_solver_addclause( pSat, Lits, Lits + 3 );
    assert( Cid );
    return 3;
}
static inline int sat_solver_add_xor( sat_solver * pSat, int iVarA, int iVarB, int iVarC, int fCompl )
{
    lit Lits[3];
    int Cid;
    assert( iVarA >= 0 && iVarB >= 0 && iVarC >= 0 );

    Lits[0] = toLitCond( iVarA, !fCompl );
    Lits[1] = toLitCond( iVarB, 1 );
    Lits[2] = toLitCond( iVarC, 1 );
    Cid = sat_solver_addclause( pSat, Lits, Lits + 3 );
    assert( Cid );

    Lits[0] = toLitCond( iVarA, !fCompl );
    Lits[1] = toLitCond( iVarB, 0 );
    Lits[2] = toLitCond( iVarC, 0 );
    Cid = sat_solver_addclause( pSat, Lits, Lits + 3 );
    assert( Cid );

    Lits[0] = toLitCond( iVarA, fCompl );
    Lits[1] = toLitCond( iVarB, 1 );
    Lits[2] = toLitCond( iVarC, 0 );
    Cid = sat_solver_addclause( pSat, Lits, Lits + 3 );
    assert( Cid );

    Lits[0] = toLitCond( iVarA, fCompl );
    Lits[1] = toLitCond( iVarB, 0 );
    Lits[2] = toLitCond( iVarC, 1 );
    Cid = sat_solver_addclause( pSat, Lits, Lits + 3 );
    assert( Cid );
    return 4;
}
static inline int sat_solver_add_mux( sat_solver * pSat, int iVarZ, int iVarC, int iVarT, int iVarE, int iComplC, int iComplT, int iComplE, int iComplZ )
{
    lit Lits[3];
    int Cid;
    assert( iVarC >= 0 && iVarT >= 0 && iVarE >= 0 && iVarZ >= 0 );

    Lits[0] = toLitCond( iVarC, 1 ^ iComplC );
    Lits[1] = toLitCond( iVarT, 1 ^ iComplT );
    Lits[2] = toLitCond( iVarZ, 0 );
    Cid = sat_solver_addclause( pSat, Lits, Lits + 3 );
    assert( Cid );

    Lits[0] = toLitCond( iVarC, 1 ^ iComplC );
    Lits[1] = toLitCond( iVarT, 0 ^ iComplT );
    Lits[2] = toLitCond( iVarZ, 1 ^ iComplZ );
    Cid = sat_solver_addclause( pSat, Lits, Lits + 3 );
    assert( Cid );

    Lits[0] = toLitCond( iVarC, 0 ^ iComplC );
    Lits[1] = toLitCond( iVarE, 1 ^ iComplE );
    Lits[2] = toLitCond( iVarZ, 0 ^ iComplZ );
    Cid = sat_solver_addclause( pSat, Lits, Lits + 3 );
    assert( Cid );

    Lits[0] = toLitCond( iVarC, 0 ^ iComplC );
    Lits[1] = toLitCond( iVarE, 0 ^ iComplE );
    Lits[2] = toLitCond( iVarZ, 1 ^ iComplZ );
    Cid = sat_solver_addclause( pSat, Lits, Lits + 3 );
    assert( Cid );

    if ( iVarT == iVarE )
        return 4;

    Lits[0] = toLitCond( iVarT, 0 ^ iComplT );
    Lits[1] = toLitCond( iVarE, 0 ^ iComplE );
    Lits[2] = toLitCond( iVarZ, 1 ^ iComplZ );
    Cid = sat_solver_addclause( pSat, Lits, Lits + 3 );
    assert( Cid );

    Lits[0] = toLitCond( iVarT, 1 ^ iComplT );
    Lits[1] = toLitCond( iVarE, 1 ^ iComplE );
    Lits[2] = toLitCond( iVarZ, 0 ^ iComplZ );
    Cid = sat_solver_addclause( pSat, Lits, Lits + 3 );
    assert( Cid );
    return 6;
}
static inline int sat_solver_add_mux41( sat_solver * pSat, int iVarZ, int iVarC0, int iVarC1, int iVarD0, int iVarD1, int iVarD2, int iVarD3 )
{
    lit Lits[4];
    int Cid;
    assert( iVarC0 >= 0 && iVarC1 >= 0 && iVarD0 >= 0 && iVarD1 >= 0 && iVarD2 >= 0 && iVarD3 >= 0 && iVarZ >= 0 );

    Lits[0] = toLitCond( iVarD0, 1 );
    Lits[1] = toLitCond( iVarC0, 0 );
    Lits[2] = toLitCond( iVarC1, 0 );
    Lits[3] = toLitCond( iVarZ,  0 );
    Cid = sat_solver_addclause( pSat, Lits, Lits + 4 );
    assert( Cid );

    Lits[0] = toLitCond( iVarD1, 1 );
    Lits[1] = toLitCond( iVarC0, 1 );
    Lits[2] = toLitCond( iVarC1, 0 );
    Lits[3] = toLitCond( iVarZ,  0 );
    Cid = sat_solver_addclause( pSat, Lits, Lits + 4 );
    assert( Cid );

    Lits[0] = toLitCond( iVarD2, 1 );
    Lits[1] = toLitCond( iVarC0, 0 );
    Lits[2] = toLitCond( iVarC1, 1 );
    Lits[3] = toLitCond( iVarZ,  0 );
    Cid = sat_solver_addclause( pSat, Lits, Lits + 4 );
    assert( Cid );

    Lits[0] = toLitCond( iVarD3, 1 );
    Lits[1] = toLitCond( iVarC0, 1 );
    Lits[2] = toLitCond( iVarC1, 1 );
    Lits[3] = toLitCond( iVarZ,  0 );
    Cid = sat_solver_addclause( pSat, Lits, Lits + 4 );
    assert( Cid );


    Lits[0] = toLitCond( iVarD0, 0 );
    Lits[1] = toLitCond( iVarC0, 0 );
    Lits[2] = toLitCond( iVarC1, 0 );
    Lits[3] = toLitCond( iVarZ,  1 );
    Cid = sat_solver_addclause( pSat, Lits, Lits + 4 );
    assert( Cid );

    Lits[0] = toLitCond( iVarD1, 0 );
    Lits[1] = toLitCond( iVarC0, 1 );
    Lits[2] = toLitCond( iVarC1, 0 );
    Lits[3] = toLitCond( iVarZ,  1 );
    Cid = sat_solver_addclause( pSat, Lits, Lits + 4 );
    assert( Cid );

    Lits[0] = toLitCond( iVarD2, 0 );
    Lits[1] = toLitCond( iVarC0, 0 );
    Lits[2] = toLitCond( iVarC1, 1 );
    Lits[3] = toLitCond( iVarZ,  1 );
    Cid = sat_solver_addclause( pSat, Lits, Lits + 4 );
    assert( Cid );

    Lits[0] = toLitCond( iVarD3, 0 );
    Lits[1] = toLitCond( iVarC0, 1 );
    Lits[2] = toLitCond( iVarC1, 1 );
    Lits[3] = toLitCond( iVarZ,  1 );
    Cid = sat_solver_addclause( pSat, Lits, Lits + 4 );
    assert( Cid );
    return 8;
}
static inline int sat_solver_add_xor_and( sat_solver * pSat, int iVarF, int iVarA, int iVarB, int iVarC )
{
    // F = (a (+) b) * c
    lit Lits[4];
    int Cid;
    assert( iVarF >= 0 && iVarA >= 0 && iVarB >= 0 && iVarC >= 0 );

    Lits[0] = toLitCond( iVarF, 1 );
    Lits[1] = toLitCond( iVarA, 1 );
    Lits[2] = toLitCond( iVarB, 1 );
    Cid = sat_solver_addclause( pSat, Lits, Lits + 3 );
    assert( Cid );

    Lits[0] = toLitCond( iVarF, 1 );
    Lits[1] = toLitCond( iVarA, 0 );
    Lits[2] = toLitCond( iVarB, 0 );
    Cid = sat_solver_addclause( pSat, Lits, Lits + 3 );
    assert( Cid );

    Lits[0] = toLitCond( iVarF, 1 );
    Lits[1] = toLitCond( iVarC, 0 );
    Cid = sat_solver_addclause( pSat, Lits, Lits + 2 );
    assert( Cid );

    Lits[0] = toLitCond( iVarF, 0 );
    Lits[1] = toLitCond( iVarA, 1 );
    Lits[2] = toLitCond( iVarB, 0 );
    Lits[3] = toLitCond( iVarC, 1 );
    Cid = sat_solver_addclause( pSat, Lits, Lits + 4 );
    assert( Cid );

    Lits[0] = toLitCond( iVarF, 0 );
    Lits[1] = toLitCond( iVarA, 0 );
    Lits[2] = toLitCond( iVarB, 1 );
    Lits[3] = toLitCond( iVarC, 1 );
    Cid = sat_solver_addclause( pSat, Lits, Lits + 4 );
    assert( Cid );
    return 5;
}
static inline int sat_solver_add_constraint( sat_solver * pSat, int iVar, int iVar2, int fCompl )
{
    lit Lits[2];
    int Cid;
    assert( iVar >= 0 );

    Lits[0] = toLitCond( iVar, fCompl );
    Lits[1] = toLitCond( iVar2, 0 );
    Cid = sat_solver_addclause( pSat, Lits, Lits + 2 );
    assert( Cid );

    Lits[0] = toLitCond( iVar, fCompl );
    Lits[1] = toLitCond( iVar2, 1 );
    Cid = sat_solver_addclause( pSat, Lits, Lits + 2 );
    assert( Cid );
    return 2;
}

static inline int sat_solver_add_half_sorter( sat_solver * pSat, int iVarA, int iVarB, int iVar0, int iVar1 )
{
    lit Lits[3];
    int Cid;

    Lits[0] = toLitCond( iVarA, 0 );
    Lits[1] = toLitCond( iVar0, 1 );
    Cid = sat_solver_addclause( pSat, Lits, Lits + 2 );
    assert( Cid );

    Lits[0] = toLitCond( iVarA, 0 );
    Lits[1] = toLitCond( iVar1, 1 );
    Cid = sat_solver_addclause( pSat, Lits, Lits + 2 );
    assert( Cid );

    Lits[0] = toLitCond( iVarB, 0 );
    Lits[1] = toLitCond( iVar0, 1 );
    Lits[2] = toLitCond( iVar1, 1 );
    Cid = sat_solver_addclause( pSat, Lits, Lits + 3 );
    assert( Cid );
    return 3;
}


ABC_NAMESPACE_HEADER_END

#endif