text: #pragma clang diagnostic push
  #pragma clang diagnostic ignored "-Wconversion"
  #pragma clang diagnostic ignored "-Wconditional-uninitialized"
  
  // Don't use NDEBUG in picosat
  #define DEBUG_PERFORMANCE
  #ifdef DEBUG_PERFORMANCE
  #ifdef NDEBUG
  #define NDEBUG_TMP
  #undef NDEBUG
  #endif
  #endif
  
  /****************************************************************************
  Copyright (c) 2006 - 2015, Armin Biere, Johannes Kepler University.
  
  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.
  ****************************************************************************/
  
  #include <stdlib.h>
  #include <stdio.h>
  #include <string.h>
  #include <assert.h>
  #include <limits.h>
  #include <ctype.h>
  #include <stdarg.h>
  #include <stdint.h>
  
  #include "picosat.h"
  
  /* By default code for 'all different constraints' is disabled, since 'NADC'
   * is defined.
   */
  #define NADC
  
  /* By default we enable failed literals, since 'NFL' is undefined.
   *
  #define NFL
   */
  
  /* By default we 'detach satisfied (large) clauses', e.g. NDSC undefined.
   *
  #define NDSC
   */
  
  /* Do not use luby restart schedule instead of inner/outer.
   *
  #define NLUBY
   */
  
  /* Enabling this define, will use gnuplot to visualize how the scores evolve.
   *
  #define VISCORES 
   */
  #ifdef VISCORES
  // #define WRITEGIF		/* ... to generate a video */
  #endif
  
  #ifdef VISCORES
  #ifndef WRITEGIF
  #include <unistd.h>		/* for 'usleep' */
  #endif
  #endif
  
  #ifdef RCODE
  #include <R.h>
  #endif
  
  #define MINRESTART	100	/* minimum restart interval */
  #define MAXRESTART	1000000 /* maximum restart interval */
  #define RDECIDE		1000	/* interval of random decisions */
  #define FRESTART	110	/* restart increase factor in percent */
  #define FREDUCE		110	/* reduce increase factor in percent  */
  #define FREDADJ		121	/* reduce increase adjustment factor */
  #define MAXCILS		10	/* maximal number of unrecycled internals */
  #define FFLIPPED	10000	/* flipped reduce factor */
  #define FFLIPPEDPREC	10000000/* flipped reduce factor precision */
  #define INTERRUPTLIM	1024	/* check interrupt after that many decisions */
  
  #ifndef TRACE
  #define NO_BINARY_CLAUSES	/* store binary clauses more compactly */
  #endif
  
  /* For debugging purposes you may want to define 'LOGGING', which actually
   * can be enforced by using './configure.sh --log'.
   */
  #ifdef LOGGING
  #define LOG(code) do { code; } while (0)
  #else
  #define LOG(code) do { } while (0)
  #endif
  #define NOLOG(code) do { } while (0)		/* log exception */
  #define ONLYLOG(code) do { code; } while (0)	/* force logging */
  
  #define FALSE ((Val)-1)
  #define UNDEF ((Val)0)
  #define TRUE ((Val)1)
  
  #define COMPACT_TRACECHECK_TRACE_FMT 0
  #define EXTENDED_TRACECHECK_TRACE_FMT 1
  #define RUP_TRACE_FMT 2
  
  #define NEWN(p,n) do { (p) = new (ps, sizeof (*(p)) * (n)); } while (0)
  #define CLRN(p,n) do { memset ((p), 0, sizeof (*(p)) * (n)); } while (0)
  #define CLR(p) CLRN(p,1)
  #define DELETEN(p,n) \
    do { delete (ps, p, sizeof (*(p)) * (n)); (p) = 0; } while (0)
  
  #define RESIZEN(p,old_num,new_num) \
    do { \
      size_t old_size = sizeof (*(p)) * (old_num); \
      size_t new_size = sizeof (*(p)) * (new_num); \
      (p) = resize (ps, (p), old_size, new_size) ; \
    } while (0)
  
  #define ENLARGE(start,head,end) \
    do { \
      unsigned old_num = (ptrdiff_t)((end) - (start)); \
      size_t new_num = old_num ? (2 * old_num) : 1; \
      unsigned count = (head) - (start); \
      assert ((start) <= (end)); \
      RESIZEN((start),old_num,new_num); \
      (head) = (start) + count; \
      (end) = (start) + new_num; \
    } while (0)
  
  #define NOTLIT(l) (ps->lits + (1 ^ ((l) - ps->lits)))
  
  #define LIT2IDX(l) ((ptrdiff_t)((l) - ps->lits) / 2)
  #define LIT2IMPLS(l) (ps->impls + (ptrdiff_t)((l) - ps->lits))
  #define LIT2INT(l) ((int)(LIT2SGN(l) * LIT2IDX(l)))
  #define LIT2SGN(l) (((ptrdiff_t)((l) - ps->lits) & 1) ? -1 : 1)
  #define LIT2VAR(l) (ps->vars + LIT2IDX(l))
  #define LIT2HTPS(l) (ps->htps + (ptrdiff_t)((l) - ps->lits))
  #define LIT2JWH(l) (ps->jwh + ((l) - ps->lits))
  
  #ifndef NDSC
  #define LIT2DHTPS(l) (ps->dhtps + (ptrdiff_t)((l) - ps->lits))
  #endif
  
  #ifdef NO_BINARY_CLAUSES
  typedef uintptr_t Wrd;
  #define ISLITREASON(C) (1&(Wrd)C)
  #define LIT2REASON(L) \
    (assert (L->val==TRUE), ((Cls*)(1 + (2*(L - ps->lits)))))
  #define REASON2LIT(C) ((Lit*)(ps->lits + ((Wrd)C)/2))
  #endif
  
  #define ENDOFCLS(c) ((void*)((Lit**)(c)->lits + (c)->size))
  
  #define SOC ((ps->oclauses == ps->ohead) ? ps->lclauses : ps->oclauses)
  #define EOC (ps->lhead)
  #define NXC(p) (((p) + 1 == ps->ohead) ? ps->lclauses : (p) + 1)
  
  #define OIDX2IDX(idx) (2 * ((idx) + 1))
  #define LIDX2IDX(idx) (2 * (idx) + 1)
  
  #define ISLIDX(idx) ((idx)&1)
  
  #define IDX2OIDX(idx) (assert(!ISLIDX(idx)), (idx)/2 - 1)
  #define IDX2LIDX(idx) (assert(ISLIDX(idx)), (idx)/2)
  
  #define EXPORTIDX(idx) \
    ((ISLIDX(idx) ? (IDX2LIDX (idx) + (ps->ohead - ps->oclauses)) : IDX2OIDX(idx)) + 1)
  
  #define IDX2CLS(i) \
    (assert(i), (ISLIDX(i) ? ps->lclauses : ps->oclauses)[(i)/2 - !ISLIDX(i)])
  
  #define IDX2ZHN(i) (assert(i), (ISLIDX(i) ? ps->zhains[(i)/2] : 0))
  
  #define CLS2TRD(c) (((Trd*)(c)) - 1)
  #define CLS2IDX(c) ((((Trd*)(c)) - 1)->idx)
  
  #define CLS2ACT(c) \
    ((Act*)((assert((c)->learned)),assert((c)->size>2),ENDOFCLS(c)))
  
  #define VAR2LIT(v) (ps->lits + 2 * ((v) - ps->vars))
  #define VAR2RNK(v) (ps->rnks + ((v) - ps->vars))
  
  #define RNK2LIT(r) (ps->lits + 2 * ((r) - ps->rnks))
  #define RNK2VAR(r) (ps->vars + ((r) - ps->rnks))
  
  #define BLK_FILL_BYTES 8
  #define SIZE_OF_BLK (sizeof (Blk) - BLK_FILL_BYTES)
  
  #define PTR2BLK(void_ptr) \
    ((void_ptr) ? (Blk*)(((char*)(void_ptr)) - SIZE_OF_BLK) : 0)
  
  #define AVERAGE(a,b) ((b) ? (((double)a) / (double)(b)) : 0.0)
  #define PERCENT(a,b) (100.0 * AVERAGE(a,b))
  
  #ifndef RCODE
  #define ABORT(msg) \
    do { \
      fputs ("*** picosat: " msg "\n", stderr); \
      abort (); \
    } while (0)
  #else
  #define ABORT(msg) \
    do { \
      Rf_error (msg); \
    } while (0)
  #endif
  
  #define ABORTIF(cond,msg) \
    do { \
      if (!(cond)) break; \
      ABORT (msg); \
    } while (0)
  
  #define ZEROFLT		(0x00000000u)
  #define EPSFLT		(0x00000001u)
  #define INFFLT		(0xffffffffu)
  
  #define FLTCARRY	(1u << 25)
  #define FLTMSB		(1u << 24)
  #define FLTMAXMANTISSA	(FLTMSB - 1)
  
  #define FLTMANTISSA(d)	((d) & FLTMAXMANTISSA)
  #define FLTEXPONENT(d)	((int)((d) >> 24) - 128)
  
  #define FLTMINEXPONENT	(-128)
  #define FLTMAXEXPONENT	(127)
  
  #define CMPSWAPFLT(a,b) \
    do { \
      Flt tmp; \
      if (((a) < (b))) \
        { \
  	tmp = (a); \
  	(a) = (b); \
  	(b) = tmp; \
        } \
    } while (0)
  
  #define UNPACKFLT(u,m,e) \
    do { \
      (m) = FLTMANTISSA(u); \
      (e) = FLTEXPONENT(u); \
      (m) |= FLTMSB; \
    } while (0)
  
  #define INSERTION_SORT_LIMIT 10
  
  #define SORTING_SWAP(T,p,q) \
  do { \
    T tmp = *(q); \
    *(q) = *(p); \
    *(p) = tmp; \
  } while (0)
  
  #define SORTING_CMP_SWAP(T,cmp,p,q) \
  do { \
    if ((cmp) (ps, *(p), *(q)) > 0) \
      SORTING_SWAP (T, p, q); \
  } while(0)
  
  #define QUICKSORT_PARTITION(T,cmp,a,l,r) \
  do { \
    T pivot; \
    int j; \
    i = (l) - 1; 			/* result in 'i' */ \
    j = (r); \
    pivot = (a)[j]; \
    for (;;) \
      { \
        while ((cmp) (ps, (a)[++i], pivot) < 0) \
  	; \
        while ((cmp) (ps, pivot, (a)[--j]) < 0) \
          if (j == (l)) \
  	  break; \
        if (i >= j) \
  	break; \
        SORTING_SWAP (T, (a) + i, (a) + j); \
      } \
    SORTING_SWAP (T, (a) + i, (a) + (r)); \
  } while(0)
  
  #define QUICKSORT(T,cmp,a,n) \
  do { \
    int l = 0, r = (n) - 1, m, ll, rr, i; \
    assert (ps->ihead == ps->indices); \
    if (r - l <= INSERTION_SORT_LIMIT) \
      break; \
    for (;;) \
      { \
        m = (l + r) / 2; \
        SORTING_SWAP (T, (a) + m, (a) + r - 1); \
        SORTING_CMP_SWAP (T, cmp, (a) + l, (a) + r - 1); \
        SORTING_CMP_SWAP (T, cmp, (a) + l, (a) + r); \
        SORTING_CMP_SWAP (T, cmp, (a) + r - 1, (a) + r); \
        QUICKSORT_PARTITION (T, cmp, (a), l + 1, r - 1); \
        if (i - l < r - i) \
  	{ \
  	  ll = i + 1; \
  	  rr = r; \
  	  r = i - 1; \
  	} \
        else \
  	{ \
  	  ll = l; \
  	  rr = i - 1; \
  	  l = i + 1; \
  	} \
        if (r - l > INSERTION_SORT_LIMIT) \
  	{ \
  	  assert (rr - ll > INSERTION_SORT_LIMIT); \
  	  if (ps->ihead == ps->eoi) \
  	    ENLARGE (ps->indices, ps->ihead, ps->eoi); \
  	  *ps->ihead++ = ll; \
  	  if (ps->ihead == ps->eoi) \
  	    ENLARGE (ps->indices, ps->ihead, ps->eoi); \
  	  *ps->ihead++ = rr; \
  	} \
        else if (rr - ll > INSERTION_SORT_LIMIT) \
          { \
  	  l = ll; \
  	  r = rr; \
  	} \
        else if (ps->ihead > ps->indices) \
  	{ \
  	  r = *--ps->ihead; \
  	  l = *--ps->ihead; \
  	} \
        else \
  	break; \
      } \
  } while (0)
  
  #define INSERTION_SORT(T,cmp,a,n) \
  do { \
    T pivot; \
    int l = 0, r = (n) - 1, i, j; \
    for (i = r; i > l; i--) \
      SORTING_CMP_SWAP (T, cmp, (a) + i - 1, (a) + i); \
    for (i = l + 2; i <= r; i++)  \
      { \
        j = i; \
        pivot = (a)[i]; \
        while ((cmp) (ps, pivot, (a)[j - 1]) < 0) \
          { \
  	  (a)[j] = (a)[j - 1]; \
  	  j--; \
  	} \
        (a)[j] = pivot; \
      } \
  } while (0)
  
  #ifdef NDEBUG
  #define CHECK_SORTED(cmp,a,n) do { } while(0)
  #else
  #define CHECK_SORTED(cmp,a,n) \
  do { \
    int i; \
    for (i = 0; i < (n) - 1; i++) \
      assert ((cmp) (ps, (a)[i], (a)[i + 1]) <= 0); \
  } while(0)
  #endif
  
  #define SORT(T,cmp,a,n) \
  do { \
    T * aa = (a); \
    int nn = (n); \
    QUICKSORT (T, cmp, aa, nn); \
    INSERTION_SORT (T, cmp, aa, nn); \
    assert (ps->ihead == ps->indices); \
    CHECK_SORTED (cmp, aa, nn); \
  } while (0)
  
  #define WRDSZ (sizeof (long) * 8)
  
  #ifdef RCODE
  #define fprintf(...) do { } while (0)
  #define vfprintf(...) do { } while (0)
  #define fputs(...) do { } while (0)
  #define fputc(...) do { } while (0)
  #endif
  
  typedef unsigned Flt;		/* 32 bit deterministic soft float */
  typedef Flt Act;		/* clause and variable activity */
  typedef struct Blk Blk;		/* allocated memory block */
  typedef struct Cls Cls;		/* clause */
  typedef struct Lit Lit;		/* literal */
  typedef struct Rnk Rnk;		/* variable to score mapping */
  typedef signed char Val;	/* TRUE, UNDEF, FALSE */
  typedef struct Var Var;		/* variable */
  #ifdef TRACE
  typedef struct Trd Trd;		/* trace data for clauses */
  typedef struct Zhn Zhn;		/* compressed chain (=zain) data */
  typedef unsigned char Znt;	/* compressed antecedent data */
  #endif
  
  #ifdef NO_BINARY_CLAUSES
  typedef struct Ltk Ltk;
  
  struct Ltk
  {
    Lit ** start;
    unsigned count : WRDSZ == 32 ? 27 : 32;
    unsigned ldsize : WRDSZ == 32 ? 5 : 32;
  };
  #endif
  
  struct Lit
  {
    Val val;
  };
  
  struct Var
  {
    unsigned mark		: 1;	/*bit 1*/
    unsigned resolved	: 1;	/*bit 2*/
    unsigned phase	: 1;	/*bit 3*/
    unsigned assigned	: 1;	/*bit 4*/
    unsigned used		: 1;	/*bit 5*/
    unsigned failed	: 1;	/*bit 6*/
    unsigned internal	: 1;	/*bit 7*/
    unsigned usedefphase  : 1;    /*bit 8*/
    unsigned defphase     : 1;    /*bit 9*/
    unsigned msspos       : 1;    /*bit 10*/
    unsigned mssneg       : 1;    /*bit 11*/
    unsigned humuspos     : 1;    /*bit 12*/
    unsigned humusneg     : 1;    /*bit 13*/
    unsigned partial      : 1;    /*bit 14*/
  #ifdef TRACE
    unsigned core		: 1;	/*bit 15*/
  #endif
    unsigned level;
    Cls *reason;
  #ifndef NADC
    Lit ** inado;
    Lit ** ado;
    Lit *** adotabpos;
  #endif
  };
  
  struct Rnk
  {
    Act score;
    unsigned pos : 30;			/* 0 iff not on heap */
    unsigned moreimportant : 1;
    unsigned lessimportant : 1;
  };
  
  struct Cls
  {
    unsigned size;
  
    unsigned collect:1;	/* bit 1 */
    unsigned learned:1;	/* bit 2 */
    unsigned locked:1;	/* bit 3 */
    unsigned used:1;	/* bit 4 */
  #ifndef NDEBUG
    unsigned connected:1;	/* bit 5 */
  #endif
  #ifdef TRACE
    unsigned collected:1;	/* bit 6 */
    unsigned core:1;	/* bit 7 */
  #endif
  
  #define LDMAXGLUE 25	/* 32 - 7 */
  #define MAXGLUE 	((1<<LDMAXGLUE)-1)
  
    unsigned glue:LDMAXGLUE;
  
    Cls *next[2];
    Lit *lits[2];
  };
  
  #ifdef TRACE
  struct Zhn
  {
    unsigned ref:31;
    unsigned core:1;
    Znt * liz;
    Znt znt[0];
  };
  
  struct Trd
  {
    unsigned idx;
    Cls cls[0];
  };
  #endif
  
  struct Blk
  {
  #ifndef NDEBUG
    union
    {
      size_t size;		/* this is what we really use */
      void *as_two_ptrs[2];	/* 2 * sizeof (void*) alignment of data */
    }
    header;
  #endif
    char data[BLK_FILL_BYTES];
  };
  
  enum State
  {
    RESET = 0,
    READY = 1,
    SAT = 2,
    UNSAT = 3,
    UNKNOWN = 4,
  };
  
  enum Phase
  {
    POSPHASE,
    NEGPHASE,
    JWLPHASE,
    RNDPHASE,
  };
  
  struct PicoSAT 
  {
    enum State state;
    enum Phase defaultphase;
    int last_sat_call_result;
  
    FILE *out;
    char * prefix;
    int verbosity;
    int plain;
    unsigned LEVEL;
    unsigned max_var;
    unsigned size_vars;
  
    Lit *lits;
    Var *vars;
    Rnk *rnks;
    Flt *jwh;
    Cls **htps;
  #ifndef NDSC
    Cls **dhtps;
  #endif
  #ifdef NO_BINARY_CLAUSES
    Ltk *impls;
    Cls impl, cimpl;
    int implvalid, cimplvalid;
  #else
    Cls **impls;
  #endif
    Lit **trail, **thead, **eot, **ttail, ** ttail2;
  #ifndef NADC
    Lit **ttailado;
  #endif
    unsigned adecidelevel;
    Lit **als, **alshead, **alstail, **eoals;
    Lit **CLS, **clshead, **eocls;
    int *rils, *rilshead, *eorils;
    int *cils, *cilshead, *eocils;
    int *fals, *falshead, *eofals;
    int *mass, szmass;
    int *mssass, szmssass;
    int *mcsass, nmcsass, szmcsass;
    int *humus, szhumus;
    Lit *failed_assumption;
    int extracted_all_failed_assumptions;
    Rnk **heap, **hhead, **eoh;
    Cls **oclauses, **ohead, **eoo;	/* original clauses */
    Cls **lclauses, **lhead, ** EOL;	/* learned clauses */
    int * soclauses, * sohead, * eoso; /* saved original clauses */
    int saveorig;
    int partial;
  #ifdef TRACE
    int trace;
    Zhn **zhains, **zhead, **eoz;
    int ocore;
  #endif
    FILE * rup;
    int rupstarted;
    int rupvariables;
    int rupclauses;
    Cls *mtcls;
    Cls *conflict;
    Lit **added, **ahead, **eoa;
    Var **marked, **mhead, **eom;
    Var **dfs, **dhead, **eod;
    Cls **resolved, **rhead, **eor;
    unsigned char *levels, *levelshead, *eolevels;
    unsigned *dused, *dusedhead, *eodused;
    unsigned char *buffer, *bhead, *eob;
    Act vinc, lscore, ilvinc, ifvinc;
  #ifdef VISCORES
    Act fvinc, nvinc;
  #endif
    Act cinc, lcinc, ilcinc, fcinc;
    unsigned srng;
    size_t current_bytes;
    size_t max_bytes;
    size_t recycled;
    double seconds, flseconds;
    double entered;
    unsigned nentered;
    int measurealltimeinlib;
    char *rline[2];
    int szrline, RCOUNT;
    double levelsum;
    unsigned iterations;
    int reports;
    int lastrheader;
    unsigned calls;
    unsigned decisions;
    unsigned restarts;
    unsigned simps;
    unsigned fsimplify;
    unsigned isimplify;
    unsigned reductions;
    unsigned lreduce;
    unsigned lreduceadjustcnt;
    unsigned lreduceadjustinc;
    unsigned lastreduceconflicts;
    unsigned llocked;	/* locked large learned clauses */
    unsigned lrestart;
  #ifdef NLUBY
    unsigned drestart;
    unsigned ddrestart;
  #else
    unsigned lubycnt;
    unsigned lubymaxdelta;
    int waslubymaxdelta;
  #endif
    unsigned long long lsimplify;
    unsigned long long propagations;
    unsigned long long lpropagations;
    unsigned fixed;		/* top level assignments */
  #ifndef NFL
    unsigned failedlits;
    unsigned ifailedlits;
    unsigned efailedlits;
    unsigned flcalls;
  #ifdef STATS
    unsigned flrounds;
    unsigned long long flprops;
    unsigned long long floopsed, fltried, flskipped;
  #endif
    unsigned long long fllimit;
    int simplifying;
    Lit ** saved;
    unsigned saved_size;
  #endif
    unsigned conflicts;
    unsigned contexts;
    unsigned internals;
    unsigned noclauses;	/* current number large original clauses */
    unsigned nlclauses;	/* current number large learned clauses */
    unsigned olits;		/* current literals in large original clauses */
    unsigned llits;		/* current literals in large learned clauses */
    unsigned oadded;		/* added original clauses */
    unsigned ladded;		/* added learned clauses */
    unsigned loadded;	/* added original large clauses */
    unsigned lladded;	/* added learned large clauses */
    unsigned addedclauses;	/* oadded + ladded */
    unsigned vused;		/* used variables */
    unsigned llitsadded;	/* added learned literals */
    unsigned long long visits;
  #ifdef STATS
    unsigned loused;		/* used large original clauses */
    unsigned llused;		/* used large learned clauses */
    unsigned long long bvisits;
    unsigned long long tvisits;
    unsigned long long lvisits;
    unsigned long long othertrue;
    unsigned long long othertrue2;
    unsigned long long othertruel;
    unsigned long long othertrue2u;
    unsigned long long othertruelu;
    unsigned long long ltraversals;
    unsigned long long traversals;
  #ifdef TRACE
    unsigned long long antecedents;
  #endif
    unsigned uips;
    unsigned znts;
    unsigned assumptions;
    unsigned rdecisions;
    unsigned sdecisions;
    size_t srecycled;
    size_t rrecycled;
    unsigned long long derefs;
  #endif
    unsigned minimizedllits;
    unsigned nonminimizedllits;
  #ifndef NADC
    Lit *** ados, *** hados, *** eados;
    Lit *** adotab;
    unsigned nadotab;
    unsigned szadotab;
    Cls * adoconflict;
    unsigned adoconflicts;
    unsigned adoconflictlimit;
    int addingtoado;
    int adodisabled;
  #endif
    unsigned long long flips;
  #ifdef STATS
    unsigned long long FORCED;
    unsigned long long assignments;
    unsigned inclreduces;
    unsigned staticphasedecisions;
    unsigned skippedrestarts;
  #endif
    int * indices, * ihead, *eoi; 
    unsigned sdflips;
  
    unsigned long long saved_flips;
    unsigned saved_max_var;
    unsigned min_flipped;
  
    void * emgr;
    picosat_malloc enew;
    picosat_realloc eresize;
    picosat_free edelete;
  
    struct {
      void * state;
      int (*function) (void *);
    } interrupt;
  
  #ifdef VISCORES
    FILE * fviscores;
  #endif
  };
  
  typedef PicoSAT PS;
  
  static Flt
  packflt (unsigned m, int e)
  {
    Flt res;
    assert (m < FLTMSB);
    assert (FLTMINEXPONENT <= e);
    assert (e <= FLTMAXEXPONENT);
    res = m | ((unsigned)(e + 128) << 24);
    return res;
  }
  
  static Flt
  base2flt (unsigned m, int e)
  {
    if (!m)
      return ZEROFLT;
  
    if (m < FLTMSB)
      {
        do
  	{
  	  if (e <= FLTMINEXPONENT)
  	    return EPSFLT;
  
  	  e--;
  	  m <<= 1;
  
  	}
        while (m < FLTMSB);
      }
    else
      {
        while (m >= FLTCARRY)
  	{
  	  if (e >= FLTMAXEXPONENT)
  	    return INFFLT;
  
  	  e++;
  	  m >>= 1;
  	}
      }
  
    m &= ~FLTMSB;
    return packflt (m, e);
  }
  
  static Flt
  addflt (Flt a, Flt b)
  {
    unsigned ma, mb, delta;
    int ea, eb;
  
    CMPSWAPFLT (a, b);
    if (!b)
      return a;
  
    UNPACKFLT (a, ma, ea);
    UNPACKFLT (b, mb, eb);
  
    assert (ea >= eb);
    delta = ea - eb;
    if (delta < 32) mb >>= delta; else mb = 0;
    if (!mb)
      return a;
  
    ma += mb;
    if (ma & FLTCARRY)
      {
        if (ea == FLTMAXEXPONENT)
  	return INFFLT;
  
        ea++;
        ma >>= 1;
      }
  
    assert (ma < FLTCARRY);
    ma &= FLTMAXMANTISSA;
  
    return packflt (ma, ea);
  }
  
  static Flt
  mulflt (Flt a, Flt b)
  {
    unsigned ma, mb;
    unsigned long long accu;
    int ea, eb;
  
    CMPSWAPFLT (a, b);
    if (!b)
      return ZEROFLT;
  
    UNPACKFLT (a, ma, ea);
    UNPACKFLT (b, mb, eb);
  
    ea += eb;
    ea += 24;
    if (ea > FLTMAXEXPONENT)
      return INFFLT;
  
    if (ea < FLTMINEXPONENT)
      return EPSFLT;
  
    accu = ma;
    accu *= mb;
    accu >>= 24;
  
    if (accu >= FLTCARRY)
      {
        if (ea == FLTMAXEXPONENT)
  	return INFFLT;
  
        ea++;
        accu >>= 1;
  
        if (accu >= FLTCARRY)
  	return INFFLT;
      }
  
    assert (accu < FLTCARRY);
    assert (accu & FLTMSB);
  
    ma = accu;
    ma &= ~FLTMSB;
  
    return packflt (ma, ea);
  }
  
  static Flt
  ascii2flt (const char *str)
  {
    Flt ten = base2flt (10, 0);
    Flt onetenth = base2flt (26843546, -28);
    Flt res = ZEROFLT, tmp, base;
    const char *p = str;
    int ch;
  
    ch = *p++;
  
    if (ch != '.')
      {
        if (!isdigit (ch))
  	return INFFLT;	/* better abort ? */
  
        res = base2flt (ch - '0', 0);
  
        while ((ch = *p++))
  	{
  	  if (ch == '.')
  	    break;
  
  	  if (!isdigit (ch))
  	    return INFFLT;	/* better abort? */
  
  	  res = mulflt (res, ten);
  	  tmp = base2flt (ch - '0', 0);
  	  res = addflt (res, tmp);
  	}
      }
  
    if (ch == '.')
      {
        ch = *p++;
        if (!isdigit (ch))
  	return INFFLT;	/* better abort ? */
  
        base = onetenth;
        tmp = mulflt (base2flt (ch - '0', 0), base);
        res = addflt (res, tmp);
  
        while ((ch = *p++))
  	{
  	  if (!isdigit (ch))
  	    return INFFLT;	/* better abort? */
  
  	  base = mulflt (base, onetenth);
  	  tmp = mulflt (base2flt (ch - '0', 0), base);
  	  res = addflt (res, tmp);
  	}
      }
  
    return res;
  }
  
  #if defined(VISCORES)
  
  static double
  flt2double (Flt f)
  {
    double res;
    unsigned m;
    int e, i;
  
    UNPACKFLT (f, m, e);
    res = m;
  
    if (e < 0)
      {
        for (i = e; i < 0; i++)
  	res *= 0.5;
      }
    else
      {
        for (i = 0; i < e; i++)
  	res *= 2.0;
      }
  
    return res;
  }
  
  #endif
  
  static int
  log2flt (Flt a)
  {
    return FLTEXPONENT (a) + 24;
  }
  
  static int
  cmpflt (Flt a, Flt b)
  {
    if (a < b)
      return -1;
  
    if (a > b)
      return 1;
  
    return 0;
  }
  
  static void *
  new (PS * ps, size_t size)
  {
    size_t bytes;
    Blk *b;
    
    if (!size)
      return 0;
  
    bytes = size + SIZE_OF_BLK;
  
    if (ps->enew)
      b = ps->enew (ps->emgr, bytes);
    else
      b = malloc (bytes);
  
    ABORTIF (!b, "out of memory in 'new'");
  #ifndef NDEBUG
    b->header.size = size;
  #endif
    ps->current_bytes += size;
    if (ps->current_bytes > ps->max_bytes)
      ps->max_bytes = ps->current_bytes;
    return b->data;
  }
  
  static void
  delete (PS * ps, void *void_ptr, size_t size)
  {
    size_t bytes;
    Blk *b;
  
    if (!void_ptr)
      {
        assert (!size);
        return;
      }
  
    assert (size);
    b = PTR2BLK (void_ptr);
  
    assert (size <= ps->current_bytes);
    ps->current_bytes -= size;
  
    assert (b->header.size == size);
  
    bytes = size + SIZE_OF_BLK;
    if (ps->edelete)
      ps->edelete (ps->emgr, b, bytes);
    else
      free (b);
  }
  
  static void *
  resize (PS * ps, void *void_ptr, size_t old_size, size_t new_size)
  {
    size_t old_bytes, new_bytes;
    Blk *b;
  
    b = PTR2BLK (void_ptr);
  
    assert (old_size <= ps->current_bytes);
    ps->current_bytes -= old_size;
  
    if ((old_bytes = old_size))
      {
        assert (old_size && b && b->header.size == old_size);
        old_bytes += SIZE_OF_BLK;
      }
    else
      assert (!b);
  
    if ((new_bytes = new_size))
      new_bytes += SIZE_OF_BLK;
  
    if (ps->eresize)
      b = ps->eresize (ps->emgr, b, old_bytes, new_bytes);
    else
      b = realloc (b, new_bytes);
  
    if (!new_size)
      {
        assert (!b);
        return 0;
      }
  
    ABORTIF (!b, "out of memory in 'resize'");
  #ifndef NDEBUG
    b->header.size = new_size;
  #endif
  
    ps->current_bytes += new_size;
    if (ps->current_bytes > ps->max_bytes)
      ps->max_bytes = ps->current_bytes;
  
    return b->data;
  }
  
  static unsigned
  int2unsigned (int l)
  {
    return (l < 0) ? 1 + 2 * -l : 2 * l;
  }
  
  static Lit *
  int2lit (PS * ps, int l)
  {
    return ps->lits + int2unsigned (l);
  }
  
  static Lit **
  end_of_lits (Cls * c)
  {
    return (Lit**)c->lits + c->size;
  }
  
  #if !defined(NDEBUG) || defined(LOGGING)
  
  static void
  dumplits (PS * ps, Lit ** l, Lit ** end)
  {
    int first;
    Lit ** p;
  
    if (l == end)
      {
        /* empty clause */
      }
    else if (l + 1 == end)
      {
        fprintf (ps->out, "%d ", LIT2INT (l[0]));
      }
    else
      { 
        assert (l + 2 <= end);
        first = (abs (LIT2INT (l[0])) > abs (LIT2INT (l[1])));
        fprintf (ps->out, "%d ", LIT2INT (l[first]));
        fprintf (ps->out, "%d ", LIT2INT (l[!first]));
        for (p = l + 2; p < end; p++)
  	 fprintf (ps->out, "%d ", LIT2INT (*p));
      }
  
    fputc ('0', ps->out);
  }
  
  static void
  dumpcls (PS * ps, Cls * c)
  {
    Lit **end;
  
    if (c)
      {
        end = end_of_lits (c);
        dumplits (ps, c->lits, end);
  #ifdef TRACE
        if (ps->trace)
  	 fprintf (ps->out, " clause(%u)", CLS2IDX (c));
  #endif
      }
    else
      fputs ("DECISION", ps->out);
  }
  
  static void
  dumpclsnl (PS * ps, Cls * c)
  {
    dumpcls (ps, c);
    fputc ('\n', ps->out);
  }
  
  void
  dumpcnf (PS * ps)
  {
    Cls **p, *c;
  
    for (p = SOC; p != EOC; p = NXC (p))
      {
        c = *p;
  
        if (!c)
  	continue;
  
  #ifdef TRACE
        if (c->collected)
  	continue;
  #endif
  
        dumpclsnl (ps, *p);
      }
  }
  
  #endif
  
  static void
  delete_prefix (PS * ps)
  {
    if (!ps->prefix)
      return;
      
    delete (ps, ps->prefix, strlen (ps->prefix) + 1);
    ps->prefix = 0;
  }
  
  static void
  new_prefix (PS * ps, const char * str)
  {
    delete_prefix (ps);
    assert (str);
    ps->prefix = new (ps, strlen (str) + 1);
    strcpy (ps->prefix, str);
  }
  
  static PS *
  init (void * pmgr, 
        picosat_malloc pnew, picosat_realloc presize, picosat_free pdelete)
  {
    PS * ps;
  
  #if 0
    int count = 3 - !pnew - !presize - !pdelete;
  
    ABORTIF (count && !pnew, "API usage: missing 'picosat_set_new'");
    ABORTIF (count && !presize, "API usage: missing 'picosat_set_resize'");
    ABORTIF (count && !pdelete, "API usage: missing 'picosat_set_delete'");
  #endif
  
    ps = pnew ? pnew (pmgr, sizeof *ps) : malloc (sizeof *ps);
    ABORTIF (!ps, "failed to allocate memory for PicoSAT manager");
    memset (ps, 0, sizeof *ps);
  
    ps->emgr = pmgr;
    ps->enew = pnew;
    ps->eresize = presize;
    ps->edelete = pdelete;
  
    ps->size_vars = 1;
    ps->state = RESET;
    ps->defaultphase = JWLPHASE;
  #ifdef TRACE
    ps->ocore = -1;
  #endif
    ps->lastrheader = -2;
  #ifndef NADC
    ps->adoconflictlimit = UINT_MAX;
  #endif
    ps->min_flipped = UINT_MAX;
  
    NEWN (ps->lits, 2 * ps->size_vars);
    NEWN (ps->jwh, 2 * ps->size_vars);
    NEWN (ps->htps, 2 * ps->size_vars);
  #ifndef NDSC
    NEWN (ps->dhtps, 2 * ps->size_vars);
  #endif
    NEWN (ps->impls, 2 * ps->size_vars);
    NEWN (ps->vars, ps->size_vars);
    NEWN (ps->rnks, ps->size_vars);
  
    /* because '0' pos denotes not on heap
     */
    ENLARGE (ps->heap, ps->hhead, ps->eoh); 
    ps->hhead = ps->heap + 1;
  
    ps->vinc = base2flt (1, 0);		/* initial var activity */
    ps->ifvinc = ascii2flt ("1.05");	/* var score rescore factor */
  #ifdef VISCORES
    ps->fvinc = ascii2flt ("0.9523809");	/*     1/f =     1/1.05 */
    ps->nvinc = ascii2flt ("0.0476191");	/* 1 - 1/f = 1 - 1/1.05 */
  #endif
    ps->lscore = base2flt (1, 90);	/* var activity rescore limit */
    ps->ilvinc = base2flt (1, -90);	/* inverse of 'lscore' */
  
    ps->cinc = base2flt (1, 0);		/* initial clause activity */
    ps->fcinc = ascii2flt ("1.001");	/* cls activity rescore factor */
    ps->lcinc = base2flt (1, 90);		/* cls activity rescore limit */
    ps->ilcinc = base2flt (1, -90);	/* inverse of 'ilcinc' */
  
    ps->lreduceadjustcnt = ps->lreduceadjustinc = 100;
    ps->lpropagations = ~0ull;
  
  #ifndef RCODE
    ps->out = stdout;
  #else
    ps->out = 0;
  #endif
    new_prefix (ps, "c ");
    ps->verbosity = 0;
    ps->plain = 0;
  
  #ifdef NO_BINARY_CLAUSES
    memset (&ps->impl, 0, sizeof (ps->impl));
    ps->impl.size = 2;
  
    memset (&ps->cimpl, 0, sizeof (ps->impl));
    ps->cimpl.size = 2;
  #endif
  
  #ifdef VISCORES
    ps->fviscores = popen (
      "/usr/bin/gnuplot -background black"
      " -xrm 'gnuplot*textColor:white'"
      " -xrm 'gnuplot*borderColor:white'"
      " -xrm 'gnuplot*axisColor:white'"
      , "w");
    fprintf (ps->fviscores, "unset key\n");
    // fprintf (ps->fviscores, "set log y\n");
    fflush (ps->fviscores);
    system ("rm -rf /tmp/picosat-viscores");
    system ("mkdir /tmp/picosat-viscores");
    system ("mkdir /tmp/picosat-viscores/data");
  #ifdef WRITEGIF
    system ("mkdir /tmp/picosat-viscores/gif");
    fprintf (ps->fviscores,
             "set terminal gif giant animate opt size 1024,768 x000000 xffffff"
  	   "\n");
  
    fprintf (ps->fviscores, 
             "set output \"/tmp/picosat-viscores/gif/animated.gif\"\n");
  #endif
  #endif
    ps->defaultphase = JWLPHASE;
    ps->state = READY;
    ps->last_sat_call_result = 0;
  
    return ps;
  }
  
  static size_t
  bytes_clause (PS * ps, unsigned size, unsigned learned)
  {
    size_t res;
  
    res = sizeof (Cls);
    res += size * sizeof (Lit *);
    res -= 2 * sizeof (Lit *);
  
    if (learned && size > 2)
      res += sizeof (Act);	/* add activity */
  
  #ifdef TRACE
    if (ps->trace)
      res += sizeof (Trd);	/* add trace data */
  #else
    (void) ps;
  #endif
  
    return res;
  }
  
  static Cls *
  new_clause (PS * ps, unsigned size, unsigned learned)
  {
    size_t bytes;
    void * tmp;
  #ifdef TRACE
    Trd *trd;
  #endif
    Cls *res;
  
    bytes = bytes_clause (ps, size, learned);
    tmp = new (ps, bytes);
  
  #ifdef TRACE
    if (ps->trace)
      {
        trd = tmp;
  
        if (learned)
  	trd->idx = LIDX2IDX (ps->lhead - ps->lclauses);
        else
  	trd->idx = OIDX2IDX (ps->ohead - ps->oclauses);
  
        res = trd->cls;
      }
    else
  #endif
      res = tmp;
  
    res->size = size;
    res->learned = learned;
  
    res->collect = 0;
  #ifndef NDEBUG
    res->connected = 0;
  #endif
    res->locked = 0;
    res->used = 0;
  #ifdef TRACE
    res->core = 0;
    res->collected = 0;
  #endif
  
    if (learned && size > 2)
      {
        Act * p = CLS2ACT (res);
        *p = ps->cinc;
      }
  
    return res;
  }
  
  static void
  delete_clause (PS * ps, Cls * c)
  {
    size_t bytes;
  #ifdef TRACE
    Trd *trd;
  #endif
  
    bytes = bytes_clause (ps, c->size, c->learned);
  
  #ifdef TRACE
    if (ps->trace)
      {
        trd = CLS2TRD (c);
        delete (ps, trd, bytes);
      }
    else
  #endif
      delete (ps, c, bytes);
  }
  
  static void
  delete_clauses (PS * ps)
  {
    Cls **p;
    for (p = SOC; p != EOC; p = NXC (p))
      if (*p)
        delete_clause (ps, *p);
  
    DELETEN (ps->oclauses, ps->eoo - ps->oclauses);
    DELETEN (ps->lclauses, ps->EOL - ps->lclauses);
  
    ps->ohead = ps->eoo = ps->lhead = ps->EOL = 0;
  }
  
  #ifdef TRACE
  
  static void
  delete_zhain (PS * ps, Zhn * zhain)
  {
    const Znt *p, *znt;
  
    assert (zhain);
  
    znt = zhain->znt;
    for (p = znt; *p; p++)
      ;
  
    delete (ps, zhain, sizeof (Zhn) + (p - znt) + 1);
  }
  
  static void
  delete_zhains (PS * ps)
  {
    Zhn **p, *z;
    for (p = ps->zhains; p < ps->zhead; p++)
      if ((z = *p))
        delete_zhain (ps, z);
  
    DELETEN (ps->zhains, ps->eoz - ps->zhains);
    ps->eoz = ps->zhead = 0;
  }
  
  #endif
  
  #ifdef NO_BINARY_CLAUSES
  static void
  lrelease (PS * ps, Ltk * stk)
  {
    if (stk->start)
      DELETEN (stk->start, (1 << (stk->ldsize)));
    memset (stk, 0, sizeof (*stk));
  }
  #endif
  
  #ifndef NADC
  
  static unsigned
  llength (Lit ** a)
  {
    Lit ** p;
    for (p = a; *p; p++)
      ;
    return p - a;
  }
  
  static void
  resetadoconflict (PS * ps)
  {
    assert (ps->adoconflict);
    delete_clause (ps, ps->adoconflict);
    ps->adoconflict = 0;
  }
  
  static void
  reset_ados (PS * ps)
  {
    Lit *** p;
  
    for (p = ps->ados; p < ps->hados; p++)
      DELETEN (*p, llength (*p) + 1);
  
    DELETEN (ps->ados, ps->eados - ps->ados);
    ps->hados = ps->eados = 0;
  
    DELETEN (ps->adotab, ps->szadotab);
    ps->szadotab = ps->nadotab = 0;
  
    if (ps->adoconflict)
      resetadoconflict (ps);
  
    ps->adoconflicts = 0;
    ps->adoconflictlimit = UINT_MAX;
    ps->adodisabled = 0;
  }
  
  #endif
  
  static void
  reset (PS * ps)
  {
    ABORTIF (!ps || 
             ps->state == RESET, "API usage: reset without initialization");
  
    delete_clauses (ps);
  #ifdef TRACE
    delete_zhains (ps);
  #endif
  #ifdef NO_BINARY_CLAUSES
    {
      unsigned i;
      for (i = 2; i <= 2 * ps->max_var + 1; i++)
        lrelease (ps, ps->impls + i);
    }
  #endif
  #ifndef NADC
    reset_ados (ps);
  #endif
  #ifndef NFL
    DELETEN (ps->saved, ps->saved_size);
  #endif
    DELETEN (ps->htps, 2 * ps->size_vars);
  #ifndef NDSC
    DELETEN (ps->dhtps, 2 * ps->size_vars);
  #endif
    DELETEN (ps->impls, 2 * ps->size_vars);
    DELETEN (ps->lits, 2 * ps->size_vars);
    DELETEN (ps->jwh, 2 * ps->size_vars);
    DELETEN (ps->vars, ps->size_vars);
    DELETEN (ps->rnks, ps->size_vars);
    DELETEN (ps->trail, ps->eot - ps->trail);
    DELETEN (ps->heap, ps->eoh - ps->heap);
    DELETEN (ps->als, ps->eoals - ps->als);
    DELETEN (ps->CLS, ps->eocls - ps->CLS);
    DELETEN (ps->rils, ps->eorils - ps->rils);
    DELETEN (ps->cils, ps->eocils - ps->cils);
    DELETEN (ps->fals, ps->eofals - ps->fals);
    DELETEN (ps->mass, ps->szmass);
    DELETEN (ps->mssass, ps->szmssass);
    DELETEN (ps->mcsass, ps->szmcsass);
    DELETEN (ps->humus, ps->szhumus);
    DELETEN (ps->added, ps->eoa - ps->added);
    DELETEN (ps->marked, ps->eom - ps->marked);
    DELETEN (ps->dfs, ps->eod - ps->dfs);
    DELETEN (ps->resolved, ps->eor - ps->resolved);
    DELETEN (ps->levels, ps->eolevels - ps->levels);
    DELETEN (ps->dused, ps->eodused - ps->dused);
    DELETEN (ps->buffer, ps->eob - ps->buffer);
    DELETEN (ps->indices, ps->eoi - ps->indices);
    DELETEN (ps->soclauses, ps->eoso - ps->soclauses);
    delete_prefix (ps);
    delete (ps, ps->rline[0], ps->szrline);
    delete (ps, ps->rline[1], ps->szrline);
    assert (getenv ("LEAK") || !ps->current_bytes);	/* found leak if failing */
  #ifdef VISCORES
    pclose (ps->fviscores);
  #endif
    if (ps->edelete)
      ps->edelete (ps->emgr, ps, sizeof *ps);
    else
      free (ps);
  }
  
  inline static void
  tpush (PS * ps, Lit * lit)
  {
    assert (ps->lits < lit && lit <= ps->lits + 2* ps->max_var + 1);
    if (ps->thead == ps->eot)
      {
        unsigned ttail2count = ps->ttail2 - ps->trail;
        unsigned ttailcount = ps->ttail - ps->trail;
  #ifndef NADC
        unsigned ttailadocount = ps->ttailado - ps->trail;
  #endif
        ENLARGE (ps->trail, ps->thead, ps->eot);
        ps->ttail = ps->trail + ttailcount;
        ps->ttail2 = ps->trail + ttail2count;
  #ifndef NADC
        ps->ttailado = ps->trail + ttailadocount;
  #endif
      }
  
    *ps->thead++ = lit;
  }
  
  static void
  assign_reason (PS * ps, Var * v, Cls * reason)
  {
  #if defined(NO_BINARY_CLAUSES) && !defined(NDEBUG)
    assert (reason != &ps->impl);
  #else
    (void) ps;
  #endif
    v->reason = reason;
  }
  
  static void
  assign_phase (PS * ps, Lit * lit)
  {
    unsigned new_phase, idx;
    Var * v = LIT2VAR (lit);
  
  #ifndef NFL
    /* In 'simplifying' mode we only need to keep 'min_flipped' up to date if
     * we force assignments on the top level.   The other assignments will be
     * undone and thus we can keep the old saved value of the phase.
     */
    if (!ps->LEVEL || !ps->simplifying)
  #endif
      {
        new_phase = (LIT2SGN (lit) > 0);
  
        if (v->assigned)
  	{
  	  ps->sdflips -= ps->sdflips/FFLIPPED;
  
  	  if (new_phase != v->phase)
  	    {
  	      assert (FFLIPPEDPREC >= FFLIPPED);
  	      ps->sdflips += FFLIPPEDPREC / FFLIPPED;
  	      ps->flips++;
  
  	      idx = LIT2IDX (lit);
  	      if (idx < ps->min_flipped)
  		ps->min_flipped = idx;
  
                NOLOG (fprintf (ps->out, 
  	                      "%sflipped %d\n",
  			       ps->prefix, LIT2INT (lit)));
  	    }
  	}
  
        v->phase = new_phase;
        v->assigned = 1;
      }
  
    lit->val = TRUE;
    NOTLIT (lit)->val = FALSE;
  }
  
  inline static void
  assign (PS * ps, Lit * lit, Cls * reason)
  {
    Var * v = LIT2VAR (lit);
    assert (lit->val == UNDEF);
  #ifdef STATS
    ps->assignments++;
  #endif
    v->level = ps->LEVEL;
    assign_phase (ps, lit);
    assign_reason (ps, v, reason);
    tpush (ps, lit);
  }
  
  inline static int
  cmp_added (PS * ps, Lit * k, Lit * l)
  {
    Val a = k->val, b = l->val;
    Var *u, *v;
    int res;
  
    if (a == UNDEF && b != UNDEF)
      return -1;
  
    if (a != UNDEF && b == UNDEF)
      return 1;
  
    u = LIT2VAR (k);
    v = LIT2VAR (l);
  
    if (a != UNDEF)
      {
        assert (b != UNDEF);
        res = v->level - u->level;
        if (res)
  	return res;		/* larger level first */
      }
  
    res = cmpflt (VAR2RNK (u)->score, VAR2RNK (v)->score);
    if (res)
      return res;			/* smaller activity first */
  
    return u - v;			/* smaller index first */
  }
  
  static void
  sorttwolits (Lit ** v)
  {
    Lit * a = v[0], * b = v[1];
  
    assert (a != b);
  
    if (a < b)
      return;
  
    v[0] = b;
    v[1] = a;
  }
  
  inline static void
  sortlits (PS * ps, Lit ** v, unsigned size)
  {
    if (size == 2)
      sorttwolits (v);	/* same order with and with out 'NO_BINARY_CLAUSES' */
    else
      SORT (Lit *, cmp_added, v, size);
  }
  
  #ifdef NO_BINARY_CLAUSES
  static Cls *
  setimpl (PS * ps, Lit * a, Lit * b)
  {
    assert (!ps->implvalid);
    assert (ps->impl.size == 2);
  
    ps->impl.lits[0] = a;
    ps->impl.lits[1] = b;
  
    sorttwolits (ps->impl.lits);
    ps->implvalid = 1;
  
    return &ps->impl;
  }
  
  static void
  resetimpl (PS * ps)
  {
    ps->implvalid = 0;
  }
  
  static Cls *
  setcimpl (PS * ps, Lit * a, Lit * b)
  {
    assert (!ps->cimplvalid);
    assert (ps->cimpl.size == 2);
  
    ps->cimpl.lits[0] = a;
    ps->cimpl.lits[1] = b;
  
    sorttwolits (ps->cimpl.lits);
    ps->cimplvalid = 1;
  
    return &ps->cimpl;
  }
  
  static void
  resetcimpl (PS * ps)
  {
    assert (ps->cimplvalid);
    ps->cimplvalid = 0;
  }
  
  #endif
  
  static int
  cmp_ptr (PS * ps, void *l, void *k)
  {
    (void) ps;
    return ((char*)l) - (char*)k;		/* arbitrarily already reverse */
  }
  
  static int
  cmp_rnk (Rnk * r, Rnk * s)
  {
    if (!r->moreimportant && s->moreimportant)
      return -1;
  
    if (r->moreimportant && !s->moreimportant)
      return 1;
  
    if (!r->lessimportant && s->lessimportant)
      return 1;
  
    if (r->lessimportant && !s->lessimportant)
      return -1;
  
    if (r->score < s->score)
      return -1;
  
    if (r->score > s->score)
      return 1;
  
    return -cmp_ptr (0, r, s);
  }
  
  static void
  hup (PS * ps, Rnk * v)
  {
    int upos, vpos;
    Rnk *u;
  
  #ifndef NFL
    assert (!ps->simplifying);
  #endif
  
    vpos = v->pos;
  
    assert (0 < vpos);
    assert (vpos < ps->hhead - ps->heap);
    assert (ps->heap[vpos] == v);
  
    while (vpos > 1)
      {
        upos = vpos / 2;
  
        u = ps->heap[upos];
  
        if (cmp_rnk (u, v) > 0)
  	break;
  
        ps->heap[vpos] = u;
        u->pos = vpos;
  
        vpos = upos;
      }
  
    ps->heap[vpos] = v;
    v->pos = vpos;
  }
  
  static Cls *add_simplified_clause (PS *, int);
  
  inline static void
  add_antecedent (PS * ps, Cls * c)
  {
    assert (c);
  
  #ifdef NO_BINARY_CLAUSES
    if (ISLITREASON (c))
      return;
  
    if (c == &ps->impl)
      return;
  #elif defined(STATS) && defined(TRACE)
    ps->antecedents++;
  #endif
    if (ps->rhead == ps->eor)
      ENLARGE (ps->resolved, ps->rhead, ps->eor);
  
    assert (ps->rhead < ps->eor);
    *ps->rhead++ = c;
  }
  
  #ifdef TRACE
  
  #ifdef NO_BINARY_CLAUSES
  #error "can not combine TRACE and NO_BINARY_CLAUSES"
  #endif
  
  #endif /* TRACE */
  
  static void
  add_lit (PS * ps, Lit * lit)
  {
    assert (lit);
  
    if (ps->ahead == ps->eoa)
      ENLARGE (ps->added, ps->ahead, ps->eoa);
  
    *ps->ahead++ = lit;
  }
  
  static void
  push_var_as_marked (PS * ps, Var * v)
  {
    if (ps->mhead == ps->eom)
      ENLARGE (ps->marked, ps->mhead, ps->eom);
  
    *ps->mhead++ = v;
  }
  
  static void
  mark_var (PS * ps, Var * v)
  {
    assert (!v->mark);
    v->mark = 1;
    push_var_as_marked (ps, v);
  }
  
  #ifdef NO_BINARY_CLAUSES
  
  static Cls *
  impl2reason (PS * ps, Lit * lit)
  {
    Lit * other;
    Cls * res;
    other = ps->impl.lits[0];
    if (lit == other)
      other = ps->impl.lits[1];
    assert (other->val == FALSE);
    res = LIT2REASON (NOTLIT (other));
    resetimpl (ps);
    return res;
  }
  
  #endif
  
  /* Whenever we have a top level derived unit we really should derive a unit
   * clause otherwise the resolutions in 'add_simplified_clause' become
   * incorrect.
   */
  static Cls *
  resolve_top_level_unit (PS * ps, Lit * lit, Cls * reason)
  {
    unsigned count_resolved;
    Lit **p, **eol, *other;
    Var *u, *v;
  
    assert (ps->rhead == ps->resolved);
    assert (ps->ahead == ps->added);
  
    add_lit (ps, lit);
    add_antecedent (ps, reason);
    count_resolved = 1;
    v = LIT2VAR (lit);
  
    eol = end_of_lits (reason);
    for (p = reason->lits; p < eol; p++)
      {
        other = *p;
        u = LIT2VAR (other);
        if (u == v)
  	continue;
  
        add_antecedent (ps, u->reason);
        count_resolved++;
      }
  
    /* Some of the literals could be assumptions.  If at least one
     * variable is not an assumption, we should resolve.
     */
    if (count_resolved >= 2)
      {
  #ifdef NO_BINARY_CLAUSES
        if (reason == &ps->impl)
  	resetimpl (ps);
  #endif
        reason = add_simplified_clause (ps, 1);
  #ifdef NO_BINARY_CLAUSES
        if (reason->size == 2)
  	{
  	  assert (reason == &ps->impl);
  	  reason = impl2reason (ps, lit);
  	}
  #endif
        assign_reason (ps, v, reason);
      }
    else
      {
        ps->ahead = ps->added;
        ps->rhead = ps->resolved;
      }
  
    return reason;
  }
  
  static void
  fixvar (PS * ps, Var * v)
  {
    Rnk * r;
  
    assert (VAR2LIT (v) != UNDEF);
    assert (!v->level);
  
    ps->fixed++;
  
    r = VAR2RNK (v);
    r->score = INFFLT;
  
  #ifndef NFL
    if (ps->simplifying)
      return;
  #endif
  
    if (!r->pos)
      return;
  
    hup (ps, r);
  }
  
  static void
  use_var (PS * ps, Var * v)
  {
    if (v->used)
      return;
  
    v->used = 1;
    ps->vused++;
  }
  
  static void
  assign_forced (PS * ps, Lit * lit, Cls * reason)
  {
    Var *v;
  
    assert (reason);
    assert (lit->val == UNDEF);
  
  #ifdef STATS
    ps->FORCED++;
  #endif
    assign (ps, lit, reason);
  
  #ifdef NO_BINARY_CLAUSES
    assert (reason != &ps->impl);
    if (ISLITREASON (reason)) 
      {
        reason = setimpl (ps, lit, NOTLIT (REASON2LIT (reason)));
        assert (reason);
      }
  #endif
    LOG ( fprintf (ps->out,
                  "%sassign %d at level %d by ",
                  ps->prefix, LIT2INT (lit), ps->LEVEL);
         dumpclsnl (ps, reason));
  
    v = LIT2VAR (lit);
    if (!ps->LEVEL)
      use_var (ps, v);
  
    if (!ps->LEVEL && reason->size > 1)
      {
        reason = resolve_top_level_unit (ps, lit, reason);
        assert (reason);
      }
  
  #ifdef NO_BINARY_CLAUSES
    if (ISLITREASON (reason) || reason == &ps->impl)
      {
        /* DO NOTHING */
      }
    else
  #endif
      {
        assert (!reason->locked);
        reason->locked = 1;
        if (reason->learned && reason->size > 2)
  	ps->llocked++;
      }
  
  #ifdef NO_BINARY_CLAUSES
    if (reason == &ps->impl)
      resetimpl (ps);
  #endif
  
    if (!ps->LEVEL)
      fixvar (ps, v);
  }
  
  #ifdef NO_BINARY_CLAUSES
  
  static void
  lpush (PS * ps, Lit * lit, Cls * c)
  {
    int pos = (c->lits[0] == lit);
    Ltk * s = LIT2IMPLS (lit);
    unsigned oldsize, newsize;
  
    assert (c->size == 2);
  
    if (!s->start)
      {
        assert (!s->count);
        assert (!s->ldsize);
        NEWN (s->start, 1);
      }
    else 
      {
        oldsize = (1 << (s->ldsize));
        assert (s->count <= oldsize);
        if (s->count == oldsize)
  	{
  	  newsize = 2 * oldsize;
  	  RESIZEN (s->start, oldsize, newsize);
  	  s->ldsize++;
  	}
      }
  
    s->start[s->count++] = c->lits[pos];
  }
  
  #endif
  
  static void
  connect_head_tail (PS * ps, Lit * lit, Cls * c)
  {
    Cls ** s;
    assert (c->size >= 1);
    if (c->size == 2)
      {
  #ifdef NO_BINARY_CLAUSES
        lpush (ps, lit, c);
        return;
  #else
        s = LIT2IMPLS (lit);
  #endif
      }
    else
      s = LIT2HTPS (lit);
  
    if (c->lits[0] != lit)
      {
        assert (c->size >= 2);
        assert (c->lits[1] == lit);
        c->next[1] = *s;
      }
    else
      c->next[0] = *s;
  
    *s = c;
  }
  
  #ifdef TRACE
  static void
  zpush (PS * ps, Zhn * zhain)
  {
    assert (ps->trace);
  
    if (ps->zhead == ps->eoz)
      ENLARGE (ps->zhains, ps->zhead, ps->eoz);
  
    *ps->zhead++ = zhain;
  }
  
  static int
  cmp_resolved (PS * ps, Cls * c, Cls * d)
  {
  #ifndef NDEBUG
    assert (ps->trace);
  #else
    (void) ps;
  #endif
    return CLS2IDX (c) - CLS2IDX (d);
  }
  
  static void
  bpushc (PS * ps, unsigned char ch)
  {
    if (ps->bhead == ps->eob)
      ENLARGE (ps->buffer, ps->bhead, ps->eob);
  
    *ps->bhead++ = ch;
  }
  
  static void
  bpushu (PS * ps, unsigned u)
  {
    while (u & ~0x7f)
      {
        bpushc (ps, u | 0x80);
        u >>= 7;
      }
  
    bpushc (ps, u);
  }
  
  static void
  bpushd (PS * ps, unsigned prev, unsigned this)
  {
    unsigned delta;
    assert (prev < this);
    delta = this - prev;
    bpushu (ps, delta);
  }
  
  static void
  add_zhain (PS * ps)
  {
    unsigned prev, this, count, rcount;
    Cls **p, *c;
    Zhn *res;
  
    assert (ps->trace);
    assert (ps->bhead == ps->buffer);
    assert (ps->rhead > ps->resolved);
  
    rcount = ps->rhead - ps->resolved;
    SORT (Cls *, cmp_resolved, ps->resolved, rcount);
  
    prev = 0;
    for (p = ps->resolved; p < ps->rhead; p++)
      {
        c = *p;
        this = CLS2TRD (c)->idx;
        bpushd (ps, prev, this);
        prev = this;
      }
    bpushc (ps, 0);
  
    count = ps->bhead - ps->buffer;
  
    res = new (ps, sizeof (Zhn) + count);
    res->core = 0;
    res->ref = 0;
    memcpy (res->znt, ps->buffer, count);
  
    ps->bhead = ps->buffer;
  #ifdef STATS
    ps->znts += count - 1;
  #endif
    zpush (ps, res);
  }
  
  #endif
  
  static void
  add_resolved (PS * ps, int learned)
  {
  #if defined(STATS) || defined(TRACE)
    Cls **p, *c;
  
    for (p = ps->resolved; p < ps->rhead; p++)
      {
        c = *p;
        if (c->used)
  	continue;
  
        c->used = 1;
  
        if (c->size <= 2)
  	continue;
  
  #ifdef STATS
        if (c->learned)
  	ps->llused++;
        else
  	ps->loused++;
  #endif
      }
  #endif
  
  #ifdef TRACE
    if (learned && ps->trace)
      add_zhain (ps);
  #else
    (void) learned;
  #endif
    ps->rhead = ps->resolved;
  }
  
  static void
  incjwh (PS * ps, Cls * c)
  {
    Lit **p, *lit, ** eol;
    Flt * f, inc, sum;
    unsigned size = 0;
    Var * v;
    Val val;
  
    eol = end_of_lits (c);
  
    for (p = c->lits; p < eol; p++)
      {
        lit = *p;
        val = lit->val;
  
        if (val && ps->LEVEL > 0)
  	{
  	  v = LIT2VAR (lit);
  	  if (v->level > 0)
  	    val = UNDEF;
  	}
  
        if (val == TRUE)
  	return;
  
        if (val != FALSE)
  	size++;
      }
  
    inc = base2flt (1, -size);
  
    for (p = c->lits; p < eol; p++)
      {
        lit = *p;
        f = LIT2JWH (lit);
        sum = addflt (*f, inc);
        *f = sum;
      }
  }
  
  static void
  write_rup_header (PS * ps, FILE * file)
  {
    char line[80];
    int i;
  
    sprintf (line, "%%RUPD32 %u %u", ps->rupvariables, ps->rupclauses);
  
    fputs (line, file);
    for (i = 255 - strlen (line); i >= 0; i--)
      fputc (' ', file);
  
    fputc ('\n', file);
    fflush (file);
  }
  
  static Cls *
  add_simplified_clause (PS * ps, int learned)
  {
    unsigned num_true, num_undef, num_false, size, count_resolved;
    Lit **p, **q, *lit, ** end;
    unsigned litlevel, glue;
    Cls *res, * reason;
    int reentered;
    Val val;
    Var *v;
  #if !defined(NDEBUG) && defined(TRACE)
    unsigned idx;
  #endif
  
    reentered = 0;
  
  REENTER:
  
    size = ps->ahead - ps->added;
  
    add_resolved (ps, learned);
  
    if (learned)
      {
        ps->ladded++;
        ps->llitsadded += size;
        if (size > 2)
  	{
  	  ps->lladded++;
  	  ps->nlclauses++;
  	  ps->llits += size;
  	}
      }
    else
      {
        ps->oadded++;
        if (size > 2)
  	{
  	  ps->loadded++;
  	  ps->noclauses++;
  	  ps->olits += size;
  	}
      }
  
    ps->addedclauses++;
    assert (ps->addedclauses == ps->ladded + ps->oadded);
  
  #ifdef NO_BINARY_CLAUSES
    if (size == 2)
      res = setimpl (ps, ps->added[0], ps->added[1]);
    else
  #endif
      {
        sortlits (ps, ps->added, size); 
  
        if (learned)
  	{
  	  if (ps->lhead == ps->EOL)
  	    {
  	      ENLARGE (ps->lclauses, ps->lhead, ps->EOL);
  
  	      /* A very difficult to find bug, which only occurs if the
  	       * learned clauses stack is immediately allocated before the
  	       * original clauses stack without padding.  In this case, we
  	       * have 'SOC == EOC', which terminates all loops using the
  	       * idiom 'for (p = SOC; p != EOC; p = NXC(p))' immediately.
  	       * Unfortunately this occurred in 'fix_clause_lits' after
  	       * using a recent version of the memory allocator of 'Google'
  	       * perftools in the context of one large benchmark for 
  	       * our SMT solver 'Boolector'.
  	       */
  	      if (ps->EOL == ps->oclauses)
  		ENLARGE (ps->lclauses, ps->lhead, ps->EOL);
  	    }
  
  #if !defined(NDEBUG) && defined(TRACE)
  	  idx = LIDX2IDX (ps->lhead - ps->lclauses);
  #endif
  	}
        else
  	{
  	  if (ps->ohead == ps->eoo)
  	    {
  	      ENLARGE (ps->oclauses, ps->ohead, ps->eoo);
  	      if (ps->EOL == ps->oclauses)
  		ENLARGE (ps->oclauses, ps->ohead, ps->eoo);	/* ditto */
  	    }
  
  #if !defined(NDEBUG) && defined(TRACE)
  	  idx = OIDX2IDX (ps->ohead - ps->oclauses);
  #endif
  	}
  
        assert (ps->EOL != ps->oclauses);			/* ditto */
  
        res = new_clause (ps, size, learned);
  
        glue = 0;
  
        if (learned)
  	{
  	  assert (ps->dusedhead == ps->dused);
  
  	  for (p = ps->added; p < ps->ahead; p++) 
  	    {
  	      lit = *p;
  	      if (lit->val)
  		{
  		  litlevel = LIT2VAR (lit)->level;
  		  assert (litlevel <= ps->LEVEL);
  		  while (ps->levels + litlevel >= ps->levelshead)
  		    {
  		      if (ps->levelshead >= ps->eolevels)
  			ENLARGE (ps->levels, ps->levelshead, ps->eolevels);
  		      assert (ps->levelshead < ps->eolevels);
  		      *ps->levelshead++ = 0;
  		    }
  		  if (!ps->levels[litlevel])
  		    {
  		      if (ps->dusedhead >= ps->eodused)
  			ENLARGE (ps->dused, ps->dusedhead, ps->eodused);
  		      assert (ps->dusedhead < ps->eodused);
  		      *ps->dusedhead++ = litlevel;
  		      ps->levels[litlevel] = 1;
  		      glue++;
  		    }
  		}
  	      else
  		glue++;
  	    }
  
  	  while (ps->dusedhead > ps->dused) 
  	    {
  	      litlevel = *--ps->dusedhead;
  	      assert (ps->levels + litlevel < ps->levelshead);
  	      assert (ps->levels[litlevel]);
  	      ps->levels[litlevel] = 0;
  	    }
  	}
  
        assert (glue <= MAXGLUE);
        res->glue = glue;
  
  #if !defined(NDEBUG) && defined(TRACE)
        if (ps->trace)
  	assert (CLS2IDX (res) == idx);
  #endif
        if (learned)
  	*ps->lhead++ = res;
        else
  	*ps->ohead++ = res;
  
  #if !defined(NDEBUG) && defined(TRACE)
        if (ps->trace && learned)
  	assert (ps->zhead - ps->zhains == ps->lhead - ps->lclauses);
  #endif
        assert (ps->lhead != ps->oclauses);		/* ditto */
      }
  
    if (learned && ps->rup)
      {
        if (!ps->rupstarted)
  	{
  	  write_rup_header (ps, ps->rup);
  	  ps->rupstarted = 1;
  	}
      }
  
    num_true = num_undef = num_false = 0;
  
    q = res->lits;
    for (p = ps->added; p < ps->ahead; p++)
      {
        lit = *p;
        *q++ = lit;
  
        if (learned && ps->rup)
  	fprintf (ps->rup, "%d ", LIT2INT (lit));
  
        val = lit->val;
  
        num_true += (val == TRUE);
        num_undef += (val == UNDEF);
        num_false += (val == FALSE);
      }
    assert (num_false + num_true + num_undef == size);
  
    if (learned && ps->rup)
      fputs ("0\n", ps->rup);
  
    ps->ahead = ps->added;		/* reset */
  
    if (!reentered)				// TODO merge
    if (size > 0)
      {
        assert (size <= 2 || !reentered);		// TODO remove
        connect_head_tail (ps, res->lits[0], res);
        if (size > 1)
  	connect_head_tail (ps, res->lits[1], res);
      }
  
    if (size == 0)
      {
        if (!ps->mtcls)
  	ps->mtcls = res;
      }
  
  #ifdef NO_BINARY_CLAUSES
    if (size != 2)
  #endif
  #ifndef NDEBUG
      res->connected = 1;
  #endif
  
    LOG ( fprintf (ps->out, "%s%s ", ps->prefix, learned ? "learned" : "original");
          dumpclsnl (ps, res));
  
    /* Shrink clause by resolving it against top level assignments.
     */
    if (!ps->LEVEL && num_false > 0)
      {
        assert (ps->ahead == ps->added);
        assert (ps->rhead == ps->resolved);
  
        count_resolved = 1;
        add_antecedent (ps, res);
  
        end = end_of_lits (res);
        for (p = res->lits; p < end; p++)
  	{
  	  lit = *p;
  	  v = LIT2VAR (lit);
  	  use_var (ps, v);
  
  	  if (lit->val == FALSE)
  	    {
  	      add_antecedent (ps, v->reason);
  	      count_resolved++;
  	    }
  	  else
  	    add_lit (ps, lit);
  	}
  
        assert (count_resolved >= 2);
  
        learned = 1;
  #ifdef NO_BINARY_CLAUSES
        if (res == &ps->impl)
  	resetimpl (ps);
  #endif
        reentered = 1;
        goto REENTER;		/* and return simplified clause */
      }
  
    if (!num_true && num_undef == 1)	/* unit clause */
      {
        lit = 0;
        for (p = res->lits; p < res->lits + size; p++)
  	{
  	  if ((*p)->val == UNDEF)
  	    lit = *p;
  
  	  v = LIT2VAR (*p);
  	  use_var (ps, v);
  	}
        assert (lit);
  
        reason = res;
  #ifdef NO_BINARY_CLAUSES
        if (size == 2)
          {
  	  Lit * other = res->lits[0];
  	  if (other == lit)
  	    other = res->lits[1];
  
  	  assert (other->val == FALSE);
  	  reason = LIT2REASON (NOTLIT (other));
  	}
  #endif
        assign_forced (ps, lit, reason);
        num_true++;
      }
  
    if (num_false == size && !ps->conflict)
      {
  #ifdef NO_BINARY_CLAUSES
        if (res == &ps->impl)
  	ps->conflict = setcimpl (ps, res->lits[0], res->lits[1]);
        else
  #endif
        ps->conflict = res;
      }
  
    if (!learned && !num_true && num_undef)
      incjwh (ps, res);
  
  #ifdef NO_BINARY_CLAUSES
    if (res == &ps->impl)
      resetimpl (ps);
  #endif
    return res;
  }
  
  static int
  trivial_clause (PS * ps)
  {
    Lit **p, **q, *prev;
    Var *v;
  
    SORT (Lit *, cmp_ptr, ps->added,  ps->ahead - ps->added);
  
    prev = 0;
    q = ps->added;
    for (p = q; p < ps->ahead; p++)
      {
        Lit *this = *p;
  
        v = LIT2VAR (this);
  
        if (prev == this)		/* skip repeated literals */
  	continue;
  
        /* Top level satisfied ? 
         */
        if (this->val == TRUE && !v->level)
  	 return 1;
  
        if (prev == NOTLIT (this))/* found pair of dual literals */
  	return 1;
  
        *q++ = prev = this;
      }
  
    ps->ahead = q;			/* shrink */
  
    return 0;
  }
  
  static void
  simplify_and_add_original_clause (PS * ps, int context_index)
  {
    ABORTIF(context_index > ps->clshead - ps->CLS, "Illegal context index (greater than largest context index)");
    ABORTIF(context_index < 0, "Illegal context index (less than 0)");
  #ifdef NO_BINARY_CLAUSES
    Cls * c;
  #endif
    if (trivial_clause (ps))
      {
        ps->ahead = ps->added;
  
        if (ps->ohead == ps->eoo)
  	ENLARGE (ps->oclauses, ps->ohead, ps->eoo);
  
        *ps->ohead++ = 0;
  
        ps->addedclauses++;
        ps->oadded++;
      }
    else
      {
        if (context_index != 0)
  	add_lit (ps, NOTLIT (ps->CLS[context_index-1]));
  
  #ifdef NO_BINARY_CLAUSES
        c = 
  #endif
        add_simplified_clause (ps, 0);
  #ifdef NO_BINARY_CLAUSES
        if (c == &ps->impl) assert (!ps->implvalid);
  #endif
      }
  }
  
  #ifndef NADC
  
  static void
  add_ado (PS * ps)
  {
    unsigned len = ps->ahead - ps->added;
    Lit ** ado, ** p, ** q, *lit;
    Var * v, * u;
  
  #ifdef TRACE
    assert (!ps->trace);
  #endif
  
    ABORTIF (ps->ados < ps->hados && llength (ps->ados[0]) != len,
             "internal: non matching all different constraint object lengths");
  
    if (ps->hados == ps->eados)
      ENLARGE (ps->ados, ps->hados, ps->eados);
  
    NEWN (ado, len + 1);
    *ps->hados++ = ado;
  
    p = ps->added;
    q = ado;
    u = 0;
    while (p < ps->ahead)
      {
        lit = *p++;
        v = LIT2VAR (lit);
        ABORTIF (v->inado, 
                 "internal: variable in multiple all different objects");
        v->inado = ado;
        if (!u && !lit->val)
  	u = v;
        *q++ = lit;
      }
  
    assert (q == ado + len);
    *q++ = 0;
  
    /* TODO simply do a conflict test as in propado */
  
    ABORTIF (!u,
      "internal: "
      "adding fully instantiated all different object not implemented yet");
  
    assert (u);
    assert (u->inado == ado);
    assert (!u->ado);
    u->ado = ado;
  
    ps->ahead = ps->added;
  }
  
  #endif
  
  static void
  hdown (PS * ps, Rnk * r)
  {
    unsigned end, rpos, cpos, opos;
    Rnk *child, *other;
  
    assert (r->pos > 0);
    assert (ps->heap[r->pos] == r);
  
    end = ps->hhead - ps->heap;
    rpos = r->pos;
  
    for (;;)
      {
        cpos = 2 * rpos;
        if (cpos >= end)
  	break;
  
        opos = cpos + 1;
        child = ps->heap[cpos];
  
        if (cmp_rnk (r, child) < 0)
  	{
  	  if (opos < end)
  	    {
  	      other = ps->heap[opos];
  
  	      if (cmp_rnk (child, other) < 0)
  		{
  		  child = other;
  		  cpos = opos;
  		}
  	    }
  	}
        else if (opos < end)
  	{
  	  child = ps->heap[opos];
  
  	  if (cmp_rnk (r, child) >= 0)
  	    break;
  
  	  cpos = opos;
  	}
        else
  	break;
  
        ps->heap[rpos] = child;
        child->pos = rpos;
        rpos = cpos;
      }
  
    r->pos = rpos;
    ps->heap[rpos] = r;
  }
  
  static Rnk *
  htop (PS * ps)
  {
    assert (ps->hhead > ps->heap + 1);
    return ps->heap[1];
  }
  
  static Rnk *
  hpop (PS * ps)
  {
    Rnk *res, *last;
    unsigned end;
  
    assert (ps->hhead > ps->heap + 1);
  
    res = ps->heap[1];
    res->pos = 0;
  
    end = --ps->hhead - ps->heap;
    if (end == 1)
      return res;
  
    last = ps->heap[end];
  
    ps->heap[last->pos = 1] = last;
    hdown (ps, last);
  
    return res;
  }
  
  inline static void
  hpush (PS * ps, Rnk * r)
  {
    assert (!r->pos);
  
    if (ps->hhead == ps->eoh)
      ENLARGE (ps->heap, ps->hhead, ps->eoh);
  
    r->pos = ps->hhead++ - ps->heap;
    ps->heap[r->pos] = r;
    hup (ps, r);
  }
  
  static void
  fix_trail_lits (PS * ps, long delta)
  {
    Lit **p;
    for (p = ps->trail; p < ps->thead; p++)
      *p += delta;
  }
  
  #ifdef NO_BINARY_CLAUSES
  static void
  fix_impl_lits (PS * ps, long delta)
  {
    Ltk * s;
    Lit ** p;
  
    for (s = ps->impls + 2; s <= ps->impls + 2 * ps->max_var + 1; s++)
      for (p = s->start; p < s->start + s->count; p++)
        *p += delta;
  }
  #endif
  
  static void
  fix_clause_lits (PS * ps, long delta)
  {
    Cls **p, *clause;
    Lit **q, *lit, **eol;
  
    for (p = SOC; p != EOC; p = NXC (p))
      {
        clause = *p;
        if (!clause)
  	continue;
  
        q = clause->lits;
        eol = end_of_lits (clause);
        while (q < eol)
  	{
  	  assert (q - clause->lits <= (int) clause->size);
  	  lit = *q;
  	  lit += delta;
  	  *q++ = lit;
  	}
      }
  }
  
  static void
  fix_added_lits (PS * ps, long delta)
  {
    Lit **p;
    for (p = ps->added; p < ps->ahead; p++)
      *p += delta;
  }
  
  static void
  fix_assumed_lits (PS * ps, long delta)
  {
    Lit **p;
    for (p = ps->als; p < ps->alshead; p++)
      *p += delta;
  }
  
  static void
  fix_cls_lits (PS * ps, long delta)
  {
    Lit **p;
    for (p = ps->CLS; p < ps->clshead; p++)
      *p += delta;
  }
  
  static void
  fix_heap_rnks (PS * ps, long delta)
  {
    Rnk **p;
  
    for (p = ps->heap + 1; p < ps->hhead; p++)
      *p += delta;
  }
  
  #ifndef NADC
  
  static void
  fix_ado (long delta, Lit ** ado)
  {
    Lit ** p;
    for (p = ado; *p; p++)
      *p += delta;
  }
  
  static void
  fix_ados (PS * ps, long delta)
  {
    Lit *** p;
  
    for (p = ps->ados; p < ps->hados; p++)
      fix_ado (delta, *p);
  }
  
  #endif
  
  static void
  enlarge (PS * ps, unsigned new_size_vars)
  {
    long rnks_delta, lits_delta;
    Lit *old_lits = ps->lits;
    Rnk *old_rnks = ps->rnks;
  
    RESIZEN (ps->lits, 2 * ps->size_vars, 2 * new_size_vars);
    RESIZEN (ps->jwh, 2 * ps->size_vars, 2 * new_size_vars);
    RESIZEN (ps->htps, 2 * ps->size_vars, 2 * new_size_vars);
  #ifndef NDSC
    RESIZEN (ps->dhtps, 2 * ps->size_vars, 2 * new_size_vars);
  #endif
    RESIZEN (ps->impls, 2 * ps->size_vars, 2 * new_size_vars);
    RESIZEN (ps->vars, ps->size_vars, new_size_vars);
    RESIZEN (ps->rnks, ps->size_vars, new_size_vars);
  
    if ((lits_delta = ps->lits - old_lits))
      {
        fix_trail_lits (ps, lits_delta);
        fix_clause_lits (ps, lits_delta);
        fix_added_lits (ps, lits_delta);
        fix_assumed_lits (ps, lits_delta);
        fix_cls_lits (ps, lits_delta);
  #ifdef NO_BINARY_CLAUSES
        fix_impl_lits (ps, lits_delta);
  #endif
  #ifndef NADC
        fix_ados (ps, lits_delta);
  #endif
      }
  
    if ((rnks_delta = ps->rnks - old_rnks))
      {
        fix_heap_rnks (ps, rnks_delta);
      }
  
    assert (ps->mhead == ps->marked);
  
    ps->size_vars = new_size_vars;
  }
  
  static void
  unassign (PS * ps, Lit * lit)
  {
    Cls *reason;
    Var *v;
    Rnk *r;
  
    assert (lit->val == TRUE);
  
    LOG ( fprintf (ps->out, "%sunassign %d\n", ps->prefix, LIT2INT (lit)));
  
    v = LIT2VAR (lit);
    reason = v->reason;
  
  #ifdef NO_BINARY_CLAUSES
    assert (reason != &ps->impl);
    if (ISLITREASON (reason))
      {
        /* DO NOTHING */
      }
    else
  #endif
    if (reason)
      {
        assert (reason->locked);
        reason->locked = 0;
        if (reason->learned && reason->size > 2)
  	{
  	  assert (ps->llocked > 0);
  	  ps->llocked--;
  	}
      }
  
    lit->val = UNDEF;
    NOTLIT (lit)->val = UNDEF;
  
    r = VAR2RNK (v);
    if (!r->pos)
      hpush (ps, r);
  
  #ifndef NDSC
    {
      Cls * p, * next, ** q;
  
      q = LIT2DHTPS (lit);
      p = *q;
      *q = 0;
  
      while (p)
        {
  	Lit * other = p->lits[0];
  
  	if (other == lit)
  	  {
  	    other = p->lits[1];
  	    q = p->next + 1;
  	  }
  	else
  	  {
  	    assert (p->lits[1] == lit);
  	    q = p->next;
  	  }
  
  	next = *q;
  	*q = *LIT2HTPS (other);
  	*LIT2HTPS (other) = p;
  	p = next;
        }
    }
  #endif
  
  #ifndef NADC
    if (v->adotabpos)
      {
        assert (ps->nadotab);
        assert (*v->adotabpos == v->ado);
  
        *v->adotabpos = 0;
        v->adotabpos = 0;
  
        ps->nadotab--;
      }
  #endif
  }
  
  static Cls *
  var2reason (PS * ps, Var * var)
  {
    Cls * res = var->reason;
  #ifdef NO_BINARY_CLAUSES
    Lit * this, * other;
    if (ISLITREASON (res))
      {
        this = VAR2LIT (var);
        if (this->val == FALSE)
  	this = NOTLIT (this);
  
        other = REASON2LIT (res);
        assert (other->val == TRUE);
        assert (this->val == TRUE);
        res = setimpl (ps, NOTLIT (other), this);
      }
  #else
    (void) ps;
  #endif
    return res;
  }
  
  static void
  mark_clause_to_be_collected (Cls * c)
  {
    assert (!c->collect);
    c->collect = 1;
  }
  
  static void
  undo (PS * ps, unsigned new_level)
  {
    Lit *lit;
    Var *v;
  
    while (ps->thead > ps->trail)
      {
        lit = *--ps->thead;
        v = LIT2VAR (lit);
        if (v->level == new_level)
  	{
  	  ps->thead++;		/* fix pre decrement */
  	  break;
  	}
  
        unassign (ps, lit);
      }
  
    ps->LEVEL = new_level;
    ps->ttail = ps->thead;
    ps->ttail2 = ps->thead;
  #ifndef NADC
    ps->ttailado = ps->thead;
  #endif
  
  #ifdef NO_BINARY_CLAUSES
    if (ps->conflict == &ps->cimpl)
      resetcimpl (ps);
  #endif
  #ifndef NADC
    if (ps->conflict && ps->conflict == ps->adoconflict)
      resetadoconflict (ps);
  #endif
    ps->conflict = ps->mtcls;
    if (ps->LEVEL < ps->adecidelevel)
      {
        assert (ps->als < ps->alshead);
        ps->adecidelevel = 0;
        ps->alstail = ps->als;
      }
    LOG ( fprintf (ps->out, "%sback to level %u\n", ps->prefix, ps->LEVEL));
  }
  
  #ifndef NDEBUG
  
  static int
  clause_satisfied (Cls * c)
  {
    Lit **p, **eol, *lit;
  
    eol = end_of_lits (c);
    for (p = c->lits; p < eol; p++)
      {
        lit = *p;
        if (lit->val == TRUE)
  	return 1;
      }
  
    return 0;
  }
  
  static void
  original_clauses_satisfied (PS * ps)
  {
    Cls **p, *c;
  
    for (p = ps->oclauses; p < ps->ohead; p++)
      {
        c = *p;
  
        if (!c)
  	continue;
  
        if (c->learned)
  	continue;
  
        assert (clause_satisfied (c));
      }
  }
  
  static void
  assumptions_satisfied (PS * ps)
  {
    Lit *lit, ** p;
  
    for (p = ps->als; p < ps->alshead; p++)
      {
        lit = *p;
        assert (lit->val == TRUE);
      }
  }
  
  #endif
  
  static void
  sflush (PS * ps)
  {
    double now = picosat_time_stamp ();
    double delta = now - ps->entered;
    delta = (delta < 0) ? 0 : delta;
    ps->seconds += delta;
    ps->entered = now;
  }
  
  static double
  mb (PS * ps)
  {
    return ps->current_bytes / (double) (1 << 20);
  }
  
  static double
  avglevel (PS * ps)
  {
    return ps->decisions ? ps->levelsum / ps->decisions : 0.0;
  }
  
  static void
  rheader (PS * ps)
  {
    assert (ps->lastrheader <= ps->reports);
  
    if (ps->lastrheader == ps->reports)
      return;
  
    ps->lastrheader = ps->reports;
  
     fprintf (ps->out, "%s\n", ps->prefix);
     fprintf (ps->out, "%s %s\n", ps->prefix, ps->rline[0]);
     fprintf (ps->out, "%s %s\n", ps->prefix, ps->rline[1]);
     fprintf (ps->out, "%s\n", ps->prefix);
  }
  
  static unsigned
  dynamic_flips_per_assignment_per_mille (PS * ps)
  {
    assert (FFLIPPEDPREC >= 1000);
    return ps->sdflips / (FFLIPPEDPREC / 1000);
  }
  
  #ifdef NLUBY
  
  static int
  high_agility (PS * ps)
  {
    return dynamic_flips_per_assignment_per_mille (ps) >= 200;
  }
  
  static int
  very_high_agility (PS * ps)
  {
    return dynamic_flips_per_assignment_per_mille (ps) >= 250;
  }
  
  #else
  
  static int
  medium_agility (PS * ps)
  {
    return dynamic_flips_per_assignment_per_mille (ps) >= 230;
  }
  
  #endif
  
  static void
  relemdata (PS * ps)
  {
    char *p;
    int x;
  
    if (ps->reports < 0)
      {
        /* strip trailing white space 
         */
        for (x = 0; x <= 1; x++)
  	{
  	  p = ps->rline[x] + strlen (ps->rline[x]);
  	  while (p-- > ps->rline[x])
  	    {
  	      if (*p != ' ')
  		break;
  
  	      *p = 0;
  	    }
  	}
  
        rheader (ps);
      }
    else
      fputc ('\n', ps->out);
  
    ps->RCOUNT = 0;
  }
  
  static void
  relemhead (PS * ps, const char * name, int fp, double val)
  {
    int x, y, len, size;
    const char *fmt;
    unsigned tmp, e;
  
    if (ps->reports < 0)
      {
        x = ps->RCOUNT & 1;
        y = (ps->RCOUNT / 2) * 12 + x * 6;
  
        if (ps->RCOUNT == 1)
  	sprintf (ps->rline[1], "%6s", "");
  
        len = strlen (name);
        while (ps->szrline <= len + y + 1)
  	{
  	  size = ps->szrline ? 2 * ps->szrline : 128;
  	  ps->rline[0] = resize (ps, ps->rline[0], ps->szrline, size);
  	  ps->rline[1] = resize (ps, ps->rline[1], ps->szrline, size);
  	  ps->szrline = size;
  	}
  
        fmt = (len <= 6) ? "%6s%10s" : "%-10s%4s";
        sprintf (ps->rline[x] + y, fmt, name, "");
      }
    else if (val < 0)
      {
        assert (fp);
  
        if (val > -100 && (tmp = val * 10.0 - 0.5) > -1000.0)
  	{
  	   fprintf (ps->out, "-%4.1f ", -tmp / 10.0);
  	}
        else
  	{
  	  tmp = -val / 10.0 + 0.5;
  	  e = 1;
  	  while (tmp >= 100)
  	    {
  	      tmp /= 10;
  	      e++;
  	    }
  
  	   fprintf (ps->out, "-%2ue%u ", tmp, e);
  	}
      }
    else
      {
        if (fp && val < 1000 && (tmp = val * 10.0 + 0.5) < 10000)
  	{
  	   fprintf (ps->out, "%5.1f ", tmp / 10.0);
  	}
        else if (!fp && (tmp = val) < 100000)
  	{
  	   fprintf (ps->out, "%5u ", tmp);
  	}
        else
  	{
  	  tmp = val / 10.0 + 0.5;
  	  e = 1;
  
  	  while (tmp >= 1000)
  	    {
  	      tmp /= 10;
  	      e++;
  	    }
  
  	   fprintf (ps->out, "%3ue%u ", tmp, e);
  	}
      }
  
    ps->RCOUNT++;
  }
  
  inline static void
  relem (PS * ps, const char *name, int fp, double val)
  {
    if (name)
      relemhead (ps, name, fp, val);
    else
      relemdata (ps);
  }
  
  static unsigned
  reduce_limit_on_lclauses (PS * ps)
  {
    unsigned res = ps->lreduce;
    res += ps->llocked;
    return res;
  }
  
  static void
  report (PS * ps, int replevel, char type)
  {
    int rounds;
  
  #ifdef RCODE
    (void) type;
  #endif
  
    if (ps->verbosity < replevel)
      return;
  
    sflush (ps);
  
    if (!ps->reports)
      ps->reports = -1;
  
    for (rounds = (ps->reports < 0) ? 2 : 1; rounds; rounds--)
      {
        if (ps->reports >= 0)
  	 fprintf (ps->out, "%s%c ", ps->prefix, type);
  
        relem (ps, "seconds", 1, ps->seconds);
        relem (ps, "level", 1, avglevel (ps));
        assert (ps->fixed <=  ps->max_var);
        relem (ps, "variables", 0, ps->max_var - ps->fixed);
        relem (ps, "used", 1, PERCENT (ps->vused, ps->max_var));
        relem (ps, "original", 0, ps->noclauses);
        relem (ps, "conflicts", 0, ps->conflicts);
        // relem (ps, "decisions", 0, ps->decisions);
        // relem (ps, "conf/dec", 1, PERCENT(ps->conflicts,ps->decisions));
        // relem (ps, "limit", 0, reduce_limit_on_lclauses (ps));
        relem (ps, "learned", 0, ps->nlclauses);
        // relem (ps, "limit", 1, PERCENT (ps->nlclauses, reduce_limit_on_lclauses (ps)));
        relem (ps, "limit", 0, ps->lreduce);
  #ifdef STATS
        relem (ps, "learning", 1, PERCENT (ps->llused, ps->lladded));
  #endif
        relem (ps, "agility", 1, dynamic_flips_per_assignment_per_mille (ps) / 10.0);
        // relem (ps, "original", 0, ps->noclauses);
        relem (ps, "MB", 1, mb (ps));
        // relem (ps, "lladded", 0, ps->lladded);
        // relem (ps, "llused", 0, ps->llused);
  
        relem (ps, 0, 0, 0);
  
        ps->reports++;
      }
  
    /* Adapt this to the number of rows in your terminal.
     */
    #define ROWS 25
  
    if (ps->reports % (ROWS - 3) == (ROWS - 4))
      rheader (ps);
  
    fflush (ps->out);
  }
  
  static int
  bcp_queue_is_empty (PS * ps)
  {
    if (ps->ttail != ps->thead)
      return 0;
  
    if (ps->ttail2 != ps->thead)
      return 0;
  
  #ifndef NADC
    if (ps->ttailado != ps->thead)
      return 0;
  #endif
  
    return 1;
  }
  
  static int
  satisfied (PS * ps)
  {
    assert (!ps->mtcls);
    assert (!ps->failed_assumption);
    if (ps->alstail < ps->alshead)
      return 0;
    assert (!ps->conflict);
    assert (bcp_queue_is_empty (ps));
    return ps->thead == ps->trail + ps->max_var;	/* all assigned */
  }
  
  static void
  vrescore (PS * ps)
  {
    Rnk *p, *eor = ps->rnks + ps->max_var;
    for (p = ps->rnks + 1; p <= eor; p++)
      if (p->score != INFFLT)
        p->score = mulflt (p->score, ps->ilvinc);
    ps->vinc = mulflt (ps->vinc, ps->ilvinc);;
  #ifdef VISCORES
    ps->nvinc = mulflt (ps->nvinc, ps->lscore);;
  #endif
  }
  
  static void
  inc_score (PS * ps, Var * v)
  {
    Flt score;
    Rnk *r;
  
  #ifndef NFL
    if (ps->simplifying)
      return;
  #endif
  
    if (!v->level)
      return;
  
    if (v->internal)
      return;
  
    r = VAR2RNK (v);
    score = r->score;
  
    assert (score != INFFLT);
  
    score = addflt (score, ps->vinc);
    assert (score < INFFLT);
    r->score = score;
    if (r->pos > 0)
      hup (ps, r);
  
    if (score > ps->lscore)
      vrescore (ps);
  }
  
  static void
  inc_activity (PS * ps, Cls * c)
  {
    Act *p;
  
    if (!c->learned)
      return;
  
    if (c->size <= 2)
      return;
  
    p = CLS2ACT (c);
    *p = addflt (*p, ps->cinc);
  }
  
  static unsigned
  hashlevel (unsigned l)
  {
    return 1u << (l & 31);
  }
  
  static void
  push (PS * ps, Var * v)
  {
    if (ps->dhead == ps->eod)
      ENLARGE (ps->dfs, ps->dhead, ps->eod);
  
    *ps->dhead++ = v;
  }
  
  static Var * 
  pop (PS * ps)
  {
    assert (ps->dfs < ps->dhead);
    return *--ps->dhead;
  }
  
  static void
  analyze (PS * ps)
  {
    unsigned open, minlevel, siglevels, l, old, i, orig;
    Lit *this, *other, **p, **q, **eol;
    Var *v, *u, **m, *start, *uip;
    Cls *c;
  
    assert (ps->conflict);
  
    assert (ps->ahead == ps->added);
    assert (ps->mhead == ps->marked);
    assert (ps->rhead == ps->resolved);
  
    /* First, search for First UIP variable and mark all resolved variables.
     * At the same time determine the minimum decision level involved.
     * Increase activities of resolved variables.
     */
    q = ps->thead;
    open = 0;
    minlevel = ps->LEVEL;
    siglevels = 0;
    uip = 0;
  
    c = ps->conflict;
  
    for (;;)
      {
        add_antecedent (ps, c);
        inc_activity (ps, c);
        eol = end_of_lits (c);
        for (p = c->lits; p < eol; p++)
  	{
  	  other = *p;
  
  	  if (other->val == TRUE)
  	    continue;
  
  	  assert (other->val == FALSE);
  
  	  u = LIT2VAR (other);
  	  if (u->mark)
  	    continue;
  	  
  	  u->mark = 1;
  	  inc_score (ps, u);
  	  use_var (ps, u);
  
  	  if (u->level == ps->LEVEL)
  	    {
  	      open++;
  	    }
  	  else 
  	    {
  	      push_var_as_marked (ps, u);
  
  	      if (u->level)
  		{
  		  /* The statistics counter 'nonminimizedllits' sums up the
  		   * number of literals that would be added if only the
  		   * 'first UIP' scheme for learned clauses would be used
  		   * and no clause minimization.
  		   */
  		  ps->nonminimizedllits++;
  
  		  if (u->level < minlevel)
  		    minlevel = u->level;
  
  		  siglevels |= hashlevel (u->level);
  		}
  	      else
  		{
  		  assert (!u->level);
  		  assert (u->reason);
  		}
  	    }
  	}
  
        do
  	{
  	  if (q == ps->trail)
  	    {
  	      uip = 0;
  	      goto DONE_FIRST_UIP;
  	    }
  
  	  this = *--q;
  	  uip = LIT2VAR (this);
  	}
        while (!uip->mark);
  
        uip->mark = 0;
  
        c = var2reason (ps, uip);
  #ifdef NO_BINARY_CLAUSES
        if (c == &ps->impl)
  	resetimpl (ps);
  #endif
       open--;
       if ((!open && ps->LEVEL) || !c)
  	break;
  
       assert (c);
      }
  
  DONE_FIRST_UIP:
  
    if (uip)
      {
        assert (ps->LEVEL);
        this = VAR2LIT (uip);
        this += (this->val == TRUE);
        ps->nonminimizedllits++;
        ps->minimizedllits++;
        add_lit (ps, this);
  #ifdef STATS
        if (uip->reason)
  	ps->uips++;
  #endif
      }
    else
      assert (!ps->LEVEL);
  
    /* Second, try to mark more intermediate variables, with the goal to
     * minimize the conflict clause.  This is a DFS from already marked
     * variables backward through the implication graph.  It tries to reach
     * other marked variables.  If the search reaches an unmarked decision
     * variable or a variable assigned below the minimum level of variables in
     * the first uip learned clause or a level on which no variable has been
     * marked, then the variable from which the DFS is started is not
     * redundant.  Otherwise the start variable is redundant and will
     * eventually be removed from the learned clause in step 4.  We initially
     * implemented BFS, but then profiling revelead that this step is a bottle
     * neck for certain incremental applications.  After switching to DFS this
     * hot spot went away.
     */
    orig = ps->mhead - ps->marked;
    for (i = 0; i < orig; i++)
      {
        start = ps->marked[i];
  
        assert (start->mark);
        assert (start != uip);
        assert (start->level < ps->LEVEL);
  
        if (!start->reason)
  	continue;
  
        old = ps->mhead - ps->marked;
        assert (ps->dhead == ps->dfs);
        push (ps, start);
  
        while (ps->dhead > ps->dfs)
  	{
  	  u = pop (ps);
  	  assert (u->mark);
  
  	  c = var2reason (ps, u);
  #ifdef NO_BINARY_CLAUSES
  	  if (c == &ps->impl)
  	    resetimpl (ps);
  #endif
  	  if (!c || 
  	      ((l = u->level) && 
  	       (l < minlevel || ((hashlevel (l) & ~siglevels)))))
  	    {
  	      while (ps->mhead > ps->marked + old)	/* reset all marked */
  		(*--ps->mhead)->mark = 0;
  
  	      ps->dhead = ps->dfs;		/* and DFS stack */
  	      break;
  	    }
  
  	  eol = end_of_lits (c);
  	  for (p = c->lits; p < eol; p++)
  	    {
  	      v = LIT2VAR (*p);
  	      if (v->mark)
  		continue;
  
  	      mark_var (ps, v);
  	      push (ps, v);
  	    }
  	}
      }
  
    for (m = ps->marked; m < ps->mhead; m++)
      {
        v = *m;
  
        assert (v->mark);
        assert (!v->resolved);
  
        use_var (ps, v);
  
        c = var2reason (ps, v);
        if (!c)
  	continue;
  
  #ifdef NO_BINARY_CLAUSES
        if (c == &ps->impl)
  	resetimpl (ps);
  #endif
        eol = end_of_lits (c);
        for (p = c->lits; p < eol; p++)
  	{
  	  other = *p;
  
  	  u = LIT2VAR (other);
  	  if (!u->level)
  	    continue;
  
  	  if (!u->mark)		/* 'MARKTEST' */
  	    break;
  	}
  
        if (p != eol)
  	continue;
  
        add_antecedent (ps, c);
        v->resolved = 1;
      }
  
    for (m = ps->marked; m < ps->mhead; m++)
      {
        v = *m;
  
        assert (v->mark);
        v->mark = 0;
  
        if (v->resolved)
  	{
  	  v->resolved = 0;
  	  continue;
  	}
  
        this = VAR2LIT (v);
        if (this->val == TRUE)
  	this++;			/* actually NOTLIT */
  
        add_lit (ps, this);
        ps->minimizedllits++;
      }
  
    assert (ps->ahead <= ps->eoa);
    assert (ps->rhead <= ps->eor);
  
    ps->mhead = ps->marked;
  }
  
  static void
  fanalyze (PS * ps)
  {
    Lit ** eol, ** p, * lit;
    Cls * c, * reason;
    Var * v, * u;
    int next;
  
  #ifndef RCODE
    double start = picosat_time_stamp ();
  #endif
  
    assert (ps->failed_assumption);
    assert (ps->failed_assumption->val == FALSE);
  
    v = LIT2VAR (ps->failed_assumption);
    reason = var2reason (ps, v);
    if (!reason) return;
  #ifdef NO_BINARY_CLAUSES
    if (reason == &ps->impl)
      resetimpl (ps);
  #endif
  
    eol = end_of_lits (reason);
    for (p = reason->lits; p != eol; p++)
      {
        lit = *p;
        u = LIT2VAR (lit);
        if (u == v) continue;
        if (u->reason) break;
      }
    if (p == eol) return;
  
    assert (ps->ahead == ps->added);
    assert (ps->mhead == ps->marked);
    assert (ps->rhead == ps->resolved);
  
    next = 0;
    mark_var (ps, v);
    add_lit (ps, NOTLIT (ps->failed_assumption));
  
    do
      {
        v = ps->marked[next++];
        use_var (ps, v);
        if (v->reason)
  	{
  	  reason = var2reason (ps, v);
  #ifdef NO_BINARY_CLAUSES
  	  if (reason == &ps->impl)
  	    resetimpl (ps);
  #endif
  	  add_antecedent (ps, reason);
  	  eol = end_of_lits (reason);
  	  for (p = reason->lits; p != eol; p++)
  	    {
  	      lit = *p;
  	      u = LIT2VAR (lit);
  	      if (u == v) continue;
  	      if (u->mark) continue;
  	      mark_var (ps, u);
  	    }
  	}
        else
  	{
  	  lit = VAR2LIT (v);
  	  if (lit->val == TRUE) lit = NOTLIT (lit);
  	  add_lit (ps, lit);
  	}
      } 
    while (ps->marked + next < ps->mhead);
  
    c = add_simplified_clause (ps, 1);
    v = LIT2VAR (ps->failed_assumption);
    reason = v->reason;
  #ifdef NO_BINARY_CLAUSES
    if (!ISLITREASON (reason))
  #endif
      {
        assert (reason->locked);
        reason->locked = 0;
        if (reason->learned && reason->size > 2)
  	{
  	  assert (ps->llocked > 0);
  	  ps->llocked--;
  	}
      }
  
  #ifdef NO_BINARY_CLAUSES
    if (c == &ps->impl)
      {
        c = impl2reason (ps, NOTLIT (ps->failed_assumption));
      }
    else
  #endif
      {
        assert (c->learned);
        assert (!c->locked);
        c->locked = 1;
        if (c->size > 2)
  	{
  	  ps->llocked++;
  	  assert (ps->llocked > 0);
  	}
      }
  
    v->reason = c;
  
    while (ps->mhead > ps->marked)
      (*--ps->mhead)->mark = 0;
  
    if (ps->verbosity)
       fprintf (ps->out, "%sfanalyze took %.1f seconds\n", 
  	     ps->prefix, picosat_time_stamp () - start);
  }
  
  /* Propagate assignment of 'this' to 'FALSE' by visiting all binary clauses in
   * which 'this' occurs.
   */
  inline static void
  prop2 (PS * ps, Lit * this)
  {
  #ifdef NO_BINARY_CLAUSES
    Lit ** l, ** start;
    Ltk * lstk;
  #else
    Cls * c, ** p;
    Cls * next;
  #endif
    Lit * other;
    Val tmp;
  
    assert (this->val == FALSE);
  
  #ifdef NO_BINARY_CLAUSES
    lstk = LIT2IMPLS (this);
    start = lstk->start;
    l = start + lstk->count;
    while (l != start)
      {
        /* The counter 'visits' is the number of clauses that are
         * visited during propagations of assignments.
         */
        ps->visits++;
  #ifdef STATS
        ps->bvisits++;
  #endif
        other = *--l;
        tmp = other->val;
  
        if (tmp == TRUE)
  	{
  #ifdef STATS
  	  ps->othertrue++;
  	  ps->othertrue2++;
  	  if (LIT2VAR (other)->level < ps->LEVEL)
  	    ps->othertrue2u++;
  #endif
  	  continue;
  	}
  
        if (tmp != FALSE)
  	{
  	  assign_forced (ps, other, LIT2REASON (NOTLIT(this)));
  	  continue;
  	}
  
        if (ps->conflict == &ps->cimpl)
  	resetcimpl (ps);
        ps->conflict = setcimpl (ps, this, other);
      }
  #else
    /* Traverse all binary clauses with 'this'.  Head/Tail pointers for binary
     * clauses do not have to be modified here.
     */
    p = LIT2IMPLS (this);
    for (c = *p; c; c = next)
      {
        ps->visits++;
  #ifdef STATS
        ps->bvisits++;
  #endif
        assert (!c->collect);
  #ifdef TRACE
        assert (!c->collected);
  #endif
        assert (c->size == 2);
        
        other = c->lits[0];
        if (other == this)
  	{
  	  next = c->next[0];
  	  other = c->lits[1];
  	}
        else
  	next = c->next[1];
  
        tmp = other->val;
  
        if (tmp == TRUE)
  	{
  #ifdef STATS
  	  ps->othertrue++;
  	  ps->othertrue2++;
  	  if (LIT2VAR (other)->level < ps->LEVEL)
  	    ps->othertrue2u++;
  #endif
  	  continue;
  	}
  
        if (tmp == FALSE)
  	ps->conflict = c;
        else
  	assign_forced (ps, other, c);	/* unit clause */
      }
  #endif /* !defined(NO_BINARY_CLAUSES) */
  }
  
  #ifndef NDSC
  static int
  should_disconnect_head_tail (PS * ps, Lit * lit)
  {
    unsigned litlevel;
    Var * v;
  
    assert (lit->val == TRUE);
  
    v = LIT2VAR (lit);
    litlevel = v->level;
  
    if (!litlevel)
      return 1;
  
  #ifndef NFL
    if (ps->simplifying)
      return 0;
  #endif
  
    return litlevel < ps->LEVEL;
  }
  #endif
  
  inline static void
  propl (PS * ps, Lit * this)
  {
    Lit **l, *other, *prev, *new_lit, **eol;
    Cls *next, **htp_ptr, **new_htp_ptr;
    Cls *c;
  #ifdef STATS
    unsigned size;
  #endif
  
    htp_ptr = LIT2HTPS (this);
    assert (this->val == FALSE);
  
    /* Traverse all non binary clauses with 'this'.  Head/Tail pointers are
     * updated as well.
     */
    for (c = *htp_ptr; c; c = next)
      {
        ps->visits++;
  #ifdef STATS
        size = c->size;
        assert (size >= 3);
        ps->traversals++;	/* other is dereferenced at least */
  
        if (size == 3)
  	ps->tvisits++;
        else if (size >= 4)
  	{
  	  ps->lvisits++;
  	  ps->ltraversals++;
  	}
  #endif
  #ifdef TRACE
        assert (!c->collected);
  #endif
        assert (c->size > 0);
  
        other = c->lits[0];
        if (other != this)
  	{
  	  assert (c->size != 1);
  	  c->lits[0] = this;
  	  c->lits[1] = other;
  	  next = c->next[1];
  	  c->next[1] = c->next[0];
  	  c->next[0] = next;
  	}
        else if (c->size == 1)	/* With assumptions we need to
  	                         * traverse unit clauses as well.
  			         */
  	{
  	  assert (!ps->conflict);
  	  ps->conflict = c;
  	  break;
  	}
        else
  	{
  	  assert (other == this && c->size > 1);
  	  other = c->lits[1];
  	  next = c->next[0];
  	}
        assert (other == c->lits[1]);
        assert (this == c->lits[0]);
        assert (next == c->next[0]);
        assert (!c->collect);
  
        if (other->val == TRUE)
  	{
  #ifdef STATS
  	  ps->othertrue++;
  	  ps->othertruel++;
  #endif
  #ifndef NDSC
  	  if (should_disconnect_head_tail (ps, other))
  	    {
  	      new_htp_ptr = LIT2DHTPS (other);
  	      c->next[0] = *new_htp_ptr;
  	      *new_htp_ptr = c;
  #ifdef STATS
  	      ps->othertruelu++;
  #endif
  	      *htp_ptr = next;
  	      continue;
  	    }
  #endif
  	  htp_ptr = c->next;
  	  continue;
  	}
  
        l = c->lits + 1;
        eol = (Lit**) c->lits + c->size;
        prev = this;
  
        while (++l != eol)
  	{
  #ifdef STATS
  	  if (size >= 3)
  	    {
  	      ps->traversals++;
  	      if (size > 3)
  		ps->ltraversals++;
  	    }
  #endif
  	  new_lit = *l;
  	  *l = prev;
  	  prev = new_lit;
  	  if (new_lit->val != FALSE) break;
  	}
  
        if (l == eol)
  	{
  	  while (l > c->lits + 2) 
  	    {
  	      new_lit = *--l;
  	      *l = prev;
  	      prev = new_lit;
  	    }
  	  assert (c->lits[0] == this);
  
  	  assert (other == c->lits[1]);
  	  if (other->val == FALSE)	/* found conflict */
  	    {
  	      assert (!ps->conflict);
  	      ps->conflict = c;
  	      return;
  	    }
  
  	  assign_forced (ps, other, c);		/* unit clause */
  	  htp_ptr = c->next;
  	}
        else
  	{
  	  assert (new_lit->val == TRUE || new_lit->val == UNDEF);
  	  c->lits[0] = new_lit;
  	  // *l = this;
  	  new_htp_ptr = LIT2HTPS (new_lit);
  	  c->next[0] = *new_htp_ptr;
  	  *new_htp_ptr = c;
  	  *htp_ptr = next;
  	}
      }
  }
  
  #ifndef NADC
  
  static unsigned primes[] = { 996293, 330643, 753947, 500873 };
  
  #define PRIMES ((sizeof primes)/sizeof *primes)
  
  static unsigned
  hash_ado (PS * ps, Lit ** ado, unsigned salt)
  {
    unsigned i, res, tmp;
    Lit ** p, * lit;
  
    assert (salt < PRIMES);
  
    i = salt;
    res = 0;
  
    for (p = ado; (lit = *p); p++)
      {
        assert (lit->val);
  
        tmp = res >> 31;
        res <<= 1;
  
        if (lit->val > 0)
  	res |= 1;
  
        assert (i < PRIMES);
        res *= primes[i++];
        if (i == PRIMES)
  	i = 0;
  
        res += tmp;
      }
  
    return res & (ps->szadotab - 1);
  }
  
  static unsigned
  cmp_ado (Lit ** a, Lit ** b)
  {
    Lit ** p, ** q, * l, * k;
    int res;
  
    for (p = a, q = b; (l = *p); p++, q++)
      {
        k = *q;
        assert (k);
        if ((res = (l->val - k->val)))
  	return res;
      }
  
    assert (!*q);
  
    return 0;
  }
  
  static Lit ***
  find_ado (PS * ps, Lit ** ado)
  {
    Lit *** res, ** other;
    unsigned pos, delta;
  
    pos = hash_ado (ps, ado, 0);
    assert (pos < ps->szadotab);
    res = ps->adotab + pos;
  
    other = *res;
    if (!other || !cmp_ado (other, ado))
      return res;
  
    delta = hash_ado (ps, ado, 1);
    if (!(delta & 1))
      delta++;
  
    assert (delta & 1);
    assert (delta < ps->szadotab);
  
    for (;;)
      {
        pos += delta;
        if (pos >= ps->szadotab)
  	pos -= ps->szadotab;
  
        assert (pos < ps->szadotab);
        res = ps->adotab + pos;
        other = *res;
        if (!other || !cmp_ado (other, ado))
  	return res;
      }
  }
  
  static void
  enlarge_adotab (PS * ps)
  {
    /* TODO make this generic */
  
    ABORTIF (ps->szadotab, 
             "internal: all different objects table needs larger initial size");
    assert (!ps->nadotab);
    ps->szadotab = 10000;
    NEWN (ps->adotab, ps->szadotab);
    CLRN (ps->adotab, ps->szadotab);
  }
  
  static int
  propado (PS * ps, Var * v)
  {
    Lit ** p, ** q, *** adotabpos, **ado, * lit;
    Var * u;
  
    if (ps->LEVEL && ps->adodisabled)
      return 1;
  
    assert (!ps->conflict);
    assert (!ps->adoconflict);
    assert (VAR2LIT (v)->val != UNDEF);
    assert (!v->adotabpos);
  
    if (!v->ado)
      return 1;
  
    assert (v->inado);
  
    for (p = v->ado; (lit = *p); p++)
      if (lit->val == UNDEF)
        {
  	u = LIT2VAR (lit);
  	assert (!u->ado);
  	u->ado = v->ado;
  	v->ado = 0;
  
  	return 1;
        }
  
    if (4 * ps->nadotab >= 3 * ps->szadotab)	/* at least 75% filled */
      enlarge_adotab (ps);
  
    adotabpos = find_ado (ps, v->ado);
    ado = *adotabpos;
  
    if (!ado)
      {
        ps->nadotab++;
        v->adotabpos = adotabpos;
        *adotabpos = v->ado;
        return 1;
      }
  
    assert (ado != v->ado);
  
    ps->adoconflict = new_clause (ps, 2 * llength (ado), 1);
    q = ps->adoconflict->lits;
  
    for (p = ado; (lit = *p); p++)
      *q++ = lit->val == FALSE ? lit : NOTLIT (lit);
  
    for (p = v->ado; (lit = *p); p++)
      *q++ = lit->val == FALSE ? lit : NOTLIT (lit);
  
    assert (q == ENDOFCLS (ps->adoconflict));
    ps->conflict = ps->adoconflict;
    ps->adoconflicts++;
    return 0;
  }
  
  #endif
  
  static void
  bcp (PS * ps)
  {
    int props = 0;
    assert (!ps->conflict);
  
    if (ps->mtcls)
      return;
  
    for (;;)
      {
        if (ps->ttail2 < ps->thead)	/* prioritize implications */
  	{
  	  props++;
  	  prop2 (ps, NOTLIT (*ps->ttail2++));
  	}
        else if (ps->ttail < ps->thead)	/* unit clauses or clauses with length > 2 */
  	{
  	  if (ps->conflict) break;
  	  propl (ps, NOTLIT (*ps->ttail++));
  	  if (ps->conflict) break;
  	}
  #ifndef NADC
        else if (ps->ttailado < ps->thead)
  	{
  	  if (ps->conflict) break;
  	  propado (ps, LIT2VAR (*ps->ttailado++));
  	  if (ps->conflict) break;
  	}
  #endif
        else
  	break;		/* all assignments propagated, so break */
      }
  
    ps->propagations += props;
  }
  
  static unsigned
  drive (PS * ps)
  {
    unsigned res, vlevel;
    Lit **p;
    Var *v;
  
    res = 0;
    for (p = ps->added; p < ps->ahead; p++)
      {
        v = LIT2VAR (*p);
        vlevel = v->level;
        assert (vlevel <= ps->LEVEL);
        if (vlevel < ps->LEVEL && vlevel > res)
  	res = vlevel;
      }
  
    return res;
  }
  
  #ifdef VISCORES
  
  static void
  viscores (PS * ps)
  {
    Rnk *p, *eor = ps->rnks + ps->max_var;
    char name[100], cmd[200];
    FILE * data;
    Flt s;
    int i;
  
    for (p = ps->rnks + 1; p <= ps->eor; p++)
      {
        s = p->score;
        if (s == INFFLT)
  	continue;
        s = mulflt (s, ps->nvinc);
        assert (flt2double (s) <= 1.0);
      }
  
    sprintf (name, "/tmp/picosat-viscores/data/%08u", ps->conflicts);
    sprintf (cmd, "sort -n|nl>%s", name);
  
    data = popen (cmd, "w");
    for (p = ps->rnks + 1; p <= ps->eor; p++)
      {
        s = p->score;
        if (s == INFFLT)
  	continue;
        s = mulflt (s, ps->nvinc);
        fprintf (data, "%lf %d\n", 100.0 * flt2double (s), (int)(p - ps->rnks));
      }
    fflush (data);
    pclose (data);
  
    for (i = 0; i < 8; i++)
      {
        sprintf (cmd, "awk '$3%%8==%d' %s>%s.%d", i, name, name, i);
        system (cmd);
      }
  
    fprintf (ps->fviscores, "set title \"%u\"\n", ps->conflicts);
    fprintf (ps->fviscores, "plot [0:%u] 0, 100 * (1 - 1/1.1), 100", ps->max_var);
  
    for (i = 0; i < 8; i++)
      fprintf (ps->fviscores, 
               ", \"%s.%d\" using 1:2:3 with labels tc lt %d", 
  	     name, i, i + 1);
  
    fputc ('\n', ps->fviscores);
    fflush (ps->fviscores);
  #ifndef WRITEGIF
    usleep (50000);		/* refresh rate of 20 Hz */
  #endif
  }
  
  #endif
  
  static void
  crescore (PS * ps)
  {
    Cls **p, *c;
    Act *a;
    Flt factor;
    int l = log2flt (ps->cinc);
    assert (l > 0);
    factor = base2flt (1, -l);
  
    for (p = ps->lclauses; p != ps->lhead; p++)
      {
        c = *p;
  
        if (!c)
  	continue;
  
  #ifdef TRACE
        if (c->collected)
  	continue;
  #endif
        assert (c->learned);
  
        if (c->size <= 2)
  	continue;
  
        a = CLS2ACT (c);
        *a = mulflt (*a, factor);
      }
  
    ps->cinc = mulflt (ps->cinc, factor);
  }
  
  static void
  inc_vinc (PS * ps)
  {
  #ifdef VISCORES
    ps->nvinc = mulflt (ps->nvinc, ps->fvinc);
  #endif
    ps->vinc = mulflt (ps->vinc, ps->ifvinc);
  }
  
  inline static void
  inc_max_var (PS * ps)
  {
    Lit *lit;
    Rnk *r;
    Var *v;
  
    assert (ps->max_var < ps->size_vars);
  
    if (ps->max_var + 1 == ps->size_vars)
      enlarge (ps, ps->size_vars + 2*(ps->size_vars + 3) / 4); /* +25% */
  
    ps->max_var++;			/* new index of variable */
    assert (ps->max_var);			/* no unsigned overflow */
  
    assert (ps->max_var < ps->size_vars);
  
    lit = ps->lits + 2 * ps->max_var;
    lit[0].val = lit[1].val = UNDEF;
  
    memset (ps->htps + 2 * ps->max_var, 0, 2 * sizeof *ps->htps);
  #ifndef NDSC
    memset (ps->dhtps + 2 * ps->max_var, 0, 2 * sizeof *ps->dhtps);
  #endif
    memset (ps->impls + 2 * ps->max_var, 0, 2 * sizeof *ps->impls);
    memset (ps->jwh + 2 * ps->max_var, 0, 2 * sizeof *ps->jwh);
  
    v = ps->vars + ps->max_var;		/* initialize variable components */
    CLR (v);
  
    r = ps->rnks + ps->max_var;		/* initialize rank */
    CLR (r);
  
    hpush (ps, r);
  }
  
  static void
  force (PS * ps, Cls * c)
  {
    Lit ** p, ** eol, * lit, * forced;
    Cls * reason;
  
    forced = 0;
    reason = c;
  
    eol = end_of_lits (c);
    for (p = c->lits; p < eol; p++)
      {
        lit = *p;
        if (lit->val == UNDEF)
  	{
  	  assert (!forced);
  	  forced = lit;
  #ifdef NO_BINARY_CLAUSES
  	  if (c == &ps->impl)
  	    reason = LIT2REASON (NOTLIT (p[p == c->lits ? 1 : -1]));
  #endif
  	}
        else
  	assert (lit->val == FALSE);
      }
  
  #ifdef NO_BINARY_CLAUSES
    if (c == &ps->impl)
      resetimpl (ps);
  #endif
    if (!forced)
      return;
  
    assign_forced (ps, forced, reason);
  }
  
  static void
  inc_lreduce (PS * ps)
  {
  #ifdef STATS
    ps->inclreduces++;
  #endif
    ps->lreduce *= FREDUCE;
    ps->lreduce /= 100;
    report (ps, 1, '+');
  }
  
  static void
  backtrack (PS * ps)
  {
    unsigned new_level;
    Cls * c;
  
    ps->conflicts++;
    LOG ( fprintf (ps->out, "%sconflict ", ps->prefix); dumpclsnl (ps, ps->conflict));
  
    analyze (ps);
    new_level = drive (ps);
    // TODO: why not? assert (new_level != 1  || (ps->ahead - ps->added) == 2);
    c = add_simplified_clause (ps, 1);
    undo (ps, new_level);
    force (ps, c);
  
    if (
  #ifndef NFL
        !ps->simplifying && 
  #endif
        !--ps->lreduceadjustcnt)
      {
        /* With FREDUCE==110 and FREDADJ=121 we stir 'lreduce' to be
         * proportional to 'sqrt(conflicts)'.  In earlier version we actually
         * used  'FREDADJ=150', which results in 'lreduce' to approximate
         * 'conflicts^(log(1.1)/log(1.5))' which is close to the fourth root
         * of 'conflicts', since log(1.1)/log(1.5)=0.235 (as observed by
         * Donald Knuth). The square root is the same we get by a Glucose
         * style increase, which simply adds a constant at every reduction.
         * This would be way simpler to implement but for now we keep the more
         * complicated code using the adjust increments and counters.
         */
        ps->lreduceadjustinc *= FREDADJ; ps->lreduceadjustinc /= 100; ps->lreduceadjustcnt
        = ps->lreduceadjustinc;
        inc_lreduce (ps);
      }
  
    if (ps->verbosity >= 4 && !(ps->conflicts % 1000))
      report (ps, 4, 'C');
  }
  
  static void
  inc_cinc (PS * ps)
  {
    ps->cinc = mulflt (ps->cinc, ps->fcinc);
    if (ps->lcinc < ps->cinc)
      crescore (ps);
  }
  
  static void
  incincs (PS * ps)
  {
    inc_vinc (ps);
    inc_cinc (ps);
  #ifdef VISCORES
    viscores (ps);
  #endif
  }
  
  static void
  disconnect_clause (PS * ps, Cls * c)
  {
    assert (c->connected);
  
    if (c->size > 2)
      {
        if (c->learned)
  	{
  	  assert (ps->nlclauses > 0);
  	  ps->nlclauses--;
  
  	  assert (ps->llits >= c->size);
  	  ps->llits -= c->size;
  	}
        else
  	{
  	  assert (ps->noclauses > 0);
  	  ps->noclauses--;
  
  	  assert (ps->olits >= c->size);
  	  ps->olits -= c->size;
  	}
      }
  
  #ifndef NDEBUG
    c->connected = 0;
  #endif
  }
  
  static int
  clause_is_toplevel_satisfied (PS * ps, Cls * c)
  {
    Lit *lit, **p, **eol = end_of_lits (c);
    Var *v;
  
    for (p = c->lits; p < eol; p++)
      {
        lit = *p;
        if (lit->val == TRUE)
  	{
  	  v = LIT2VAR (lit);
  	  if (!v->level)
  	    return 1;
  	}
      }
  
    return 0;
  }
  
  static int
  collect_clause (PS * ps, Cls * c)
  {
    assert (c->collect);
    c->collect = 0;
  
  #ifdef TRACE
    assert (!c->collected);
    c->collected = 1;
  #endif
    disconnect_clause (ps, c);
  
  #ifdef TRACE
    if (ps->trace && (!c->learned || c->used))
      return 0;
  #endif
    delete_clause (ps, c);
  
    return 1;
  }
  
  static size_t
  collect_clauses (PS * ps)
  {
    Cls *c, **p, **q, * next;
    Lit * lit, * eol;
    size_t res;
    int i;
  
    res = ps->current_bytes;
  
    eol = ps->lits + 2 * ps->max_var + 1;
    for (lit = ps->lits + 2; lit <= eol; lit++)
      {
        for (i = 0; i <= 1; i++)
  	{
  	  if (i)
  	    {
  #ifdef NO_BINARY_CLAUSES
  	      Ltk * lstk = LIT2IMPLS (lit);
  	      Lit ** r, ** s;
  	      r = lstk->start;
  	      if (lit->val != TRUE || LIT2VAR (lit)->level)
  		for (s = r; s < lstk->start + lstk->count; s++)
  		  {
  		    Lit * other = *s;
  		    Var *v = LIT2VAR (other);
  		    if (v->level ||
  		        other->val != TRUE)
  		      *r++ = other;
  		  }
  	      lstk->count = r - lstk->start;
  	      continue;
  #else
  	      p = LIT2IMPLS (lit);
  #endif
  	    }
  	  else
  	    p = LIT2HTPS (lit);
  
  	  for (c = *p; c; c = next)
  	    {
  	      q = c->next;
  	      if (c->lits[0] != lit)
  		q++;
  
  	      next = *q;
  	      if (c->collect)
  		*p = next;
  	      else
  		p = q;
  	    }
  	}
      }
  
  #ifndef NDSC
    for (lit = ps->lits + 2; lit <= eol; lit++)
      {
        p = LIT2DHTPS (lit); 
        while ((c = *p))
  	{
  	  Lit * other = c->lits[0];
  	  if (other == lit)
  	    {
  	      q = c->next + 1;
  	    }
  	  else
  	    {
  	      assert (c->lits[1] == lit);
  	      q = c->next;
  	    }
  
  	  if (c->collect)
  	    *p = *q;
  	  else
  	    p = q;
  	}
      }
  #endif
  
    for (p = SOC; p != EOC; p = NXC (p))
      {
        c = *p;
  
        if (!c)
  	continue;
  
        if (!c->collect)
  	continue;
  
        if (collect_clause (ps, c))
  	*p = 0;
      }
  
  #ifdef TRACE
    if (!ps->trace)
  #endif
      {
        q = ps->oclauses;
        for (p = q; p < ps->ohead; p++)
  	if ((c = *p))
  	  *q++ = c;
        ps->ohead = q;
  
        q = ps->lclauses;
        for (p = q; p < ps->lhead; p++)
  	if ((c = *p))
  	  *q++ = c;
        ps->lhead = q;
      }
  
    assert (ps->current_bytes <= res);
    res -= ps->current_bytes;
    ps->recycled += res;
  
    LOG ( fprintf (ps->out, "%scollected %ld bytes\n", ps->prefix, (long)res));
  
    return res;
  }
  
  static int
  need_to_reduce (PS * ps)
  {
    return ps->nlclauses >= reduce_limit_on_lclauses (ps);
  }
  
  #ifdef NLUBY
  
  static void
  inc_drestart (PS * ps)
  {
    ps->drestart *= FRESTART;
    ps->drestart /= 100;
  
    if (ps->drestart >= MAXRESTART)
      ps->drestart = MAXRESTART;
  }
  
  static void
  inc_ddrestart (PS * ps)
  {
    ps->ddrestart *= FRESTART;
    ps->ddrestart /= 100;
  
    if (ps->ddrestart >= MAXRESTART)
      ps->ddrestart = MAXRESTART;
  }
  
  #else
  
  static unsigned
  luby (unsigned i)
  {
    unsigned k;
    for (k = 1; k < 32; k++)
      if (i == (1u << k) - 1)
        return 1u << (k - 1);
  
    for (k = 1;; k++)
      if ((1u << (k - 1)) <= i && i < (1u << k) - 1)
        return luby (i - (1u << (k-1)) + 1);
  }
  
  #endif
  
  #ifndef NLUBY
  static void
  inc_lrestart (PS * ps, int skip)
  {
    unsigned delta;
  
    delta = 100 * luby (++ps->lubycnt);
    ps->lrestart = ps->conflicts + delta;
  
    if (ps->waslubymaxdelta)
      report (ps, 1, skip ? 'N' : 'R');
    else
      report (ps, 2, skip ? 'n' : 'r');
  
    if (delta > ps->lubymaxdelta)
      {
        ps->lubymaxdelta = delta;
        ps->waslubymaxdelta = 1;
      }
    else
      ps->waslubymaxdelta = 0;
  }
  #endif
  
  static void
  init_restart (PS * ps)
  {
  #ifdef NLUBY
    /* TODO: why is it better in incremental usage to have smaller initial
     * outer restart interval?
     */
    ps->ddrestart = ps->calls > 1 ? MINRESTART : 1000;
    ps->drestart = MINRESTART;
    ps->lrestart = ps->conflicts + ps->drestart;
  #else
    ps->lubycnt = 0;
    ps->lubymaxdelta = 0;
    ps->waslubymaxdelta = 0;
    inc_lrestart (ps, 0);
  #endif
  }
  
  static void
  restart (PS * ps)
  {
    int skip; 
  #ifdef NLUBY
    char kind;
    int outer;
   
    inc_drestart (ps);
    outer = (ps->drestart >= ps->ddrestart);
  
    if (outer)
      skip = very_high_agility (ps);
    else
      skip = high_agility (ps);
  #else
    skip = medium_agility (ps);
  #endif
  
  #ifdef STATS
    if (skip)
      ps->skippedrestarts++;
  #endif
  
    assert (ps->conflicts >= ps->lrestart);
  
    if (!skip)
      {
        ps->restarts++;
        assert (ps->LEVEL > 1);
        LOG ( fprintf (ps->out, "%srestart %u\n", ps->prefix, ps->restarts));
        undo (ps, 0);
      }
  
  #ifdef NLUBY
    if (outer)
      {
        kind = skip ? 'N' : 'R';
        inc_ddrestart (ps);
        ps->drestart = MINRESTART;
      }
    else  if (skip)
      {
        kind = 'n';
      }
    else
      {
        kind = 'r';
      }
  
    assert (ps->drestart <= MAXRESTART);
    ps->lrestart = ps->conflicts + ps->drestart;
    assert (ps->lrestart > ps->conflicts);
  
    report (outer ? 1 : 2, kind);
  #else
    inc_lrestart (ps, skip);
  #endif
  }
  
  inline static void
  assign_decision (PS * ps, Lit * lit)
  {
    assert (!ps->conflict);
  
    ps->LEVEL++;
  
    LOG ( fprintf (ps->out, "%snew level %u\n", ps->prefix, ps->LEVEL));
    LOG ( fprintf (ps->out,
  		 "%sassign %d at level %d <= DECISION\n",
  		 ps->prefix, LIT2INT (lit), ps->LEVEL));
  
    assign (ps, lit, 0);
  }
  
  #ifndef NFL
  
  static int
  lit_has_binary_clauses (PS * ps, Lit * lit)
  {
  #ifdef NO_BINARY_CLAUSES
    Ltk* lstk = LIT2IMPLS (lit);
    return lstk->count != 0;
  #else
    return *LIT2IMPLS (lit) != 0;
  #endif
  }
  
  static void
  flbcp (PS * ps)
  {
  #ifdef STATS
    unsigned long long propagaions_before_bcp = ps->propagations;
  #endif
    bcp (ps);
  #ifdef STATS
    ps->flprops += ps->propagations - propagaions_before_bcp;
  #endif
  }
  
  inline static int
  cmp_inverse_rnk (PS * ps, Rnk * a, Rnk * b)
  {
    (void) ps;
    return -cmp_rnk (a, b);
  }
  
  inline static Flt
  rnk2jwh (PS * ps, Rnk * r)
  {
    Flt res, sum, pjwh, njwh;
    Lit * plit, * nlit;
  
    plit = RNK2LIT (r);
    nlit = plit + 1;
    
    pjwh = *LIT2JWH (plit);
    njwh = *LIT2JWH (nlit);
  
    res = mulflt (pjwh, njwh);
  
    sum = addflt (pjwh, njwh);
    sum = mulflt (sum, base2flt (1, -10));
    res = addflt (res, sum);
  
    return res;
  }
  
  static int
  cmp_inverse_jwh_rnk (PS * ps, Rnk * r, Rnk * s)
  {
    Flt a = rnk2jwh (ps, r);
    Flt b = rnk2jwh (ps, s);
    int res = cmpflt (a, b);
  
    if (res)
      return -res;
  
    return cmp_inverse_rnk (ps, r, s);
  }
  
  static void
  faillits (PS * ps)
  {
    unsigned i, j, old_trail_count, common, saved_count;
    unsigned new_saved_size, oldladded = ps->ladded;
    unsigned long long limit, delta;
    Lit * lit, * other, * pivot;
    Rnk * r, ** p, ** q;
    int new_trail_count;
    double started;
  
    if (ps->plain)
      return;
  
    if (ps->heap + 1 >= ps->hhead)
      return;
  
    if (ps->propagations < ps->fllimit)
      return;
  
    sflush (ps);
    started = ps->seconds;
  
    ps->flcalls++;
  #ifdef STATSA
    ps->flrounds++;
  #endif
    delta = ps->propagations/10;
    if (delta >= 100*1000*1000) delta = 100*1000*1000;
    else if (delta <= 100*1000) delta = 100*1000;
  
    limit = ps->propagations + delta;
    ps->fllimit = ps->propagations;
  
    assert (!ps->LEVEL);
    assert (ps->simplifying);
  
    if (ps->flcalls <= 1)
      SORT (Rnk *, cmp_inverse_jwh_rnk, ps->heap + 1, ps->hhead - (ps->heap + 1));
    else
      SORT (Rnk *, cmp_inverse_rnk, ps->heap + 1, ps->hhead - (ps->heap + 1));
  
    i = 1;		/* NOTE: heap starts at position '1' */
  
    while (ps->propagations < limit)
      {
        if (ps->heap + i == ps->hhead)
  	{
  	  if (ps->ladded == oldladded)
  	    break;
  
  	  i = 1;
  #ifdef STATS
  	  ps->flrounds++;
  #endif
  	  oldladded = ps->ladded;
  	}
  
        assert (ps->heap + i < ps->hhead);
  
        r = ps->heap[i++];
        lit = RNK2LIT (r);
  
        if (lit->val)
  	continue;
  
        if (!lit_has_binary_clauses (ps, NOTLIT (lit)))
  	{
  #ifdef STATS
  	  ps->flskipped++;
  #endif
  	  continue;
  	}
  
  #ifdef STATS
        ps->fltried++;
  #endif
        LOG ( fprintf (ps->out, "%strying %d as failed literal\n",
  	    ps->prefix, LIT2INT (lit)));
  
        assign_decision (ps, lit);
        old_trail_count = ps->thead - ps->trail;
        flbcp (ps);
  
        if (ps->conflict)
  	{
  EXPLICITLY_FAILED_LITERAL:
  	  LOG ( fprintf (ps->out, "%sfound explicitly failed literal %d\n",
  		ps->prefix, LIT2INT (lit)));
  
  	  ps->failedlits++;
  	  ps->efailedlits++;
  
  	  backtrack (ps);
  	  flbcp (ps);
  
  	  if (!ps->conflict)
  	    continue;
  
  CONTRADICTION:
  	  assert (!ps->LEVEL);
  	  backtrack (ps);
  	  assert (ps->mtcls);
  
  	  goto RETURN;
  	}
  
        if (ps->propagations >= limit)
  	{
  	  undo (ps, 0);
  	  break;
  	}
  
        lit = NOTLIT (lit);
  
        if (!lit_has_binary_clauses (ps, NOTLIT (lit)))
  	{
  #ifdef STATS
  	  ps->flskipped++;
  #endif
  	  undo (ps, 0);
  	  continue;
  	}
  
  #ifdef STATS
        ps->fltried++;
  #endif
        LOG ( fprintf (ps->out, "%strying %d as failed literals\n",
  	    ps->prefix, LIT2INT (lit)));
  
        new_trail_count = ps->thead - ps->trail;
        saved_count = new_trail_count - old_trail_count;
  
        if (saved_count > ps->saved_size)
  	{
  	  new_saved_size = ps->saved_size ? 2 * ps->saved_size : 1;
  	  while (saved_count > new_saved_size)
  	    new_saved_size *= 2;
  
  	  RESIZEN (ps->saved, ps->saved_size, new_saved_size);
  	  ps->saved_size = new_saved_size;
  	}
  
        for (j = 0; j < saved_count; j++)
  	ps->saved[j] = ps->trail[old_trail_count + j];
  
        undo (ps, 0);
  
        assign_decision (ps, lit);
        flbcp (ps);
  
        if (ps->conflict)
  	goto EXPLICITLY_FAILED_LITERAL;
  
        pivot = (ps->thead - ps->trail <= new_trail_count) ? lit : NOTLIT (lit);
  
        common = 0;
        for (j = 0; j < saved_count; j++)
  	if ((other = ps->saved[j])->val == TRUE)
  	  ps->saved[common++] = other;
  
        undo (ps, 0);
  
        LOG (if (common)
  	     fprintf (ps->out, 
  		      "%sfound %d literals implied by %d and %d\n",
  		      ps->prefix, common, 
  		      LIT2INT (NOTLIT (lit)), LIT2INT (lit)));
  
  #if 1 // set to zero to disable 'lifting'
        for (j = 0; 
  	   j < common 
  	  /* TODO: For some Velev benchmarks, extracting the common implicit
  	   * failed literals took quite some time.  This needs to be fixed by
  	   * a dedicated analyzer.  Up to then we bound the number of
  	   * propagations in this loop as well.
  	   */
  	   && ps->propagations < limit + delta
  	   ; j++)
  	{
  	  other = ps->saved[j];
  
  	  if (other->val == TRUE)
  	    continue;
  
  	  assert (!other->val);
  
  	  LOG ( fprintf (ps->out, 
  			"%sforcing %d as forced implicitly failed literal\n",
  			ps->prefix, LIT2INT (other)));
  
  	  assert (pivot != NOTLIT (other));
  	  assert (pivot != other);
  
  	  assign_decision (ps, NOTLIT (other));
  	  flbcp (ps);
  
  	  assert (ps->LEVEL == 1);
  
  	  if (ps->conflict)
  	    {
  	      backtrack (ps);
  	      assert (!ps->LEVEL);
  	    }
  	  else
  	    {
  	      assign_decision (ps, pivot);
  	      flbcp (ps);
  
  	      backtrack (ps);
  
  	      if (ps->LEVEL)
  		{
  		  assert (ps->LEVEL == 1);
  
  		  flbcp (ps);
  
  		  if (ps->conflict)
  		    {
  		      backtrack (ps);
  		      assert (!ps->LEVEL);
  		    }
  		  else
  		    {
  		      assign_decision (ps, NOTLIT (pivot));
  		      flbcp (ps);
  		      backtrack (ps);
  
  		      if (ps->LEVEL)
  			{
  			  assert (ps->LEVEL == 1);
  			  flbcp (ps);
  
  			  if (!ps->conflict)
  			    {
  #ifdef STATS
  			      ps->floopsed++;
  #endif
  			      undo (ps, 0);
  			      continue;
  			    }
  
  			  backtrack (ps);
  			}
  
  		      assert (!ps->LEVEL);
  		    }
  
  		  assert (!ps->LEVEL);
  		}
  	    }
  	  assert (!ps->LEVEL);
  	  flbcp (ps);
  
  	  ps->failedlits++;
  	  ps->ifailedlits++;
  
  	  if (ps->conflict)
  	    goto CONTRADICTION;
  	}
  #endif
      }
  
    ps->fllimit += 9 * (ps->propagations - ps->fllimit);	/* 10% for failed literals */
  
  RETURN:
  
    /* First flush top level assigned literals.  Those are prohibited from
     * being pushed up the heap during 'faillits' since 'simplifying' is set.
     */
    assert (ps->heap < ps->hhead);
    for (p = q = ps->heap + 1; p < ps->hhead; p++)
      {
        r = *p;
        lit = RNK2LIT (r);
        if (lit->val)
         	r->pos = 0;
        else
  	*q++ = r;
      }
  
    /* Then resort with respect to EVSIDS score and fix positions.
     */
    SORT (Rnk *, cmp_inverse_rnk, ps->heap + 1, ps->hhead - (ps->heap + 1));
    for (p = ps->heap + 1; p < ps->hhead; p++)
      (*p)->pos = p - ps->heap;
  
    sflush (ps);
    ps->flseconds += ps->seconds - started;
  }
  
  #endif
  
  static void
  simplify (PS * ps, int forced)
  {
    Lit * lit, * notlit, ** t;
    unsigned collect, delta;
  #ifdef STATS
    size_t bytes_collected;
  #endif
    int * q, ilit;
    Cls **p, *c;
    Var * v;
  
  #ifndef NDEDBUG
    (void) forced;
  #endif
  
    assert (!ps->mtcls);
    assert (!satisfied (ps));
    assert (forced || ps->lsimplify <= ps->propagations);
    assert (forced || ps->fsimplify <= ps->fixed);
  
    if (ps->LEVEL)
      undo (ps, 0);
  #ifndef NFL
    ps->simplifying = 1;
    faillits (ps);
    ps->simplifying = 0;
  
    if (ps->mtcls)
      return;
  #endif
  
    if (ps->cils != ps->cilshead)
      {
        assert (ps->ttail == ps->thead);
        assert (ps->ttail2 == ps->thead);
        ps->ttail = ps->trail;
        for (t = ps->trail; t < ps->thead; t++)
  	{
  	  lit = *t;
  	  v = LIT2VAR (lit);
  	  if (v->internal)
  	    {
  	      assert (LIT2INT (lit) < 0);
  	      assert (lit->val == TRUE);
  	      unassign (ps, lit);
  	    }
  	  else
  	    *ps->ttail++ = lit;
  	}
        ps->ttail2 = ps->thead = ps->ttail;
  
        for (q = ps->cils; q != ps->cilshead; q++)
  	{
  	  ilit = *q;
  	  assert (0 < ilit && ilit <= (int) ps->max_var);
  	  v = ps->vars + ilit;
  	  assert (v->internal);
  	  v->level = 0;
  	  v->reason = 0;
  	  lit = int2lit (ps, -ilit);
  	  assert (lit->val == UNDEF);
  	  lit->val = TRUE;
  	  notlit = NOTLIT (lit);
  	  assert (notlit->val == UNDEF);
  	  notlit->val = FALSE;
  	}
      }
  
    collect = 0;
    for (p = SOC; p != EOC; p = NXC (p))
      {
        c = *p;
        if (!c)
  	continue;
  
  #ifdef TRACE
        if (c->collected)
  	continue;
  #endif
  
        if (c->locked)
  	continue;
        
        assert (!c->collect);
        if (clause_is_toplevel_satisfied (ps, c))
  	{
  	  mark_clause_to_be_collected (c);
  	  collect++;
  	}
      }
  
    LOG ( fprintf (ps->out, "%scollecting %d clauses\n", ps->prefix, collect));
  #ifdef STATS
    bytes_collected = 
  #endif
    collect_clauses (ps);
  #ifdef STATS
    ps->srecycled += bytes_collected;
  #endif
  
    if (ps->cils != ps->cilshead)
      {
        for (q = ps->cils; q != ps->cilshead; q++)
  	{
  	  ilit = *q;
  	  assert (0 < ilit && ilit <= (int) ps->max_var);
  	  assert (ps->vars[ilit].internal);
  	  if (ps->rilshead == ps->eorils)
  	    ENLARGE (ps->rils, ps->rilshead, ps->eorils);
  	  *ps->rilshead++ = ilit;
  	  lit = int2lit (ps, -ilit);
  	  assert (lit->val == TRUE);
  	  lit->val = UNDEF;
  	  notlit = NOTLIT (lit);
  	  assert (notlit->val == FALSE);
  	  notlit->val = UNDEF;
  	}
        ps->cilshead = ps->cils;
      }
  
    delta = 10 * (ps->olits + ps->llits) + 100000;
    if (delta > 2000000)
      delta = 2000000;
    ps->lsimplify = ps->propagations + delta;
    ps->fsimplify = ps->fixed;
    ps->simps++;
  
    report (ps, 1, 's');
  }
  
  static void
  iteration (PS * ps)
  {
    assert (!ps->LEVEL);
    assert (bcp_queue_is_empty (ps));
    assert (ps->isimplify < ps->fixed);
  
    ps->iterations++;
    report (ps, 2, 'i');
  #ifdef NLUBY
    ps->drestart = MINRESTART;
    ps->lrestart = ps->conflicts + ps->drestart;
  #else
    init_restart (ps);
  #endif
    ps->isimplify = ps->fixed;
  }
  
  static int
  cmp_glue_activity_size (PS * ps, Cls * c, Cls * d)
  {
    Act a, b, * p, * q;
  
    (void) ps;
  
    assert (c->learned);
    assert (d->learned);
  
    if (c->glue < d->glue)		// smaller glue preferred
      return 1;
  
    if (c->glue > d->glue)
      return -1;
  
    p = CLS2ACT (c);
    q = CLS2ACT (d);
    a = *p;
    b = *q;
  
    if (a < b)				// then higher activity
      return -1;
  
    if (b < a)
      return 1;
  
    if (c->size < d->size)		// then smaller size
      return 1;
  
    if (c->size > d->size)
      return -1;
  
    return 0;
  }
  
  static void
  reduce (PS * ps, unsigned percentage)
  {
    unsigned redcount, lcollect, collect, target;
  #ifdef STATS
    size_t bytes_collected;
  #endif
    Cls **p, *c;
  
    assert (ps->rhead == ps->resolved);
  
    ps->lastreduceconflicts = ps->conflicts;
  
    assert (percentage <= 100);
    LOG ( fprintf (ps->out, 
                  "%sreducing %u%% learned clauses\n",
  		ps->prefix, percentage));
  
    while (ps->nlclauses - ps->llocked > (unsigned)(ps->eor - ps->resolved))
      ENLARGE (ps->resolved, ps->rhead, ps->eor);
  
    collect = 0;
    lcollect = 0;
  
    for (p = ((ps->fsimplify < ps->fixed) ? SOC : ps->lclauses); p != EOC; p = NXC (p))
      {
        c = *p;
        if (!c)
  	continue;
  
  #ifdef TRACE
        if (c->collected)
  	continue;
  #endif
  
        if (c->locked)
  	continue;
  
        assert (!c->collect);
        if (ps->fsimplify < ps->fixed && clause_is_toplevel_satisfied (ps, c))
  	{
  	  mark_clause_to_be_collected (c);
  	  collect++;
  
  	  if (c->learned && c->size > 2)
  	    lcollect++;
  
  	  continue;
  	}
  
        if (!c->learned)
  	continue;
  
        if (c->size <= 2)
  	continue;
  
        assert (ps->rhead < ps->eor);
        *ps->rhead++ = c;
      }
    assert (ps->rhead <= ps->eor);
  
    ps->fsimplify = ps->fixed;
  
    redcount = ps->rhead - ps->resolved;
    SORT (Cls *, cmp_glue_activity_size, ps->resolved, redcount);
  
    assert (ps->nlclauses >= lcollect);
    target = ps->nlclauses - lcollect + 1;
  
    target = (percentage * target + 99) / 100;
  
    if (target >= redcount)
      target = redcount;
  
    ps->rhead = ps->resolved + target;
    while (ps->rhead > ps->resolved)
      {
        c = *--ps->rhead;
        mark_clause_to_be_collected (c);
  
        collect++;
        if (c->learned && c->size > 2)	/* just for consistency */
  	lcollect++;
      }
  
    if (collect)
      {
        ps->reductions++;
  #ifdef STATS
        bytes_collected = 
  #endif
        collect_clauses (ps);
  #ifdef STATS
        ps->rrecycled += bytes_collected;
  #endif
        report (ps, 2, '-');
      }
  
    if (!lcollect)
      inc_lreduce (ps);		/* avoid dead lock */
  
    assert (ps->rhead == ps->resolved);
  }
  
  static void
  init_reduce (PS * ps)
  {
    // lreduce = loadded / 2;
    ps->lreduce = 1000;
  
    if (ps->lreduce < 100)
      ps->lreduce = 100;
  
    if (ps->verbosity)
       fprintf (ps->out, 
               "%s\n%sinitial reduction limit %u clauses\n%s\n",
  	     ps->prefix, ps->prefix, ps->lreduce, ps->prefix);
  }
  
  static unsigned
  rng (PS * ps)
  {
    unsigned res = ps->srng;
    ps->srng *= 1664525u;
    ps->srng += 1013904223u;
    NOLOG ( fprintf (ps->out, "%srng () = %u\n", ps->prefix, res));
    return res;
  }
  
  static unsigned
  rrng (PS * ps, unsigned low, unsigned high)
  {
    unsigned long long tmp;
    unsigned res, elements;
    assert (low <= high);
    elements = high - low + 1;
    tmp = rng (ps);
    tmp *= elements;
    tmp >>= 32;
    tmp += low;
    res = tmp;
    NOLOG ( fprintf (ps->out, "%srrng (ps, %u, %u) = %u\n", ps->prefix, low, high, res));
    assert (low <= res);
    assert (res <= high);
    return res;
  }
  
  static Lit *
  decide_phase (PS * ps, Lit * lit)
  {
    Lit * not_lit = NOTLIT (lit);
    Var *v = LIT2VAR (lit);
  
    assert (LIT2SGN (lit) > 0);
    if (v->usedefphase)
      {
        if (v->defphase)
  	{
  	  /* assign to TRUE */
  	}
        else
  	{
  	  /* assign to FALSE */
  	  lit = not_lit;
  	}
      }
    else if (!v->assigned)
      {
  #ifdef STATS
        ps->staticphasedecisions++;
  #endif
        if (ps->defaultphase == POSPHASE)
  	{
  	  /* assign to TRUE */
  	}
        else if (ps->defaultphase == NEGPHASE)
  	{
  	  /* assign to FALSE */
  	  lit = not_lit;
  	}
        else if (ps->defaultphase == RNDPHASE)
  	{
  	  /* randomly assign default phase */
  	  if (rrng (ps, 1, 2) != 2)
  	    lit = not_lit;
  	}
        else if (*LIT2JWH(lit) <= *LIT2JWH (not_lit))
  	{
  	  /* assign to FALSE (Jeroslow-Wang says there are more short
  	   * clauses with negative occurence of this variable, so satisfy
  	   * those, to minimize BCP) 
  	   */
  	  lit = not_lit;
  	}
        else
  	{
  	  /* assign to TRUE (... but strictly more positive occurrences) */
  	}
      }
    else 
      {
        /* repeat last phase: phase saving heuristic */
  
        if (v->phase)
  	{
  	  /* assign to TRUE (last phase was TRUE as well) */
  	}
        else
  	{
  	  /* assign to FALSE (last phase was FALSE as well) */
  	  lit = not_lit;
  	}
      }
  
    return lit;
  }
  
  static unsigned
  gcd (unsigned a, unsigned b)
  {
    unsigned tmp;
  
    assert (a);
    assert (b);
  
    if (a < b)
      {
        tmp = a;
        a = b;
        b = tmp;
      }
  
    while (b)
      {
        assert (a >= b);
        tmp = b;
        b = a % b;
        a = tmp;
      }
  
    return a;
  }
  
  static Lit *
  rdecide (PS * ps)
  {
    unsigned idx, delta, spread;
    Lit * res;
  
    spread = RDECIDE;
    if (rrng (ps, 1, spread) != 2)
      return 0;
  
    assert (1 <= ps->max_var);
    idx = rrng (ps, 1, ps->max_var);
    res = int2lit (ps, idx);
  
    if (res->val != UNDEF)
      {
        delta = rrng (ps, 1, ps->max_var);
        while (gcd (delta, ps->max_var) != 1)
  	delta--;
  
        assert (1 <= delta);
        assert (delta <= ps->max_var);
  
        do {
  	idx += delta;
  	if (idx > ps->max_var)
  	  idx -= ps->max_var;
  	res = int2lit (ps, idx);
        } while (res->val != UNDEF);
      }
  
  #ifdef STATS
    ps->rdecisions++;
  #endif
    res = decide_phase (ps, res);
    LOG ( fprintf (ps->out, "%srdecide %d\n", ps->prefix, LIT2INT (res)));
  
    return res;
  }
  
  static Lit *
  sdecide (PS * ps)
  {
    Lit *res;
    Rnk *r;
  
    for (;;)
      {
        r = htop (ps);
        res = RNK2LIT (r);
        if (res->val == UNDEF) break;
        (void) hpop (ps);
        NOLOG ( fprintf (ps->out, 
                        "%shpop %u %u %u\n",
  		      ps->prefix, r - ps->rnks,
  		      FLTMANTISSA(r->score),
  		      FLTEXPONENT(r->score)));
      }
  
  #ifdef STATS
    ps->sdecisions++;
  #endif
    res = decide_phase (ps, res);
  
    LOG ( fprintf (ps->out, "%ssdecide %d\n", ps->prefix, LIT2INT (res)));
  
    return res;
  }
  
  static Lit *
  adecide (PS * ps)
  {
    Lit *lit;
    Var * v;
  
    assert (ps->als < ps->alshead);
    assert (!ps->failed_assumption);
  
    while (ps->alstail < ps->alshead)
      {
        lit = *ps->alstail++;
  
        if (lit->val == FALSE)
  	{
  	  ps->failed_assumption = lit;
  	  v = LIT2VAR (lit);
  
  	  use_var (ps, v);
  
  	  LOG ( fprintf (ps->out, "%sfirst failed assumption %d\n",
  			ps->prefix, LIT2INT (ps->failed_assumption)));
  	  fanalyze (ps);
  	  return 0;
  	}
  
        if (lit->val == TRUE)
  	{
  	  v = LIT2VAR (lit);
  	  if (v->level > ps->adecidelevel)
  	    ps->adecidelevel = v->level;
  	  continue;
  	}
  
  #ifdef STATS
        ps->assumptions++;
  #endif
        LOG ( fprintf (ps->out, "%sadecide %d\n", ps->prefix, LIT2INT (lit)));
        ps->adecidelevel = ps->LEVEL + 1;
  
        return lit;
      }
  
    return 0;
  }
  
  static void
  decide (PS * ps)
  {
    Lit * lit;
  
    assert (!satisfied (ps));
    assert (!ps->conflict);
  
    if (ps->alstail < ps->alshead && (lit = adecide (ps)))
      ;
    else if (ps->failed_assumption)
      return;
    else if (satisfied (ps))
      return;
    else if (!(lit = rdecide (ps)))
      lit = sdecide (ps);
  
    assert (lit);
    assign_decision (ps, lit);
  
    ps->levelsum += ps->LEVEL;
    ps->decisions++;
  }
  
  static int
  sat (PS * ps, int l)
  {
    int count = 0, backtracked;
  
    if (!ps->conflict)
      bcp (ps);
  
    if (ps->conflict)
      backtrack (ps);
  
    if (ps->mtcls)
      return PICOSAT_UNSATISFIABLE;
  
    if (satisfied (ps))
      goto SATISFIED;
  
    if (ps->lsimplify <= ps->propagations)
      simplify (ps, 0);
  
    if (ps->mtcls)
      return PICOSAT_UNSATISFIABLE;
  
    if (satisfied (ps))
      goto SATISFIED;
  
    init_restart (ps);
  
    if (!ps->lreduce)
      init_reduce (ps);
  
    ps->isimplify = ps->fixed;
    backtracked = 0;
  
    for (;;)
      {
        if (!ps->conflict)
  	bcp (ps);
  
        if (ps->conflict)
  	{
  	  incincs (ps);
  	  backtrack (ps);
  
  	  if (ps->mtcls)
  	    return PICOSAT_UNSATISFIABLE;
  	  backtracked = 1;
  	  continue;
  	}
  
        if (satisfied (ps))
  	{
  SATISFIED:
  #ifndef NDEBUG
  	  original_clauses_satisfied (ps);
  	  assumptions_satisfied (ps);
  #endif
  	  return PICOSAT_SATISFIABLE;
  	}
  
        if (backtracked)
  	{
  	  backtracked = 0;
  	  if (!ps->LEVEL && ps->isimplify < ps->fixed)
  	    iteration (ps);
  	}
  
        if (l >= 0 && count >= l)		/* decision limit reached ? */
  	return PICOSAT_UNKNOWN;
  
        if (ps->interrupt.function &&		/* external interrupt */
  	  count > 0 && !(count % INTERRUPTLIM) &&
  	  ps->interrupt.function (ps->interrupt.state))
  	return PICOSAT_UNKNOWN;
  
        if (ps->propagations >= ps->lpropagations)/* propagation limit reached ? */
  	return PICOSAT_UNKNOWN;
  
  #ifndef NADC
        if (!ps->adodisabled && ps->adoconflicts >= ps->adoconflictlimit)
  	{
  	  assert (bcp_queue_is_empty (ps));
  	  return PICOSAT_UNKNOWN;
  	}
  #endif
  
        if (ps->fsimplify < ps->fixed && ps->lsimplify <= ps->propagations)
  	{
  	  simplify (ps, 0);
  	  if (!bcp_queue_is_empty (ps))
  	    continue;
  #ifndef NFL
  	  if (ps->mtcls)
  	    return PICOSAT_UNSATISFIABLE;
  
  	  if (satisfied (ps))
  	    return PICOSAT_SATISFIABLE;
  
  	  assert (!ps->LEVEL);
  #endif
  	}
  
        if (need_to_reduce (ps))
  	reduce (ps, 50);
  
        if (ps->conflicts >= ps->lrestart && ps->LEVEL > 2)
  	restart (ps);
  
        decide (ps);
        if (ps->failed_assumption)
  	return PICOSAT_UNSATISFIABLE;
        count++;
      }
  }
  
  static void
  rebias (PS * ps)
  {
    Cls ** p, * c;
    Var * v;
  
    for (v = ps->vars + 1; v <= ps->vars + ps->max_var; v++)
      v->assigned = 0;
  
    memset (ps->jwh, 0, 2 * (ps->max_var + 1) * sizeof *ps->jwh);
  
    for (p = ps->oclauses; p < ps->ohead; p++) 
      {
        c = *p;
  
        if (!c) 
  	continue;
  
        if (c->learned)
  	continue;
  
        incjwh (ps, c);
      }
  }
  
  #ifdef TRACE
  
  static unsigned
  core (PS * ps)
  {
    unsigned idx, prev, this, delta, i, lcore, vcore;
    unsigned *stack, *shead, *eos;
    Lit **q, **eol, *lit;
    Cls *c, *reason;
    Znt *p, byte;
    Zhn *zhain;
    Var *v;
  
    assert (ps->trace);
  
    assert (ps->mtcls || ps->failed_assumption);
    if (ps->ocore >= 0)
      return ps->ocore;
  
    lcore = ps->ocore = vcore = 0;
  
    stack = shead = eos = 0;
    ENLARGE (stack, shead, eos);
  
    if (ps->mtcls)
      {
        idx = CLS2IDX (ps->mtcls);
        *shead++ = idx;
      }
    else
      {
        assert (ps->failed_assumption);
        v = LIT2VAR (ps->failed_assumption);
        reason = v->reason;
        assert (reason);
        idx = CLS2IDX (reason);
        *shead++ = idx;
      }
  
    while (shead > stack)
      {
        idx = *--shead;
        zhain = IDX2ZHN (idx);
  
        if (zhain)
  	{
  	  if (zhain->core)
  	    continue;
  
  	  zhain->core = 1;
  	  lcore++;
  
  	  c = IDX2CLS (idx);
  	  if (c)
  	    {
  	      assert (!c->core);
  	      c->core = 1;
  	    }
  
  	  i = 0;
  	  delta = 0;
  	  prev = 0;
  	  for (p = zhain->znt; (byte = *p); p++, i += 7)
  	    {
  	      delta |= (byte & 0x7f) << i;
  	      if (byte & 0x80)
  		continue;
  
  	      this = prev + delta;
  	      assert (prev < this);	/* no overflow */
  
  	      if (shead == eos)
  		ENLARGE (stack, shead, eos);
  	      *shead++ = this;
  
  	      prev = this;
  	      delta = 0;
  	      i = -7;
  	    }
  	}
        else
  	{
  	  c = IDX2CLS (idx);
  
  	  assert (c);
  	  assert (!c->learned);
  
  	  if (c->core)
  	    continue;
  
  	  c->core = 1;
  	  ps->ocore++;
  
  	  eol = end_of_lits (c);
  	  for (q = c->lits; q < eol; q++)
  	    {
  	      lit = *q;
  	      v = LIT2VAR (lit);
  	      if (v->core)
  		continue;
  
  	      v->core = 1;
  	      vcore++;
  
  	      if (!ps->failed_assumption) continue;
  	      if (lit != ps->failed_assumption) continue;
  
  	      reason = v->reason;
  	      if (!reason) continue;
  	      if (reason->core) continue;
  
  	      idx = CLS2IDX (reason);
  	      if (shead == eos)
  		ENLARGE (stack, shead, eos);
  	      *shead++ = idx;
  	    }
  	}
      }
  
    DELETEN (stack, eos - stack);
  
    if (ps->verbosity)
       fprintf (ps->out,
  	     "%s%u core variables out of %u (%.1f%%)\n"
  	     "%s%u core original clauses out of %u (%.1f%%)\n"
  	     "%s%u core learned clauses out of %u (%.1f%%)\n",
  	     ps->prefix, vcore, ps->max_var, PERCENT (vcore, ps->max_var),
  	     ps->prefix, ps->ocore, ps->oadded, PERCENT (ps->ocore, ps->oadded),
  	     ps->prefix, lcore, ps->ladded, PERCENT (lcore, ps->ladded));
  
    return ps->ocore;
  }
  
  static void
  trace_lits (PS * ps, Cls * c, FILE * file)
  {
    Lit **p, **eol = end_of_lits (c);
  
    assert (c);
    assert (c->core);
  
    for (p = c->lits; p < eol; p++)
      fprintf (file, "%d ", LIT2INT (*p));
  
    fputc ('0', file);
  }
  
  static void
  write_idx (PS * ps, unsigned idx, FILE * file)
  {
    fprintf (file, "%ld", EXPORTIDX (idx));
  }
  
  static void
  trace_clause (PS * ps, unsigned idx, Cls * c, FILE * file, int fmt)
  {
    assert (c);
    assert (c->core);
    assert (fmt == RUP_TRACE_FMT || !c->learned);
    assert (CLS2IDX (c) == idx);
  
    if (fmt != RUP_TRACE_FMT)
      {
        write_idx (ps, idx, file);
        fputc (' ', file);
      }
  
    trace_lits (ps, c, file);
  
    if (fmt != RUP_TRACE_FMT)
      fputs (" 0", file);
  
    fputc ('\n', file);
  }
  
  static void
  trace_zhain (PS * ps, unsigned idx, Zhn * zhain, FILE * file, int fmt)
  {
    unsigned prev, this, delta, i;
    Znt *p, byte;
    Cls * c;
  
    assert (zhain);
    assert (zhain->core);
  
    write_idx (ps, idx, file);
    fputc (' ', file);
  
    if (fmt == EXTENDED_TRACECHECK_TRACE_FMT)
      {
        c = IDX2CLS (idx);
        assert (c);
        trace_lits (ps, c, file);
      }
    else
      {
        assert (fmt == COMPACT_TRACECHECK_TRACE_FMT);
        putc ('*', file);
      }
  
    i = 0;
    delta = 0;
    prev = 0;
  
    for (p = zhain->znt; (byte = *p); p++, i += 7)
      {
        delta |= (byte & 0x7f) << i;
        if (byte & 0x80)
  	continue;
  
        this = prev + delta;
  
        putc (' ', file);
        write_idx (ps, this, file);
  
        prev = this;
        delta = 0;
        i = -7;
      }
  
    fputs (" 0\n", file);
  }
  
  static void
  write_core (PS * ps, FILE * file)
  {
    Lit **q, **eol;
    Cls **p, *c;
  
    fprintf (file, "p cnf %u %u\n", ps->max_var, core (ps));
  
    for (p = SOC; p != EOC; p = NXC (p))
      {
        c = *p;
  
        if (!c || c->learned || !c->core)
  	continue;
  
        eol = end_of_lits (c);
        for (q = c->lits; q < eol; q++)
  	fprintf (file, "%d ", LIT2INT (*q));
  
        fputs ("0\n", file);
      }
  }
  
  #endif
  
  static void
  write_trace (PS * ps, FILE * file, int fmt)
  {
  #ifdef TRACE
    Cls *c, ** p;
    Zhn *zhain;
    unsigned i;
  
    core (ps);
  
    if (fmt == RUP_TRACE_FMT)
      {
        ps->rupvariables = picosat_variables (ps),
        ps->rupclauses = picosat_added_original_clauses (ps);
        write_rup_header (ps, file);
      }
  
    for (p = SOC; p != EOC; p = NXC (p))
      {
        c = *p;
  
        if (ps->oclauses <= p && p < ps->eoo)
  	{
  	  i = OIDX2IDX (p - ps->oclauses);
  	  assert (!c || CLS2IDX (c) == i);
  	}
        else
  	{
            assert (ps->lclauses <= p && p < ps->EOL);
  	  i = LIDX2IDX (p - ps->lclauses);
  	}
  
        zhain = IDX2ZHN (i);
  
        if (zhain)
  	{
  	  if (zhain->core)
  	    {
  	      if (fmt == RUP_TRACE_FMT)
  		trace_clause (ps,i, c, file, fmt);
  	      else
  		trace_zhain (ps, i, zhain, file, fmt);
  	    }
  	}
        else if (c)
  	{
  	  if (fmt != RUP_TRACE_FMT && c)
  	    {
  	      if (c->core)
  		trace_clause (ps, i, c, file, fmt);
  	    }
  	}
      }
  #else
    (void) file;
    (void) fmt;
    (void) ps;
  #endif
  }
  
  static void
  write_core_wrapper (PS * ps, FILE * file, int fmt)
  {
    (void) fmt;
  #ifdef TRACE
    write_core (ps, file);
  #else
    (void) ps;
    (void) file;
  #endif
  }
  
  static Lit *
  import_lit (PS * ps, int lit, int nointernal)
  {
    Lit * res;
    Var * v;
  
    ABORTIF (lit == INT_MIN, "API usage: INT_MIN literal");
    ABORTIF (abs (lit) > (int) ps->max_var && ps->CLS != ps->clshead,
             "API usage: new variable index after 'picosat_push'");
  
    if (abs (lit) <= (int) ps->max_var)
      {
        res = int2lit (ps, lit);
        v = LIT2VAR (res);
        if (nointernal && v->internal)
  	ABORT ("API usage: trying to import invalid literal");
        else if (!nointernal && !v->internal)
  	ABORT ("API usage: trying to import invalid context");
      }
    else
      {
        while (abs (lit) > (int) ps->max_var)
  	inc_max_var (ps);
        res = int2lit (ps, lit);
      }
  
    return res;
  }
  
  #ifdef TRACE
  static void
  reset_core (PS * ps)
  {
    Cls ** p, * c;
    Zhn ** q, * z;
    unsigned i;
  
    for (i = 1; i <= ps->max_var; i++)
      ps->vars[i].core = 0;
  
    for (p = SOC; p != EOC; p = NXC (p))
      if ((c = *p))
        c->core = 0;
  
    for (q = ps->zhains; q != ps->zhead; q++)
      if ((z = *q))
        z->core = 0;
  
    ps->ocore = -1;
  }
  #endif
  
  static void
  reset_assumptions (PS * ps)
  {
    Lit ** p;
  
    ps->failed_assumption = 0;
  
    if (ps->extracted_all_failed_assumptions)
      {
        for (p = ps->als; p < ps->alshead; p++)
  	LIT2VAR (*p)->failed = 0;
  
        ps->extracted_all_failed_assumptions = 0;
      }
  
    ps->alstail = ps->alshead = ps->als;
    ps->adecidelevel = 0;
  }
  
  static void
  check_ready (PS * ps)
  {
    ABORTIF (!ps || ps->state == RESET, "API usage: uninitialized");
  }
  
  static void
  check_sat_state (PS * ps)
  {
    ABORTIF (ps->state != SAT, "API usage: expected to be in SAT state");
  }
  
  static void
  check_unsat_state (PS * ps)
  {
    ABORTIF (ps->state != UNSAT, "API usage: expected to be in UNSAT state");
  }
  
  static void
  check_sat_or_unsat_or_unknown_state (PS * ps)
  {
    ABORTIF (ps->state != SAT && ps->state != UNSAT && ps->state != UNKNOWN,
             "API usage: expected to be in SAT, UNSAT, or UNKNOWN state");
  }
  
  static void
  reset_partial (PS * ps)
  {
    unsigned idx;
    if (!ps->partial)
      return;
    for (idx = 1; idx <= ps->max_var; idx++)
      ps->vars[idx].partial = 0;
    ps->partial = 0;
  }
  
  static void
  reset_incremental_usage (PS * ps)
  {
    unsigned num_non_false;
    Lit * lit, ** q;
  
    check_sat_or_unsat_or_unknown_state (ps);
  
    LOG ( fprintf (ps->out, "%sRESET incremental usage\n", ps->prefix));
  
    if (ps->LEVEL)
      undo (ps, 0);
  
    reset_assumptions (ps);
  
    if (ps->conflict)
      { 
        num_non_false = 0;
        for (q = ps->conflict->lits; q < end_of_lits (ps->conflict); q++)
  	{
  	  lit = *q;
  	  if (lit->val != FALSE)
  	    num_non_false++;
  	}
  
        // assert (num_non_false >= 2); // TODO: why this assertion?
  #ifdef NO_BINARY_CLAUSES
        if (ps->conflict == &ps->cimpl)
  	resetcimpl (ps);
  #endif
  #ifndef NADC
        if (ps->conflict == ps->adoconflict)
  	resetadoconflict (ps);
  #endif
        ps->conflict = 0;
      }
  
  #ifdef TRACE
    reset_core (ps);
  #endif
  
    reset_partial (ps);
  
    ps->saved_flips = ps->flips;
    ps->min_flipped = UINT_MAX;
    ps->saved_max_var = ps->max_var;
  
    ps->state = READY;
  }
  
  static void
  enter (PS * ps)
  {
    if (ps->nentered++)
      return;
  
    check_ready (ps);
    ps->entered = picosat_time_stamp ();
  }
  
  static void
  leave (PS * ps)
  {
    assert (ps->nentered);
    if (--ps->nentered)
      return;
  
    sflush (ps);
  }
  
  static void
  check_trace_support_and_execute (PS * ps,
                                   FILE * file, 
  				 void (*f)(PS*,FILE*,int), int fmt)
  {
    check_ready (ps);
    check_unsat_state (ps);
  #ifdef TRACE
    ABORTIF (!ps->trace, "API usage: tracing disabled");
    enter (ps);
    f (ps, file, fmt);
    leave (ps);
  #else
    (void) file;
    (void) fmt;
    (void) f;
    ABORT ("compiled without trace support");
  #endif
  }
  
  static void
  extract_all_failed_assumptions (PS * ps)
  {
    Lit ** p, ** eol;
    Var * v, * u;
    int pos;
    Cls * c;
  
    assert (!ps->extracted_all_failed_assumptions);
  
    assert (ps->failed_assumption);
    assert (ps->mhead == ps->marked);
  
    if (ps->marked == ps->eom)
      ENLARGE (ps->marked, ps->mhead, ps->eom);
  
    v = LIT2VAR (ps->failed_assumption);
    mark_var (ps, v);
    pos = 0;
  
    while (pos < ps->mhead - ps->marked)
      {
        v = ps->marked[pos++];
        assert (v->mark);
        c = var2reason (ps, v);
        if (!c)
  	continue;
        eol = end_of_lits (c);
        for (p = c->lits; p < eol; p++)
  	{
  	  u = LIT2VAR (*p);
  	  if (!u->mark)
  	    mark_var (ps, u);
  	}
  #ifdef NO_BINARY_CLAUSES
        if (c == &ps->impl)
  	resetimpl (ps);
  #endif
      }
  
    for (p = ps->als; p < ps->alshead; p++)
      {
        u = LIT2VAR (*p);
        if (!u->mark) continue;
        u->failed = 1;
        LOG ( fprintf (ps->out,
                       "%sfailed assumption %d\n",
  		     ps->prefix, LIT2INT (*p)));
      }
  
    while (ps->mhead > ps->marked)
      (*--ps->mhead)->mark = 0;
  
    ps->extracted_all_failed_assumptions = 1;
  }
  
  const char *
  picosat_copyright (void)
  {
    return "Copyright (c) 2006 - 2014 Armin Biere JKU Linz";
  }
  
  PicoSAT *
  picosat_init (void)
  {
    return init (0, 0, 0, 0);
  }
  
  PicoSAT * 
  picosat_minit (void * pmgr,
  	       picosat_malloc pnew,
  	       picosat_realloc presize,
  	       picosat_free pfree)
  {
    ABORTIF (!pnew, "API usage: zero 'picosat_malloc' argument");
    ABORTIF (!presize, "API usage: zero 'picosat_realloc' argument");
    ABORTIF (!pfree, "API usage: zero 'picosat_free' argument");
    return init (pmgr, pnew, presize, pfree);
  }
  
  
  void
  picosat_adjust (PS * ps, int new_max_var)
  {
    unsigned new_size_vars;
  
    ABORTIF (abs (new_max_var) > (int) ps->max_var && ps->CLS != ps->clshead,
             "API usage: adjusting variable index after 'picosat_push'");
    enter (ps);
  
    new_max_var = abs (new_max_var);
    new_size_vars = new_max_var + 1;
  
    if (ps->size_vars < new_size_vars)
      enlarge (ps, new_size_vars);
  
    while (ps->max_var < (unsigned) new_max_var)
      inc_max_var (ps);
  
    leave (ps);
  }
  
  int
  picosat_inc_max_var (PS * ps)
  {
    if (ps->measurealltimeinlib)
      enter (ps);
    else
      check_ready (ps);
  
    inc_max_var (ps);
  
    if (ps->measurealltimeinlib)
      leave (ps);
  
    return ps->max_var;
  }
  
  int
  picosat_context (PS * ps)
  {
    return ps->clshead == ps->CLS ? 0 : LIT2INT (ps->clshead[-1]);
  }
  
  int
  picosat_push (PS * ps)
  {
    int res;
    Lit *lit;
    Var * v;
  
    if (ps->measurealltimeinlib)
      enter (ps);
    else
      check_ready (ps);
  
    if (ps->state != READY)
      reset_incremental_usage (ps);
  
    if (ps->rils != ps->rilshead)
      {
        res = *--ps->rilshead;
        assert (ps->vars[res].internal);
      }
    else
      {
        inc_max_var (ps);
        res = ps->max_var;
        v = ps->vars + res;
        assert (!v->internal);
        v->internal = 1;
        ps->internals++;
        LOG ( fprintf (ps->out, "%snew internal variable index %d\n", ps->prefix, res));
      }
  
    lit = int2lit (ps, res);
  
    if (ps->clshead == ps->eocls)
      ENLARGE (ps->CLS, ps->clshead, ps->eocls);
    *ps->clshead++ = lit;
  
    ps->contexts++;
  
    LOG ( fprintf (ps->out, "%snew context %d at depth %ld after push\n",
                   ps->prefix, res, (long)(ps->clshead - ps->CLS)));
  
    if (ps->measurealltimeinlib)
      leave (ps);
  
    return res;
  }
  
  int 
  picosat_pop (PS * ps)
  {
    Lit * lit;
    int res;
    ABORTIF (ps->CLS == ps->clshead, "API usage: too many 'picosat_pop'");
    ABORTIF (ps->added != ps->ahead, "API usage: incomplete clause");
  
    if (ps->measurealltimeinlib)
      enter (ps);
    else
      check_ready (ps);
  
    if (ps->state != READY)
      reset_incremental_usage (ps);
  
    assert (ps->CLS < ps->clshead);
    lit = *--ps->clshead;
    LOG ( fprintf (ps->out, "%sclosing context %d at depth %ld after pop\n",
                   ps->prefix, LIT2INT (lit), (long)(ps->clshead - ps->CLS) + 1));
  
    if (ps->cilshead == ps->eocils)
      ENLARGE (ps->cils, ps->cilshead, ps->eocils);
    *ps->cilshead++ = LIT2INT (lit);
  
    if (ps->cilshead - ps->cils > MAXCILS) {
      LOG ( fprintf (ps->out,
                    "%srecycling %ld interals with forced simplification\n",
  		  ps->prefix, (long)(ps->cilshead - ps->cils)));
      simplify (ps, 1);
    }
  
    res = picosat_context (ps);
    if (res)
      LOG ( fprintf (ps->out, "%snew context %d at depth %ld after pop\n",
  		   ps->prefix, res, (long)(ps->clshead - ps->CLS)));
    else
      LOG ( fprintf (ps->out, "%souter most context reached after pop\n", ps->prefix));
  
    if (ps->measurealltimeinlib)
      leave (ps);
    
    return res;
  }
  
  void
  picosat_set_verbosity (PS * ps, int new_verbosity_level)
  {
    check_ready (ps);
    ps->verbosity = new_verbosity_level;
  }
  
  void
  picosat_set_plain (PS * ps, int new_plain_value)
  {
    check_ready (ps);
    ps->plain = new_plain_value;
  }
  
  int
  picosat_enable_trace_generation (PS * ps)
  {
    int res = 0;
    check_ready (ps);
  #ifdef TRACE
    ABORTIF (ps->addedclauses, 
             "API usage: trace generation enabled after adding clauses");
    res = ps->trace = 1;
  #endif
    return res;
  }
  
  void
  picosat_set_incremental_rup_file (PS * ps, FILE * rup_file, int m, int n)
  {
    check_ready (ps);
    assert (!ps->rupstarted);
    ps->rup = rup_file;
    ps->rupvariables = m;
    ps->rupclauses = n;
  }
  
  void
  picosat_set_output (PS * ps, FILE * output_file)
  {
    check_ready (ps);
    ps->out = output_file;
  }
  
  void
  picosat_measure_all_calls (PS * ps)
  {
    check_ready (ps);
    ps->measurealltimeinlib = 1;
  }
  
  void
  picosat_set_prefix (PS * ps, const char * str)
  {
    check_ready (ps);
    new_prefix (ps, str);
  }
  
  void
  picosat_set_seed (PS * ps, unsigned s)
  {
    check_ready (ps);
    ps->srng = s;
  }
  
  void
  picosat_reset (PS * ps)
  {
    check_ready (ps);
    reset (ps);
  }
  
  int
  picosat_add_to_context (PS * ps, int int_lit, int context_index)
  {
    int res = ps->oadded;
    Lit *lit;
  
    if (ps->measurealltimeinlib)
      enter (ps);
    else
      check_ready (ps);
  
    ABORTIF (ps->rup && ps->rupstarted && ps->oadded >= (unsigned)ps->rupclauses,
             "API usage: adding too many clauses after RUP header written");
  #ifndef NADC
    ABORTIF (ps->addingtoado, 
             "API usage: 'picosat_add' and 'picosat_add_ado_lit' mixed");
  #endif
    if (ps->state != READY)
      reset_incremental_usage (ps);
  
    if (ps->saveorig)
      {
        if (ps->sohead == ps->eoso)
  	ENLARGE (ps->soclauses, ps->sohead, ps->eoso);
  
        *ps->sohead++ = int_lit;
      }
  
    if (int_lit)
      {
        lit = import_lit (ps, int_lit, 1);
        add_lit (ps, lit);
      }
    else
      simplify_and_add_original_clause (ps, context_index);
  
    if (ps->measurealltimeinlib)
      leave (ps);
  
    return res;
  }
  
  int
  picosat_add(PS * ps, int int_lit) {
      return picosat_add_to_context(ps, int_lit, (int) (ps->clshead - ps->CLS));
  }
  
  int
  picosat_add_arg (PS * ps, ...)
  {
    int lit;
    va_list ap;
    va_start (ap, ps);
    while ((lit = va_arg (ap, int)))
      (void) picosat_add (ps, lit);
    va_end (ap);
    return picosat_add (ps, 0);
  }
  
  int
  picosat_add_lits (PS * ps, int * lits)
  {
    const int * p;
    int lit;
    for (p = lits; (lit = *p); p++)
      (void) picosat_add (ps, lit);
    return picosat_add (ps, 0);
  }
  
  void
  picosat_add_ado_lit (PS * ps, int external_lit)
  {
  #ifndef NADC
    Lit * internal_lit;
  
    if (ps->measurealltimeinlib)
      enter (ps);
    else
      check_ready (ps);
  
    if (ps->state != READY)
      reset_incremental_usage (ps);
  
    ABORTIF (!ps->addingtoado && ps->ahead > ps->added,
             "API usage: 'picosat_add' and 'picosat_add_ado_lit' mixed");
  
    if (external_lit)
      {
        ps->addingtoado = 1;
        internal_lit = import_lit (ps, external_lit, 1);
        add_lit (ps, internal_lit);
      }
    else
      {
        ps->addingtoado = 0;
        add_ado (ps);
      }
    if (ps->measurealltimeinlib)
      leave (ps);
  #else
    (void) ps;
    (void) external_lit;
    ABORT ("compiled without all different constraint support");
  #endif
  }
  
  static void
  assume (PS * ps, Lit * lit)
  {
    if (ps->alshead == ps->eoals)
      {
        assert (ps->alstail == ps->als);
        ENLARGE (ps->als, ps->alshead, ps->eoals);
        ps->alstail = ps->als;
      }
  
    *ps->alshead++ = lit;
    LOG ( fprintf (ps->out, "%sassumption %d\n", ps->prefix, LIT2INT (lit)));
  }
  
  static void
  assume_contexts (PS * ps)
  {
    Lit ** p;
    if (ps->als != ps->alshead)
      return;
    for (p = ps->CLS; p != ps->clshead; p++)
      assume (ps, *p);
  }
  
  #ifndef RCODE
  static const char * enumstr (int i) {
    int last = i % 10;
    if (last == 1) return "st";
    if (last == 2) return "nd";
    if (last == 3) return "rd";
    return "th";
  }
  #endif
  
  static int
  tderef (PS * ps, int int_lit)
  {
    Lit * lit;
    Var * v;
  
    assert (abs (int_lit) <= (int) ps->max_var);
  
    lit = int2lit (ps, int_lit);
  
    v = LIT2VAR (lit);
    if (v->level > 0)
      return 0;
  
    if (lit->val == TRUE)
      return 1;
  
    if (lit->val == FALSE)
      return -1;
  
    return 0;
  }
  
  static int
  pderef (PS * ps, int int_lit)
  {
    Lit * lit;
    Var * v;
  
    assert (abs (int_lit) <= (int) ps->max_var);
  
    v = ps->vars + abs (int_lit);
    if (!v->partial)
      return 0;
  
    lit = int2lit (ps, int_lit);
  
    if (lit->val == TRUE)
      return 1;
  
    if (lit->val == FALSE)
      return -1;
  
    return 0;
  }
  
  static void
  minautarky (PS * ps)
  {
    unsigned * occs, maxoccs, tmpoccs, npartial;
    int * p, * c, lit, best, val;
  #ifdef LOGGING
    int tl;
  #endif
  
    assert (!ps->partial);
  
    npartial = 0;
  
    NEWN (occs, 2*ps->max_var + 1);
    CLRN (occs, 2*ps->max_var + 1);
    occs += ps->max_var;
    for (p = ps->soclauses; p < ps->sohead; p++)
      occs[*p]++;
    assert (occs[0] == ps->oadded);
  
    for (c = ps->soclauses; c < ps->sohead; c = p + 1) 
      {
  #ifdef LOGGING
        tl = 0;
  #endif
        best = 0; 
        maxoccs = 0;
        for (p = c; (lit = *p); p++)
  	{
  	  val = tderef (ps, lit);
  	  if (val < 0)
  	    continue;
  	  if (val > 0)
  	    {
  #ifdef LOGGING
  	      tl = 1;
  #endif
  	      best = lit;
  	      maxoccs = occs[lit];
  	    }
  
  	  val = pderef (ps, lit);
  	  if (val > 0)
  	    break;
  	  if (val < 0)
  	    continue;
  	  val = int2lit (ps, lit)->val;
  	  assert (val);
  	  if (val < 0)
  	    continue;
  	  tmpoccs = occs[lit];
  	  if (best && tmpoccs <= maxoccs)
  	    continue;
  	  best = lit;
  	  maxoccs = tmpoccs;
  	}
        if (!lit)
  	{
  	  assert (best);
  	  LOG ( fprintf (ps->out, "%sautark %d with %d occs%s\n", 
  	       ps->prefix, best, maxoccs, tl ? " (top)" : ""));
  	  ps->vars[abs (best)].partial = 1;
  	  npartial++;
  	}
        for (p = c; (lit = *p); p++)
  	{
  	  assert (occs[lit] > 0);
  	  occs[lit]--;
  	}
      }
    occs -= ps->max_var;
    DELETEN (occs, 2*ps->max_var + 1);
    ps->partial = 1;
  
    if (ps->verbosity)
       fprintf (ps->out,
        "%sautarky of size %u out of %u satisfying all clauses (%.1f%%)\n",
        ps->prefix, npartial, ps->max_var, PERCENT (npartial, ps->max_var));
  }
  
  void
  picosat_assume (PS * ps, int int_lit)
  {
    Lit *lit;
  
    if (ps->measurealltimeinlib)
      enter (ps);
    else
      check_ready (ps);
  
    if (ps->state != READY)
      reset_incremental_usage (ps);
  
    assume_contexts (ps);
    lit = import_lit (ps, int_lit, 1);
    assume (ps, lit);
  
    if (ps->measurealltimeinlib)
      leave (ps);
  }
  
  int
  picosat_sat (PS * ps, int l)
  {
    int res;
    char ch;
  
    enter (ps);
  
    ps->calls++;
    LOG ( fprintf (ps->out, "%sSTART call %u\n", ps->prefix, ps->calls));
  
    if (ps->added < ps->ahead)
      {
  #ifndef NADC
        if (ps->addingtoado)
  	ABORT ("API usage: incomplete all different constraint");
        else
  #endif
  	ABORT ("API usage: incomplete clause");
      }
  
    if (ps->state != READY)
      reset_incremental_usage (ps);
  
    assume_contexts (ps);
  
    res = sat (ps, l);
  
    assert (ps->state == READY);
  
    switch (res)
      {
      case PICOSAT_UNSATISFIABLE:
        ch = '0';
        ps->state = UNSAT;
        break;
      case PICOSAT_SATISFIABLE:
        ch = '1';
        ps->state = SAT;
        break;
      default:
        ch = '?';
        ps->state = UNKNOWN;
        break;
      }
  
    if (ps->verbosity)
      {
        report (ps, 1, ch);
        rheader (ps);
      }
  
    leave (ps);
    LOG ( fprintf (ps->out, "%sEND call %u result %d\n", ps->prefix, ps->calls, res));
  
    ps->last_sat_call_result = res;
  
    return res;
  }
  
  int
  picosat_res (PS * ps)
  {
    return ps->last_sat_call_result;
  }
  
  int
  picosat_deref (PS * ps, int int_lit)
  {
    Lit *lit;
  
    check_ready (ps);
    check_sat_state (ps);
    ABORTIF (!int_lit, "API usage: can not deref zero literal");
    ABORTIF (ps->mtcls, "API usage: deref after empty clause generated");
  
  #ifdef STATS
    ps->derefs++;
  #endif
  
    if (abs (int_lit) > (int) ps->max_var)
      return 0;
  
    lit = int2lit (ps, int_lit);
  
    if (lit->val == TRUE)
      return 1;
  
    if (lit->val == FALSE)
      return -1;
  
    return 0;
  }
  
  int
  picosat_deref_toplevel (PS * ps, int int_lit)
  {
    check_ready (ps);
    ABORTIF (!int_lit, "API usage: can not deref zero literal");
  
  #ifdef STATS
    ps->derefs++;
  #endif
    if (abs (int_lit) > (int) ps->max_var)
      return 0;
  
    return tderef (ps, int_lit);
  }
  
  int
  picosat_inconsistent (PS * ps)
  {
    check_ready (ps);
    return ps->mtcls != 0;
  }
  
  int
  picosat_corelit (PS * ps, int int_lit)
  {
    check_ready (ps);
    check_unsat_state (ps);
    ABORTIF (!int_lit, "API usage: zero literal can not be in core");
  
    assert (ps->mtcls || ps->failed_assumption);
  
  #ifdef TRACE
    {
      int res = 0;
      ABORTIF (!ps->trace, "tracing disabled");
      if (ps->measurealltimeinlib)
        enter (ps);
      core (ps);
      if (abs (int_lit) <= (int) ps->max_var)
        res = ps->vars[abs (int_lit)].core;
      assert (!res || ps->failed_assumption || ps->vars[abs (int_lit)].used);
      if (ps->measurealltimeinlib)
        leave (ps);
      return res;
    }
  #else
    ABORT ("compiled without trace support");
    return 0;
  #endif
  }
  
  int
  picosat_coreclause (PS * ps, int ocls)
  {
    check_ready (ps);
    check_unsat_state (ps);
  
    ABORTIF (ocls < 0, "API usage: negative original clause index");
    ABORTIF (ocls >= (int)ps->oadded, "API usage: original clause index exceeded");
  
    assert (ps->mtcls || ps->failed_assumption);
  
  #ifdef TRACE
    {
      Cls ** clsptr, * c;
      int res  = 0;
  
      ABORTIF (!ps->trace, "tracing disabled");
      if (ps->measurealltimeinlib)
        enter (ps);
      core (ps);
      clsptr = ps->oclauses + ocls;
      assert (clsptr < ps->ohead);
      c = *clsptr;
      if (c) 
        res = c->core;
      if (ps->measurealltimeinlib)
        leave (ps);
  
      return res;
    }
  #else
    ABORT ("compiled without trace support");
    return 0;
  #endif
  }
  
  int
  picosat_failed_assumption (PS * ps, int int_lit)
  {
    Lit * lit;
    Var * v;
    ABORTIF (!int_lit, "API usage: zero literal as assumption");
    check_ready (ps);
    check_unsat_state (ps);
    if (ps->mtcls)
      return 0;
    assert (ps->failed_assumption);
    if (abs (int_lit) > (int) ps->max_var)
      return 0;
    if (!ps->extracted_all_failed_assumptions)
      extract_all_failed_assumptions (ps);
    lit = import_lit (ps, int_lit, 1);
    v = LIT2VAR (lit);
    return v->failed;
  }
  
  int
  picosat_failed_context (PS * ps, int int_lit)
  {
    Lit * lit;
    Var * v;
    ABORTIF (!int_lit, "API usage: zero literal as context");
    ABORTIF (abs (int_lit) > (int) ps->max_var, "API usage: invalid context");
    check_ready (ps);
    check_unsat_state (ps);
    assert (ps->failed_assumption);
    if (!ps->extracted_all_failed_assumptions)
      extract_all_failed_assumptions (ps);
    lit = import_lit (ps, int_lit, 0);
    v = LIT2VAR (lit);
    return v->failed;
  }
  
  const int *
  picosat_failed_assumptions (PS * ps)
  {
    Lit ** p, * lit;
    Var * v;
    int ilit;
  
    ps->falshead = ps->fals;
    check_ready (ps);
    check_unsat_state (ps);
    if (!ps->mtcls) 
      {
        assert (ps->failed_assumption);
        if (!ps->extracted_all_failed_assumptions)
  	extract_all_failed_assumptions (ps);
  
        for (p = ps->als; p < ps->alshead; p++)
  	{
  	  lit = *p;
  	  v = LIT2VAR (*p);
  	  if (!v->failed)
  	    continue;
  	  ilit = LIT2INT (lit);
  	  if (ps->falshead == ps->eofals)
  	    ENLARGE (ps->fals, ps->falshead, ps->eofals);
  	  *ps->falshead++ = ilit;
  	}
      }
    if (ps->falshead == ps->eofals)
      ENLARGE (ps->fals, ps->falshead, ps->eofals);
    *ps->falshead++ = 0;
    return ps->fals;
  }
  
  const int *
  picosat_mus_assumptions (PS * ps, void * s, void (*cb)(void*,const int*), int fix)
  {
    int i, j, ilit, len, nwork, * work, res;
    signed char * redundant;
    Lit ** p, * lit;
    int failed;
    Var * v;
  #ifndef NDEBUG
    int oldlen;
  #endif
  #ifndef RCODE
    int norig = ps->alshead - ps->als; 
  #endif
  
    check_ready (ps);
    check_unsat_state (ps);
    len = 0;
    if (!ps->mtcls) 
      {
        assert (ps->failed_assumption);
        if (!ps->extracted_all_failed_assumptions)
  	extract_all_failed_assumptions (ps);
  
        for (p = ps->als; p < ps->alshead; p++)
  	if (LIT2VAR (*p)->failed)
  	  len++;
      }
  
    if (ps->mass)
      DELETEN (ps->mass, ps->szmass);
    ps->szmass = len + 1;
    NEWN (ps->mass, ps->szmass);
  
    i = 0;
    for (p = ps->als; p < ps->alshead; p++)
      {
        lit = *p;
        v = LIT2VAR (lit);
        if (!v->failed)
  	continue;
        ilit = LIT2INT (lit);
        assert (i < len);
        ps->mass[i++] = ilit;
      }
    assert (i == len);
    ps->mass[i] = 0;
    if (ps->verbosity)
       fprintf (ps->out, 
        "%sinitial set of failed assumptions of size %d out of %d (%.0f%%)\n",
        ps->prefix, len, norig, PERCENT (len, norig));
    if (cb)
      cb (s, ps->mass);
  
    nwork = len;
    NEWN (work, nwork);
    for (i = 0; i < len; i++)
      work[i] = ps->mass[i];
  
    NEWN (redundant, nwork);
    CLRN (redundant, nwork);
  
    for (i = 0; i < nwork; i++)
      {
        if (redundant[i])
  	continue;
  
        if (ps->verbosity > 1)
  	 fprintf (ps->out,
  	         "%strying to drop %d%s assumption %d\n", 
  		 ps->prefix, i, enumstr (i), work[i]);
        for (j = 0; j < nwork; j++)
  	{
  	  if (i == j) continue;
  	  if (j < i && fix) continue;
  	  if (redundant[j]) continue;
  	  picosat_assume (ps, work[j]);
  	}
  
        res = picosat_sat (ps, -1);
        if (res == 10)
  	{
  	  if (ps->verbosity > 1)
  	     fprintf (ps->out,
  		     "%sfailed to drop %d%s assumption %d\n", 
  		     ps->prefix, i, enumstr (i), work[i]);
  
  	  if (fix)
  	    {
  	      picosat_add (ps, work[i]);
  	      picosat_add (ps, 0);
  	    }
  	}
        else
  	{
  	  assert (res == 20);
  	  if (ps->verbosity > 1)
  	     fprintf (ps->out,
  		     "%ssuceeded to drop %d%s assumption %d\n", 
  		     ps->prefix, i, enumstr (i), work[i]);
  	  redundant[i] = 1;
  	  for (j = 0; j < nwork; j++)
  	    {
  	      failed = picosat_failed_assumption (ps, work[j]);
  	      if (j <= i) 
  		{
  		  assert ((j < i && fix) || redundant[j] == !failed);
  		  continue;
  		}
  
  	      if (!failed)
  		{
  		  redundant[j] = -1;
  		  if (ps->verbosity > 1)
  		     fprintf (ps->out,
  			     "%salso suceeded to drop %d%s assumption %d\n", 
  			     ps->prefix, j, enumstr (j), work[j]);
  		}
  	    }
  
  #ifndef NDEBUG
  	    oldlen = len;
  #endif
  	    len = 0;
  	    for (j = 0; j < nwork; j++)
  	      if (!redundant[j])
  		ps->mass[len++] = work[j];
  	    ps->mass[len] = 0;
  	    assert (len < oldlen);
  
  	    if (fix)
  	      {
  		picosat_add (ps, -work[i]);
  		picosat_add (ps, 0);
  	      }
  
  #ifndef NDEBUG
  	    for (j = 0; j <= i; j++)
  	      assert (redundant[j] >= 0);
  #endif
  	    for (j = i + 1; j < nwork; j++) 
  	      {
  		if (redundant[j] >= 0)
  		  continue;
  
  		if (fix)
  		  {
  		    picosat_add (ps, -work[j]);
  		    picosat_add (ps, 0);
  		  }
  
  		redundant[j] = 1;
  	      }
  
  	    if (ps->verbosity)
  	       fprintf (ps->out, 
  	"%sreduced set of failed assumptions of size %d out of %d (%.0f%%)\n",
  		ps->prefix, len, norig, PERCENT (len, norig));
  	    if (cb)
  	      cb (s, ps->mass);
  	}
      }
  
    DELETEN (work, nwork);
    DELETEN (redundant, nwork);
  
    if (ps->verbosity)
      {
         fprintf (ps->out, "%sreinitializing unsat state\n", ps->prefix);
        fflush (ps->out);
      }
  
    for (i = 0; i < len; i++)
      picosat_assume (ps, ps->mass[i]);
  
  #ifndef NDEBUG
    res = 
  #endif
    picosat_sat (ps, -1);
    assert (res == 20);
  
    if (!ps->mtcls)
      {
        assert (!ps->extracted_all_failed_assumptions);
        extract_all_failed_assumptions (ps);
      }
  
    return ps->mass;
  }
  
  static const int *
  mss (PS * ps, int * a, int size)
  {
    int i, j, k, res;
  
    assert (!ps->mtcls);
  
    if (ps->szmssass)
      DELETEN (ps->mssass, ps->szmssass);
  
    ps->szmssass = 0;
    ps->mssass = 0;
  
    ps->szmssass = size + 1;
    NEWN (ps->mssass, ps->szmssass);
  
    LOG ( fprintf (ps->out, "%ssearch MSS over %d assumptions\n", ps->prefix, size));
  
    k = 0;
    for (i = k; i < size; i++)
      {
        for (j = 0; j < k; j++)
  	picosat_assume (ps, ps->mssass[j]);
  
        LOG ( fprintf (ps->out, 
               "%strying to add assumption %d to MSS : %d\n", 
  	     ps->prefix, i, a[i])); 
  
        picosat_assume (ps, a[i]);
  
        res = picosat_sat (ps, -1);
        if (res == 10)
  	{
  	  LOG ( fprintf (ps->out, 
  		 "%sadding assumption %d to MSS : %d\n", ps->prefix, i, a[i])); 
  
  	  ps->mssass[k++] = a[i];
  
  	  for (j = i + 1; j < size; j++)
  	    {
  	      if (picosat_deref (ps, a[j]) <= 0)
  		continue;
  
  	      LOG ( fprintf (ps->out, 
  		     "%salso adding assumption %d to MSS : %d\n", 
  		     ps->prefix, j, a[j])); 
  
  	      ps->mssass[k++] = a[j];
  
  	      if (++i != j)
  		{
  		  int tmp = a[i];
  		  a[i] = a[j];
  		  a[j] = tmp;
  		}
  	    }
  	}
        else
  	{
  	  assert (res == 20);
  
  	  LOG ( fprintf (ps->out, 
  		 "%signoring assumption %d in MSS : %d\n", ps->prefix, i, a[i])); 
  	}
      }
    ps->mssass[k] = 0;
    LOG ( fprintf (ps->out, "%sfound MSS of size %d\n", ps->prefix, k));
  
    return ps->mssass;
  }
  
  static void
  reassume (PS * ps, const int * a, int size)
  {
    int i;
    LOG ( fprintf (ps->out, "%sreassuming all assumptions\n", ps->prefix));
    for (i = 0; i < size; i++)
      picosat_assume (ps, a[i]);
  }
  
  const int *
  picosat_maximal_satisfiable_subset_of_assumptions (PS * ps)
  {
    const int * res;
    int i, *a, size;
  
    ABORTIF (ps->mtcls,
             "API usage: CNF inconsistent (use 'picosat_inconsistent')");
  
    enter (ps);
  
    size = ps->alshead - ps->als;
    NEWN (a, size);
  
    for (i = 0; i < size; i++)
      a[i] = LIT2INT (ps->als[i]);
  
    res = mss (ps, a, size);
    reassume (ps, a, size);
  
    DELETEN (a, size);
  
    leave (ps);
  
    return res;
  }
  
  static void
  check_mss_flags_clean (PS * ps)
  {
  #ifndef NDEBUG
    unsigned i;
    for (i = 1; i <= ps->max_var; i++)
      {
        assert (!ps->vars[i].msspos);
        assert (!ps->vars[i].mssneg);
      }
  #else
    (void) ps;
  #endif
  }
  
  static void
  push_mcsass (PS * ps, int lit)
  {
    if (ps->nmcsass == ps->szmcsass)
      {
        ps->szmcsass = ps->szmcsass ? 2*ps->szmcsass : 1;
        RESIZEN (ps->mcsass, ps->nmcsass, ps->szmcsass);
      }
  
    ps->mcsass[ps->nmcsass++] = lit;
  }
  
  static const int *
  next_mss (PS * ps, int mcs)
  {
    int i, *a, size, mssize, mcsize, lit, inmss;
    const int * res, * p;
    Var * v;
  
    if (ps->mtcls) return 0;
  
    check_mss_flags_clean (ps);
  
    if (mcs && ps->mcsass)
      {
        DELETEN (ps->mcsass, ps->szmcsass);
        ps->nmcsass = ps->szmcsass = 0;
        ps->mcsass = 0;
      }
  
    size = ps->alshead - ps->als;
    NEWN (a, size);
  
    for (i = 0; i < size; i++)
      a[i] = LIT2INT (ps->als[i]);
  
    (void) picosat_sat (ps, -1);
  
    //TODO short cut for 'picosat_res () == 10'?
  
    if (ps->mtcls)
      {
        assert (picosat_res (ps) == 20);
        res = 0;
        goto DONE;
      }
  
    res = mss (ps, a, size);
  
    if (ps->mtcls)
      {
        res = 0;
        goto DONE;
      }
  
    for (p = res; (lit = *p); p++) 
      {
        v = ps->vars + abs (lit);
        if (lit < 0)
  	{
  	  assert (!v->msspos);
  	  v->mssneg = 1;
  	}
        else
  	{
  	  assert (!v->mssneg);
  	  v->msspos = 1;
  	}
      }
  
    mssize = p - res;
    mcsize = INT_MIN;
  
    for (i = 0; i < size; i++)
      {
        lit = a[i];
        v = ps->vars + abs (lit);
        if (lit > 0 && v->msspos)
  	inmss = 1;
        else if (lit < 0 && v->mssneg)
  	inmss = 1;
        else 
  	inmss = 0;
  
        if (mssize < mcsize)
  	{
  	  if (inmss)
  	    picosat_add (ps, -lit);
  	}
        else
  	{
  	  if (!inmss)
  	    picosat_add (ps, lit);
  	}
  
        if (!inmss && mcs)
  	push_mcsass (ps, lit);
      }
    picosat_add (ps, 0);
    if (mcs)
      push_mcsass (ps, 0);
  
    for (i = 0; i < size; i++)
      {
        lit = a[i];
        v = ps->vars + abs (lit);
        v->msspos = 0;
        v->mssneg = 0;
      }
  
  DONE:
  
    reassume (ps, a, size);
    DELETEN (a, size);
  
    return res;
  }
  
  const int *
  picosat_next_maximal_satisfiable_subset_of_assumptions (PS * ps)
  {
    const int * res;
    enter (ps);
    res = next_mss (ps, 0);
    leave (ps);
    return  res;
  }
  
  const int *
  picosat_next_minimal_correcting_subset_of_assumptions (PS * ps)
  {
    const int * res, * tmp;
    enter (ps);
    tmp = next_mss (ps, 1);
    res = tmp ? ps->mcsass : 0;
    leave (ps);
    return res;
  }
  
  const int *
  picosat_humus (PS * ps, 
                 void (*callback)(void*state,int nmcs,int nhumus),
  	       void * state)
  {
    int lit, nmcs, j, nhumus;
    const int * mcs, * p;
    unsigned i;
    Var * v;
    enter (ps);
  #ifndef NDEBUG
    for (i = 1; i <= ps->max_var; i++)
      {
        v = ps->vars + i;
        assert (!v->humuspos);
        assert (!v->humusneg);
      }
  #endif
    nhumus = nmcs = 0;
    while ((mcs = picosat_next_minimal_correcting_subset_of_assumptions (ps)))
      {
        for (p = mcs; (lit = *p); p++)
  	{
  	  v = ps->vars + abs (lit);
  	  if (lit < 0)
  	    {
  	      if (!v->humusneg)
  		{
  		  v->humusneg = 1;
  		  nhumus++;
  		}
  	    }
  	  else
  	    {
  	      if (!v->humuspos)
  		{
  		  v->humuspos = 1;
  		  nhumus++;
  		}
  	    }
  	}
        nmcs++;
        LOG ( fprintf (ps->out, 
               "%smcs %d of size %d humus %d\n",
  	     ps->prefix, nmcs, (int)(p - mcs), nhumus));
        if (callback)
  	callback (state, nmcs, nhumus);
      }
    assert (!ps->szhumus);
    ps->szhumus = 1;
    for (i = 1; i <= ps->max_var; i++)
      {
        v = ps->vars + i;
        if (v->humuspos)
  	ps->szhumus++;
        if (v->humusneg)
  	ps->szhumus++;
      }
    assert (nhumus + 1 == ps->szhumus);
    NEWN (ps->humus, ps->szhumus);
    j = 0;
    for (i = 1; i <= ps->max_var; i++)
      {
        v = ps->vars + i;
        if (v->humuspos)
  	{
  	  assert (j < nhumus);
  	  ps->humus[j++] = (int) i;
  	}
        if (v->humusneg)
  	{
  	  assert (j < nhumus);
  	  assert (i < INT_MAX);
  	  ps->humus[j++] = - (int) i;
  	}
      }
    assert (j == nhumus);
    assert (j < ps->szhumus);
    ps->humus[j] = 0;
    leave (ps);
    return ps->humus;
  }
  
  int
  picosat_usedlit (PS * ps, int int_lit)
  {
    int res;
    check_ready (ps);
    check_sat_or_unsat_or_unknown_state (ps);
    ABORTIF (!int_lit, "API usage: zero literal can not be used");
    int_lit = abs (int_lit);
    res = (int_lit <= (int) ps->max_var) ? ps->vars[int_lit].used : 0;
    return res;
  }
  
  void
  picosat_write_clausal_core (PS * ps, FILE * file)
  {
    check_trace_support_and_execute (ps, file, write_core_wrapper, 0);
  }
  
  void
  picosat_write_compact_trace (PS * ps, FILE * file)
  {
    check_trace_support_and_execute (ps, file, write_trace,
                                     COMPACT_TRACECHECK_TRACE_FMT);
  }
  
  void
  picosat_write_extended_trace (PS * ps, FILE * file)
  {
    check_trace_support_and_execute (ps, file, write_trace,
                                     EXTENDED_TRACECHECK_TRACE_FMT);
  }
  
  void
  picosat_write_rup_trace (PS * ps, FILE * file)
  {
    check_trace_support_and_execute (ps, file, write_trace, RUP_TRACE_FMT);
  }
  
  size_t
  picosat_max_bytes_allocated (PS * ps)
  {
    check_ready (ps);
    return ps->max_bytes;
  }
  
  void
  picosat_set_propagation_limit (PS * ps, unsigned long long l)
  {
    ps->lpropagations = l;
  }
  
  unsigned long long
  picosat_propagations (PS * ps)
  {
    return ps->propagations;
  }
  
  unsigned long long
  picosat_visits (PS * ps)
  {
    return ps->visits;
  }
  
  unsigned long long
  picosat_decisions (PS * ps)
  {
    return ps->decisions;
  }
  
  int
  picosat_variables (PS * ps)
  {
    check_ready (ps);
    return (int) ps->max_var;
  }
  
  int
  picosat_added_original_clauses (PS * ps)
  {
    check_ready (ps);
    return (int) ps->oadded;
  }
  
  void
  picosat_stats (PS * ps)
  {
  #ifndef RCODE
    unsigned redlits;
  #endif
  #ifdef STATS
    check_ready (ps);
    assert (ps->sdecisions + ps->rdecisions + ps->assumptions == ps->decisions);
  #endif
    if (ps->calls > 1)
       fprintf (ps->out, "%s%u calls\n", ps->prefix, ps->calls);
    if (ps->contexts)
      {
         fprintf (ps->out, "%s%u contexts", ps->prefix, ps->contexts);
  #ifdef STATS
         fprintf (ps->out, " %u internal variables", ps->internals);
  #endif
         fprintf (ps->out, "\n");
      }
     fprintf (ps->out, "%s%u iterations\n", ps->prefix, ps->iterations);
     fprintf (ps->out, "%s%u restarts", ps->prefix, ps->restarts);
  #ifdef STATS
     fprintf (ps->out, " (%u skipped)", ps->skippedrestarts);
  #endif
    fputc ('\n', ps->out);
  #ifndef NFL
     fprintf (ps->out, "%s%u failed literals", ps->prefix, ps->failedlits);
  #ifdef STATS
     fprintf (ps->out,
             ", %u calls, %u rounds, %llu propagations",
             ps->flcalls, ps->flrounds, ps->flprops);
  #endif
    fputc ('\n', ps->out);
  #ifdef STATS
     fprintf (ps->out, 
      "%sfl: %u = %.1f%% implicit, %llu oopsed, %llu tried, %llu skipped\n", 
      ps->prefix, 
      ps->ifailedlits, PERCENT (ps->ifailedlits, ps->failedlits),
      ps->floopsed, ps->fltried, ps->flskipped);
  #endif
  #endif
     fprintf (ps->out, "%s%u conflicts", ps->prefix, ps->conflicts);
  #ifdef STATS
     fprintf (ps->out, " (%u uips = %.1f%%)\n", ps->uips, PERCENT(ps->uips,ps->conflicts));
  #else
    fputc ('\n', ps->out);
  #endif
  #ifndef NADC
     fprintf (ps->out, "%s%u adc conflicts\n", ps->prefix, ps->adoconflicts);
  #endif
  #ifdef STATS
     fprintf (ps->out, "%s%llu dereferenced literals\n", ps->prefix, ps->derefs);
  #endif
     fprintf (ps->out, "%s%u decisions", ps->prefix, ps->decisions);
  #ifdef STATS
     fprintf (ps->out, " (%u random = %.2f%%",
             ps->rdecisions, PERCENT (ps->rdecisions, ps->decisions));
     fprintf (ps->out, ", %u assumptions", ps->assumptions);
    fputc (')', ps->out);
  #endif
    fputc ('\n', ps->out);
  #ifdef STATS
     fprintf (ps->out,
             "%s%u static phase decisions (%.1f%% of all variables)\n",
  	   ps->prefix,
  	   ps->staticphasedecisions, PERCENT (ps->staticphasedecisions, ps->max_var));
  #endif
     fprintf (ps->out, "%s%u fixed variables\n", ps->prefix, ps->fixed);
    assert (ps->nonminimizedllits >= ps->minimizedllits);
  #ifndef RCODE
    redlits = ps->nonminimizedllits - ps->minimizedllits;
  #endif
     fprintf (ps->out, "%s%u learned literals\n", ps->prefix, ps->llitsadded);
     fprintf (ps->out, "%s%.1f%% deleted literals\n",
       ps->prefix, PERCENT (redlits, ps->nonminimizedllits));
  
  #ifdef STATS
  #ifdef TRACE
     fprintf (ps->out,
  	   "%s%llu antecedents (%.1f antecedents per clause",
  	   ps->prefix, ps->antecedents, AVERAGE (ps->antecedents, ps->conflicts));
    if (ps->trace)
       fprintf (ps->out, ", %.1f bytes/antecedent)", AVERAGE (ps->znts, ps->antecedents));
    fputs (")\n", ps->out);
  #endif
  
     fprintf (ps->out, "%s%llu propagations (%.1f propagations per decision)\n",
             ps->prefix, ps->propagations, AVERAGE (ps->propagations, ps->decisions));
     fprintf (ps->out, "%s%llu visits (%.1f per propagation)\n",
  	   ps->prefix, ps->visits, AVERAGE (ps->visits, ps->propagations));
     fprintf (ps->out, 
             "%s%llu binary clauses visited (%.1f%% %.1f per propagation)\n",
  	   ps->prefix, ps->bvisits, 
  	   PERCENT (ps->bvisits, ps->visits),
  	   AVERAGE (ps->bvisits, ps->propagations));
     fprintf (ps->out, 
             "%s%llu ternary clauses visited (%.1f%% %.1f per propagation)\n",
  	   ps->prefix, ps->tvisits, 
  	   PERCENT (ps->tvisits, ps->visits),
  	   AVERAGE (ps->tvisits, ps->propagations));
     fprintf (ps->out, 
             "%s%llu large clauses visited (%.1f%% %.1f per propagation)\n",
  	   ps->prefix, ps->lvisits, 
  	   PERCENT (ps->lvisits, ps->visits),
  	   AVERAGE (ps->lvisits, ps->propagations));
     fprintf (ps->out, "%s%llu other true (%.1f%% of visited clauses)\n",
  	   ps->prefix, ps->othertrue, PERCENT (ps->othertrue, ps->visits));
     fprintf (ps->out, 
             "%s%llu other true in binary clauses (%.1f%%)"
  	   ", %llu upper (%.1f%%)\n",
             ps->prefix, ps->othertrue2, PERCENT (ps->othertrue2, ps->othertrue),
  	   ps->othertrue2u, PERCENT (ps->othertrue2u, ps->othertrue2));
     fprintf (ps->out, 
             "%s%llu other true in large clauses (%.1f%%)"
  	   ", %llu upper (%.1f%%)\n",
             ps->prefix, ps->othertruel, PERCENT (ps->othertruel, ps->othertrue),
  	   ps->othertruelu, PERCENT (ps->othertruelu, ps->othertruel));
     fprintf (ps->out, "%s%llu ternary and large traversals (%.1f per visit)\n",
  	   ps->prefix, ps->traversals, AVERAGE (ps->traversals, ps->visits));
     fprintf (ps->out, "%s%llu large traversals (%.1f per large visit)\n",
  	   ps->prefix, ps->ltraversals, AVERAGE (ps->ltraversals, ps->lvisits));
     fprintf (ps->out, "%s%llu assignments\n", ps->prefix, ps->assignments);
  #else
     fprintf (ps->out, "%s%llu propagations\n", ps->prefix, picosat_propagations (ps));
     fprintf (ps->out, "%s%llu visits\n", ps->prefix, picosat_visits (ps));
  #endif
     fprintf (ps->out, "%s%.1f%% variables used\n", ps->prefix, PERCENT (ps->vused, ps->max_var));
  
    sflush (ps);
     fprintf (ps->out, "%s%.1f seconds in library\n", ps->prefix, ps->seconds);
     fprintf (ps->out, "%s%.1f megaprops/second\n",
  	   ps->prefix, AVERAGE (ps->propagations / 1e6f, ps->seconds));
     fprintf (ps->out, "%s%.1f megavisits/second\n",
  	   ps->prefix, AVERAGE (ps->visits / 1e6f, ps->seconds));
     fprintf (ps->out, "%sprobing %.1f seconds %.0f%%\n",
             ps->prefix, ps->flseconds, PERCENT (ps->flseconds, ps->seconds));
  #ifdef STATS
     fprintf (ps->out,
  	   "%srecycled %.1f MB in %u reductions\n",
  	   ps->prefix, ps->rrecycled / (double) (1 << 20), ps->reductions);
     fprintf (ps->out,
  	   "%srecycled %.1f MB in %u simplifications\n",
  	   ps->prefix, ps->srecycled / (double) (1 << 20), ps->simps);
  #else
     fprintf (ps->out, "%s%u simplifications\n", ps->prefix, ps->simps);
     fprintf (ps->out, "%s%u reductions\n", ps->prefix, ps->reductions);
     fprintf (ps->out, "%s%.1f MB recycled\n", ps->prefix, ps->recycled / (double) (1 << 20));
  #endif
     fprintf (ps->out, "%s%.1f MB maximally allocated\n",
  	    ps->prefix, picosat_max_bytes_allocated (ps) / (double) (1 << 20));
  }
  
  #ifndef NGETRUSAGE
  #include <sys/time.h>
  #include <sys/resource.h>
  #include <sys/unistd.h>
  #endif
  
  double
  picosat_time_stamp (void)
  {
    double res = -1;
  #ifndef NGETRUSAGE
    struct rusage u;
    res = 0;
    if (!getrusage (RUSAGE_SELF, &u))
      {
        res += u.ru_utime.tv_sec + 1e-6 * u.ru_utime.tv_usec;
        res += u.ru_stime.tv_sec + 1e-6 * u.ru_stime.tv_usec;
      }
  #endif
    return res;
  }
  
  double
  picosat_seconds (PS * ps)
  {
    check_ready (ps);
    return ps->seconds;
  }
  
  void
  picosat_print (PS * ps, FILE * file)
  {
  #ifdef NO_BINARY_CLAUSES
    Lit * lit, *other, * last;
    Ltk * stack;
  #endif
    Lit **q, **eol;
    Cls **p, *c;
    unsigned n;
  
    if (ps->measurealltimeinlib)
      enter (ps);
    else
      check_ready (ps);
  
    n = 0;
    n +=  ps->alshead - ps->als;
  
    for (p = SOC; p != EOC; p = NXC (p))
      {
        c = *p;
  
        if (!c)
  	continue;
  
  #ifdef TRACE
        if (c->collected)
  	continue;
  #endif
        n++;
      }
  
  #ifdef NO_BINARY_CLAUSES
    last = int2lit (ps, -ps->max_var);
    for (lit = int2lit (ps, 1); lit <= last; lit++)
      {
        stack = LIT2IMPLS (lit);
        eol = stack->start + stack->count;
        for (q = stack->start; q < eol; q++)
  	if (*q >= lit)
  	  n++;
      }
  #endif
  
    fprintf (file, "p cnf %d %u\n", ps->max_var, n);
  
    for (p = SOC; p != EOC; p = NXC (p))
      {
        c = *p;
        if (!c)
  	continue;
  
  #ifdef TRACE
        if (c->collected)
  	continue;
  #endif
  
        eol = end_of_lits (c);
        for (q = c->lits; q < eol; q++)
  	fprintf (file, "%d ", LIT2INT (*q));
  
        fputs ("0\n", file);
      }
  
  #ifdef NO_BINARY_CLAUSES
    last = int2lit (ps, -ps->max_var);
    for (lit = int2lit (ps, 1); lit <= last; lit++)
      {
        stack = LIT2IMPLS (lit);
        eol = stack->start + stack->count;
        for (q = stack->start; q < eol; q++)
  	if ((other = *q) >= lit)
  	  fprintf (file, "%d %d 0\n", LIT2INT (lit), LIT2INT (other));
      }
  #endif
  
    {
      Lit **r;
      for (r = ps->als; r < ps->alshead; r++)
        fprintf (file, "%d 0\n", LIT2INT (*r));
    }
  
    fflush (file);
  
    if (ps->measurealltimeinlib)
      leave (ps);
  }
  
  void
  picosat_enter (PS * ps)
  {
    enter (ps);
  }
  
  void
  picosat_leave (PS * ps)
  {
    leave (ps);
  }
  
  void
  picosat_message (PS * ps, int vlevel, const char * fmt, ...)
  {
    va_list ap;
  
    if (vlevel > ps->verbosity)
      return;
  
    fputs (ps->prefix, ps->out);
    va_start (ap, fmt);
    vfprintf (ps->out, fmt, ap);
    va_end (ap);
    fputc ('\n', ps->out);
  }
  
  int
  picosat_changed (PS * ps)
  {
    int res;
  
    check_ready (ps);
    check_sat_state (ps);
  
    res = (ps->min_flipped <= ps->saved_max_var);
    assert (!res || ps->saved_flips != ps->flips);
  
    return res;
  }
  
  void
  picosat_reset_phases (PS * ps)
  {
    rebias (ps);
  }
  
  void
  picosat_reset_scores (PS * ps)
  {
    Rnk * r;
    ps->hhead = ps->heap + 1;
    for (r = ps->rnks + 1; r <= ps->rnks + ps->max_var; r++)
      {
        CLR (r);
        hpush (ps, r);
      }
  }
  
  void
  picosat_remove_learned (PS * ps, unsigned percentage)
  {
    enter (ps);
    reset_incremental_usage (ps);
    reduce (ps, percentage);
    leave (ps);
  }
  
  void
  picosat_set_global_default_phase (PS * ps, int phase)
  {
    check_ready (ps);
    ABORTIF (phase < 0, "API usage: 'picosat_set_global_default_phase' "
                        "with negative argument");
    ABORTIF (phase > 3, "API usage: 'picosat_set_global_default_phase' "
                        "with argument > 3");
    ps->defaultphase = phase;
  }
  
  void
  picosat_set_default_phase_lit (PS * ps, int int_lit, int phase)
  {
    unsigned newphase;
    Lit * lit;
    Var * v;
  
    check_ready (ps);
  
    lit = import_lit (ps, int_lit, 1);
    v = LIT2VAR (lit);
  
    if (phase)
      {
        newphase = (int_lit < 0) == (phase < 0);
        v->defphase = v->phase = newphase;
        v->usedefphase = v->assigned = 1;
      }
    else
      {
        v->usedefphase = v->assigned = 0;
      }
  }
  
  void
  picosat_set_more_important_lit (PS * ps, int int_lit)
  {
    Lit * lit;
    Var * v;
    Rnk * r;
  
    check_ready (ps);
  
    lit = import_lit (ps, int_lit, 1);
    v = LIT2VAR (lit);
    r = VAR2RNK (v);
  
    ABORTIF (r->lessimportant, "can not mark variable more and less important"); 
  
    if (r->moreimportant)
      return;
  
    r->moreimportant = 1;
  
    if (r->pos)
      hup (ps, r);
  }
  
  void
  picosat_set_less_important_lit (PS * ps, int int_lit)
  {
    Lit * lit;
    Var * v;
    Rnk * r;
  
    check_ready (ps);
  
    lit = import_lit (ps, int_lit, 1);
    v = LIT2VAR (lit);
    r = VAR2RNK (v);
  
    ABORTIF (r->moreimportant, "can not mark variable more and less important"); 
  
    if (r->lessimportant)
      return;
  
    r->lessimportant = 1;
  
    if (r->pos)
      hdown (ps, r);
  }
  
  #ifndef NADC
  
  unsigned 
  picosat_ado_conflicts (PS * ps)
  {
    check_ready (ps);
    return ps->adoconflicts;
  }
  
  void
  picosat_disable_ado (PS * ps)
  {
    check_ready (ps);
    assert (!ps->adodisabled);
    ps->adodisabled = 1;
  }
  
  void
  picosat_enable_ado (PS * ps)
  {
    check_ready (ps);
    assert (ps->adodisabled);
    ps->adodisabled = 0;
  }
  
  void
  picosat_set_ado_conflict_limit (PS * ps, unsigned newadoconflictlimit)
  {
    check_ready (ps);
    ps->adoconflictlimit = newadoconflictlimit;
  }
  
  #endif
  
  void
  picosat_simplify (PS * ps)
  {
    enter (ps);
    reset_incremental_usage (ps);
    simplify (ps, 1);
    leave (ps);
  }
  
  int
  picosat_haveados (void)
  {
  #ifndef NADC
    return 1;
  #else
    return 0;
  #endif
  }
  
  void
  picosat_save_original_clauses (PS * ps)
  {
    if (ps->saveorig) return;
    ABORTIF (ps->oadded, "API usage: 'picosat_save_original_clauses' too late");
    ps->saveorig = 1;
  }
  
  void picosat_set_interrupt (PicoSAT * ps,
                              void * external_state,
  			    int (*interrupted)(void * external_state)) 
  {
    ps->interrupt.state = external_state;
    ps->interrupt.function = interrupted;
  }
  
  int
  picosat_deref_partial (PS * ps, int int_lit) 
  {
    check_ready (ps);
    check_sat_state (ps);
    ABORTIF (!int_lit, "API usage: can not partial deref zero literal");
    ABORTIF (ps->mtcls, "API usage: deref partial after empty clause generated");
    ABORTIF (!ps->saveorig, "API usage: 'picosat_save_original_clauses' missing");
  
  #ifdef STATS
    ps->derefs++;
  #endif
  
    if (!ps->partial)
      minautarky (ps);
  
    return pderef (ps, int_lit);
  }
  
  #ifdef NDEBUG_TMP
  #define NDEBUG
  #endif
  
  #pragma clang diagnostic pop
  