xref: /dports/math/stp/stp-2.3.3/lib/AbsRefineCounterExample/CounterExample.cpp

/********************************************************************
 * AUTHORS: Vijay Ganesh
 *
 * BEGIN DATE: November, 2005
 *
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 "stp/AbsRefineCounterExample/AbsRefine_CounterExample.h"
#include "stp/Printer/printers.h"
#include "stp/ToSat/AIG/ToSATAIG.h"

const bool debug_counterexample = false;

namespace stp
{
using std::cout;

/*FUNCTION: constructs counterexample from MINISAT counterexample
 * step1 : iterate through MINISAT counterexample and assemble the
 * bits for each AST term. Store it in a map from ASTNode to vector
 * of bools (bits).
 *
 * step2: Iterate over the map from ASTNodes->Vector-of-Bools and
 * populate the CounterExampleMap data structure (ASTNode -> BVConst)
 */
void AbsRefine_CounterExample::ConstructCounterExample(
    SATSolver& newS, ToSATBase::ASTNodeToSATVar& satVarToSymbol)
{
  if (!newS.okay())
    return;
  if (!bm->UserFlags.construct_counterexample_flag)
    return;

  assert(CounterExampleMap.size() == 0);

  CopySolverMap_To_CounterExample();

  for (ToSATBase::ASTNodeToSATVar::const_iterator it = satVarToSymbol.begin();
       it != satVarToSymbol.end(); it++)
  {
    const ASTNode& symbol = it->first;
    const vector<unsigned>& v = it->second;

    const unsigned int symbolWidth = symbol.GetValueWidth();
    assert(symbol.GetKind() == SYMBOL);
    vector<bool> bitVector_array(symbolWidth, false);

    for (size_t index = 0; index < v.size(); index++)
    {
      const unsigned sat_variable_index = v[index];

      if (sat_variable_index == ~((unsigned)0)) // not sent to the sat solver.
        continue;

      if (newS.modelValue(sat_variable_index) == newS.undef_literal())
        continue;

      // assemble the counterexample here
      if (symbol.GetType() == BITVECTOR_TYPE)
      {
        // Collect the bits of 'symbol' and store in v. Store
        // in reverse order.
        bitVector_array[(symbolWidth - 1) - index] =
            (newS.modelValue(sat_variable_index) == newS.true_literal());
      }
      else
      {
        assert(symbol.GetType() == BOOLEAN_TYPE);
        if (newS.modelValue(sat_variable_index) == newS.true_literal())
          CounterExampleMap[symbol] = ASTTrue;
        else if (newS.modelValue(sat_variable_index) == newS.false_literal())
          CounterExampleMap[symbol] = ASTFalse;
        else
          FatalError("never heres.");
      }
    }

    if (symbol.GetType() == BITVECTOR_TYPE)
    {
      CounterExampleMap[symbol] =
          BoolVectoBVConst(&bitVector_array, symbol.GetValueWidth());
    }
  }

  for (ArrayTransformer::ArrType::const_iterator
           it = ArrayTransform->arrayToIndexToRead.begin(),
           itend = ArrayTransform->arrayToIndexToRead.end();
       it != itend; it++)
  {
    const ASTNode& array = it->first;
    const std::map<ASTNode, ArrayTransformer::ArrayRead>& mapper = it->second;

    for (std::map<ASTNode, ArrayTransformer::ArrayRead>::const_iterator
             it2 = mapper.begin(),
             it2end = mapper.end();
         it2 != it2end; it2++)
    {
      const ASTNode& index = it2->first;
      const ASTNode& value_ite = it2->second.ite;

      // convert it to a constant array-read and store it in the
      // counter-example. First convert the index into a constant. then
      // construct the appropriate array-read and store it in the
      // counterexample
      ASTNode arrayread_index = TermToConstTermUsingModel(index, false);
      ASTNode key =
          bm->CreateTerm(READ, array.GetValueWidth(), array, arrayread_index);

      // Get the ITE corresponding to the array-read and convert it
      // to a constant against the model
      ASTNode value = TermToConstTermUsingModel(value_ite);
      // save the result in the counter_example
      if (!simp->InsideSubstitutionMap(key))
        CounterExampleMap[key] = value;
    }
  }
}

// FUNCTION: accepts a non-constant term, and returns the
// corresponding constant term with respect to a model.
//
// term READ(A,i) is treated as follows:
//
// 1. If (the boolean variable 'ArrayReadFlag' is true && ArrayRead
// 1. has value in counterexample), then return the value of the
// 1. arrayread.
//
// 2. If (the boolean variable 'ArrayReadFlag' is true && ArrayRead
// 2. doesn't have value in counterexample), then return the
// 2. arrayread itself (normalized such that arrayread has a constant
// 2. index)
//
// 3. If (the boolean variable 'ArrayReadFlag' is false) && ArrayRead
// 3. has a value in the counterexample then return the value of the
// 3. arrayread.
//
// 4. If (the boolean variable 'ArrayReadFlag' is false) && ArrayRead
// 4. doesn't have a value in the counterexample then return 0 as the
// 4. value of the arrayread.
ASTNode AbsRefine_CounterExample::TermToConstTermUsingModel(const ASTNode& term,
                                                            bool ArrayReadFlag)
{
  if (term.GetKind() == BVCONST)
    return term;

  const Kind k = term.GetKind();

  assert(is_Term_kind(k));
  assert(k != WRITE);
  assert(BOOLEAN_TYPE != term.GetType());

  ASTNodeMap::const_iterator it1;
  if ((it1 = CounterExampleMap.find(term)) != CounterExampleMap.end())
  {
    const ASTNode& val = it1->second;
    if (BVCONST != val.GetKind())
    {
      // CounterExampleMap has two maps rolled into
      // one. SubstitutionMap and SolverMap.
      //
      // recursion is fine here. There are two maps that are checked
      // here. One is the substitutionmap. We garuntee that the value
      // of a key in the substitutionmap is always a constant.
      //
      // in the SolverMap we garuntee that "term" does not occur in
      // the value part of the map
      if (term == val)
      {
        FatalError("TermToConstTermUsingModel: "
                   "The input term is stored as-is "
                   "in the CounterExample: Not ok: ",
                   term);
      }
      return TermToConstTermUsingModel(val, ArrayReadFlag);
    }
    else
    {
      return val;
    }
  }

  ASTNode output;
  switch (k)
  {
    case BVCONST:
      output = term;
      break;
    case SYMBOL:
    {
      if (term.GetType() == ARRAY_TYPE)
      {
        return term;
      }

      // Has been simplified out. Can take any value.
      output = bm->CreateZeroConst(term.GetValueWidth());
      break;
    }
    case READ:
    {
      ASTNode arrName = term[0];
      ASTNode index = term[1];
      if (0 == arrName.GetIndexWidth())
      {
        FatalError("TermToConstTermUsingModel: "
                   "array has 0 index width: ",
                   arrName);
      }

      if (WRITE == arrName.GetKind()) // READ over a WRITE
      {
        ASTNode wrtterm = Expand_ReadOverWrite_UsingModel(term, ArrayReadFlag);
        if (wrtterm == term)
        {
          FatalError("TermToConstTermUsingModel: "
                     "Read_Over_Write term must be expanded "
                     "into an ITE",
                     term);
        }
        ASTNode rtterm = TermToConstTermUsingModel(wrtterm, ArrayReadFlag);
        assert(ArrayReadFlag || (BVCONST == rtterm.GetKind()));
        return rtterm;
      }
      else if (ITE == arrName.GetKind()) // READ over an ITE
      {
        // The "then" and "else" branch are arrays.
        ASTNode indexVal = TermToConstTermUsingModel(index, ArrayReadFlag);

        ASTNode condcompute =
            ComputeFormulaUsingModel(arrName[0]); // Get the truth value.
        unsigned int wid = arrName.GetValueWidth();
        if (ASTTrue == condcompute)
        {
          const ASTNode& result = TermToConstTermUsingModel(
              bm->CreateTerm(READ, wid, arrName[1], indexVal), ArrayReadFlag);
          assert(ArrayReadFlag || (BVCONST == result.GetKind()));
          return result;
        }
        else if (ASTFalse == condcompute)
        {
          const ASTNode& result = TermToConstTermUsingModel(
              bm->CreateTerm(READ, wid, arrName[2], indexVal), ArrayReadFlag);
          assert(ArrayReadFlag || (BVCONST == result.GetKind()));
          return result;
        }
        else
        {
          FatalError(" TermToConstTermUsingModel: termITE: "
                     "cannot compute ITE conditional against model: ",
                     term);
        }
      }

      ASTNode modelentry;
      if (CounterExampleMap.find(index) != CounterExampleMap.end())
      {
        // index has a const value in the CounterExampleMap
        // ASTNode indexVal = CounterExampleMap[index];
        ASTNode indexVal =
            TermToConstTermUsingModel(CounterExampleMap[index], ArrayReadFlag);
        modelentry =
            bm->CreateTerm(READ, arrName.GetValueWidth(), arrName, indexVal);
      }
      else
      {
        // index does not have a const value in the
        // CounterExampleMap. compute it.
        ASTNode indexconstval = TermToConstTermUsingModel(index, ArrayReadFlag);
        // update model with value of the index
        // CounterExampleMap[index] = indexconstval;
        modelentry = bm->CreateTerm(READ, arrName.GetValueWidth(), arrName,
                                    indexconstval);
      }
      // modelentry is now an arrayread over a constant index
      BVTypeCheck(modelentry);

      // if a value exists in the CounterExampleMap then return it
      if (CounterExampleMap.find(modelentry) != CounterExampleMap.end())
      {
        output = TermToConstTermUsingModel(CounterExampleMap[modelentry],
                                           ArrayReadFlag);
      }
      else if (ArrayReadFlag)
      {
        // return the array read over a constantindex
        output = modelentry;
      }
      else
      {
        // Has been simplified out. Can take any value.
        output = bm->CreateMaxConst(modelentry.GetValueWidth());
      }
      break;
    }
    case ITE:
    {
      ASTNode condcompute = ComputeFormulaUsingModel(term[0]);
      if (ASTTrue == condcompute)
      {
        output = TermToConstTermUsingModel(term[1], ArrayReadFlag);
      }
      else if (ASTFalse == condcompute)
      {
        output = TermToConstTermUsingModel(term[2], ArrayReadFlag);
      }
      else
      {
        FatalError(" TermToConstTermUsingModel: termITE: cannot "
                   "compute ITE conditional against model: ",
                   term);
      }
      break;
    }
    default:
    {
      const ASTVec& c = term.GetChildren();
      ASTVec o;
      o.reserve(c.size());
      for (ASTVec::const_iterator it = c.begin(), itend = c.end(); it != itend;
           it++)
      {
        ASTNode ff = TermToConstTermUsingModel(*it, ArrayReadFlag);
        o.push_back(ff);
      }

      output = NonMemberBVConstEvaluator(bm, k, o, term.GetValueWidth());
      break;
    }
  }

  assert(ArrayReadFlag || (BVCONST == output.GetKind()));

  // when this flag is false, we should compute the arrayread to a
  // constant. this constant is stored in the counter_example
  // datastructure
  // if (!ArrayReadFlag)
  {
    CounterExampleMap[term] = output;
  }

  // cerr << "Output to TermToConstTermUsingModel: " << output << endl;
  return output;
}

// Expands read-over-write by evaluating (readIndex=writeIndex) for
// every writeindex until, either it evaluates to TRUE or all
//(readIndex=writeIndex) evaluate to FALSE
ASTNode
AbsRefine_CounterExample::Expand_ReadOverWrite_UsingModel(const ASTNode& term,
                                                          bool arrayread_flag)
{
  if (READ != term.GetKind() || WRITE != term[0].GetKind())
  {
    FatalError("RemovesWrites: Input must be a READ over a WRITE", term);
  }

  ASTNode output;
  ASTNodeMap::iterator it1;
  if ((it1 = CounterExampleMap.find(term)) != CounterExampleMap.end())
  {
    const ASTNode& val = it1->second;
    if (BVCONST != val.GetKind())
    {
      // recursion is fine here. There are two maps that are checked
      // here. One is the substitutionmap. We garuntee that the value
      // of a key in the substitutionmap is always a constant.
      if (term == val)
      {
        FatalError("TermToConstTermUsingModel: The input term is "
                   "stored as-is "
                   "in the CounterExample: Not ok: ",
                   term);
      }
      return TermToConstTermUsingModel(val, arrayread_flag);
    }
    else
    {
      return val;
    }
  }

  ASTNode newRead = term;
  const ASTNode readIndex = TermToConstTermUsingModel(newRead[1], false);
  // iteratively expand read-over-write, and evaluate against the
  // model at every iteration
  ASTNode write = newRead[0];
  do
  {
    ASTNode writeIndex = TermToConstTermUsingModel(write[1], false);

    if (writeIndex == readIndex)
    {
      // found the write-value. return it
      output = TermToConstTermUsingModel(write[2], false);
      CounterExampleMap[term] = output;
      return output;
    }

    write = write[0];
  } while (WRITE == write.GetKind());

  const unsigned int width = term.GetValueWidth();
  newRead = bm->CreateTerm(READ, width, write, readIndex);
  output = TermToConstTermUsingModel(newRead, arrayread_flag);

  // memoize
  CounterExampleMap[term] = output;
  return output;
} // Expand_ReadOverWrite_UsingModel()

/* FUNCTION: accepts a non-constant formula, and checks if the
 * formula is ASTTrue or ASTFalse w.r.t to a model
 */
ASTNode AbsRefine_CounterExample::ComputeFormulaUsingModel(const ASTNode& form)
{
  const Kind k = form.GetKind();
  if (!(is_Form_kind(k) && BOOLEAN_TYPE == form.GetType()))
  {
    FatalError(" ComputeConstFormUsingModel: "
               "The input is a non-formula: ",
               form);
  }

  // cerr << "Input to ComputeFormulaUsingModel:" << form << endl;
  ASTNodeMap::const_iterator it1;
  if ((it1 = ComputeFormulaMap.find(form)) != ComputeFormulaMap.end())
  {
    const ASTNode& res = it1->second;
    if (ASTTrue == res || ASTFalse == res)
    {
      return res;
    }
    else
    {
      FatalError("ComputeFormulaUsingModel: "
                 "The value of a formula must be TRUE or FALSE:",
                 form);
    }
  }

  ASTNode output = ASTUndefined;
  switch (k)
  {
    case TRUE:
    case FALSE:
      output = form;
      break;
    case SYMBOL:
      if (BOOLEAN_TYPE != form.GetType())
        FatalError(" ComputeFormulaUsingModel: "
                   "Non-Boolean variables are not formulas",
                   form);
      if (CounterExampleMap.find(form) != CounterExampleMap.end())
      {
        ASTNode counterexample_val = CounterExampleMap[form];
        if (!bm->VarSeenInTerm(form, counterexample_val))
        {
          output = ComputeFormulaUsingModel(counterexample_val);
        }
        else
        {
          output = counterexample_val;
        }
      }
      else
      {
        // Has been simplified out. Can take any value.
        output = ASTFalse;
      }
      break;
    case BOOLEXTRACT:
    {
      ASTNode t0 = TermToConstTermUsingModel(form[0]);
      output = simp->BVConstEvaluator(bm->CreateNode(BOOLEXTRACT, t0, form[1]));
      break;
    }
    case EQ:
    case BVLT:
    case BVLE:
    case BVGT:
    case BVGE:
    case BVSLT:
    case BVSLE:
    case BVSGT:
    case BVSGE:
    {
      ASTVec children;
      children.reserve(form.Degree());

      for (ASTVec::const_iterator it = form.begin(), itend = form.end();
           it != itend; it++)
      {
        children.push_back(TermToConstTermUsingModel(*it, false));
      }

      output = NonMemberBVConstEvaluator(bm, k, children, form.GetValueWidth());
    }
    break;

    case NAND:
    case NOR:
    case NOT:
    case AND:
    case XOR:
    case IFF:
    case IMPLIES:
    case OR:
    {
      ASTVec children;
      children.reserve(form.Degree());

      for (ASTVec::const_iterator it = form.begin(), itend = form.end();
           it != itend; it++)
      {
        children.push_back(ComputeFormulaUsingModel(*it));
      }

      output = NonMemberBVConstEvaluator(bm, k, children, form.GetValueWidth());
    }
    break;

    case ITE:
    {
      ASTNode t0 = ComputeFormulaUsingModel(form[0]);
      if (ASTTrue == t0)
        output = ComputeFormulaUsingModel(form[1]);
      else if (ASTFalse == t0)
        output = ComputeFormulaUsingModel(form[2]);
      else
        FatalError("ComputeFormulaUsingModel: ITE: "
                   "something is wrong with the formula: ",
                   form);
    }
    break;
    case PARAMBOOL:
      output = bm->NewParameterized_BooleanVar(form[0], form[1]);
      output = ComputeFormulaUsingModel(output);
      break;
    default:
      cerr << _kind_names[k];
      FatalError(" ComputeFormulaUsingModel: "
                 "the kind has not been implemented",
                 ASTUndefined);
      break;
  }

  assert(ASTUndefined != output);
  assert(output.isConstant());
  ComputeFormulaMap[form] = output;
  return output;
}

void AbsRefine_CounterExample::CheckCounterExample(bool t)
{
  // input is valid, no counterexample to check
  if (bm->ValidFlag)
    return;

  // t is true if SAT solver generated a counterexample, else it is false
  if (!t)
    FatalError("CheckCounterExample: "
               "No CounterExample to check",
               ASTUndefined);
  const ASTVec c = bm->GetAsserts();

  if (bm->UserFlags.stats_flag)
    printf("checking counterexample\n");

  for (ASTVec::const_iterator it = c.begin(), itend = c.end(); it != itend;
       it++)
  {
    if (debug_counterexample)
      cerr << "checking" << *it;

    if (ASTFalse == ComputeFormulaUsingModel(*it))
      FatalError("CheckCounterExample:counterexample bogus:"
                 "assert evaluates to FALSE under counterexample: "
                 "NOT OK",
                 *it);
  }

  // The smtlib ones don't have a query defined.
  if ((bm->GetQuery() != ASTUndefined) &&
      ASTTrue == ComputeFormulaUsingModel(bm->GetQuery()))
    FatalError("CheckCounterExample:counterexample bogus:"
               "query evaluates to TRUE under counterexample: "
               "NOT OK",
               bm->GetQuery());
}

/* FUNCTION: queries the value of expr given the current counterexample.
 */
ASTNode AbsRefine_CounterExample::GetCounterExample(const ASTNode& expr)
{
  // input is valid, no counterexample to get
  if (bm->ValidFlag)
    return ASTUndefined;

  if (BOOLEAN_TYPE == expr.GetType())
  {
    return ComputeFormulaUsingModel(expr);
  }

  return TermToConstTermUsingModel(expr, false);
}

// FUNCTION: queries the counterexample, and returns the number of array
// locations for e
vector<std::pair<ASTNode, ASTNode>>
AbsRefine_CounterExample::GetCounterExampleArray(bool t, const ASTNode& e)
{
  vector<std::pair<ASTNode, ASTNode>> entries;

  // input is valid, no counterexample to print
  if (bm->ValidFlag)
  {
    return entries;
  }

  // t is true if SAT solver generated a counterexample, else it is
  // false
  if (!t)
  {
    return entries;
  }

  // Take a copy of the counterexample map, 'cause TermToConstTermUsingModel
  // changes it. Which breaks the iterator otherwise.
  const ASTNodeMap c(CounterExampleMap);

  ASTNodeMap::const_iterator it = c.begin();
  ASTNodeMap::const_iterator itend = c.end();
  for (; it != itend; it++)
  {
    const ASTNode& f = it->first;
    const ASTNode& se = it->second;

    if (ARRAY_TYPE == se.GetType())
    {
      FatalError("TermToConstTermUsingModel: "
                 "entry in counterexample is an arraytype. bogus:",
                 se);
    }

    // skip over introduced variables
    if (f.GetKind() == SYMBOL && (bm->FoundIntroducedSymbolSet(f)))
    {
      continue;
    }
    if (f.GetKind() == READ && f[0] == e && f[0].GetKind() == SYMBOL &&
        f[1].GetKind() == BVCONST)
    {
      ASTNode rhs;
      if (BITVECTOR_TYPE == se.GetType())
      {
        rhs = TermToConstTermUsingModel(se, false);
      }
      else
      {
        rhs = ComputeFormulaUsingModel(se);
      }
      assert(rhs.isConstant());
      entries.push_back(std::make_pair(f[1], rhs));
    }
  }

  return entries;
}

// TODO printing of expressions.
// TODO move to printer file.
void AbsRefine_CounterExample::PrintSMTLIB2(std::ostream& os, const ASTNode& n)
{
  if (n.GetKind() == SYMBOL)
  {
    os << "( ";

    os << "|";
    n.nodeprint(os);
    os << "| ";

    if (n.GetType() == stp::BITVECTOR_TYPE)
      printer::outputBitVecSMTLIB2(TermToConstTermUsingModel(n, false), os);
    else
    {
      if (ASTTrue == ComputeFormulaUsingModel(n))
        os << "true";
      else
        os << "false";
    }
    os << " )";
  }
}

void AbsRefine_CounterExample::PrintCounterExampleSMTLIB2(std::ostream& os)
{
  // Take a copy of the counterexample map, 'cause TermToConstTermUsingModel
  // changes it. Which breaks the iterator otherwise.
  const ASTNodeMap c(CounterExampleMap);

  ASTNodeMap::const_iterator it = c.begin();
  ASTNodeMap::const_iterator itend = c.end();
  for (; it != itend; it++)
  {
    const ASTNode& f = it->first;
    const ASTNode& se = it->second;

    if (ARRAY_TYPE == se.GetType())
    {
      FatalError("PrintCounterExampleSMTLIB2: "
                 "entry in counterexample is an arraytype. bogus:",
                 se);
    }

    // skip over introduced variables
    if (f.GetKind() == SYMBOL && (bm->FoundIntroducedSymbolSet(f)))
    {
      continue;
    }

    if (f.GetKind() == SYMBOL)
    {
      os << "( define-fun ";
      os << "|";
      f.nodeprint(os);
      os << "|";

      if (f.GetType() == stp::BITVECTOR_TYPE)
      {
        os << " () (";
        os << "_ BitVec " << f.GetValueWidth() << ")";
        printer::outputBitVecSMTLIB2(TermToConstTermUsingModel(se, false), os);
      }
      else if (f.GetType() == stp::BOOLEAN_TYPE)
      {
        os << " () Bool ";
      }
      else
      {
        FatalError("Wrong Type");
      }

      os << " )" << std::endl;
    }

    //TODO completely the wrong format.
    if ((f.GetKind() == READ && f[0].GetKind() == SYMBOL &&
         f[1].GetKind() == BVCONST))
    {

      os << "( define-fun ";

      os << "|";
      f[0].nodeprint(os);
      os << "| ";

      os << " (";
      os << "_ BitVec " << f[0].GetIndexWidth() << ")";

      os << " (";
      os << "_ BitVec " << f[0].GetValueWidth() << ")";

      printer::outputBitVecSMTLIB2(TermToConstTermUsingModel(f[1], false), os);

      printer::outputBitVecSMTLIB2(TermToConstTermUsingModel(se, false), os);
      os << " )" << endl;
    }
  }
  os.flush();
}

// FUNCTION: prints a counterexample for INVALID inputs.  iterate
// through the CounterExampleMap data structure and print it to
// stdout
void AbsRefine_CounterExample::PrintCounterExample(bool t, std::ostream& os)
{
  // input is valid, no counterexample to print
  if (bm->ValidFlag)
  {
    return;
  }

  // if this option is true then print the way dawson wants using a
  // different printer. do not use this printer.
  if (bm->UserFlags.print_arrayval_declaredorder_flag)
  {
    return;
  }

  // t is true if SAT solver generated a counterexample, else it is
  // false
  if (!t)
  {
    os << "PrintCounterExample: No CounterExample to print: " << endl;
    return;
  }

  bm->PLPrintNodeSet.clear();
  bm->NodeLetVarMap.clear();
  bm->NodeLetVarVec.clear();
  bm->NodeLetVarMap1.clear();

  // Take a copy of the counterexample map, 'cause TermToConstTermUsingModel
  // changes it. Which breaks the iterator otherwise.
  const ASTNodeMap c(CounterExampleMap);

  ASTNodeMap::const_iterator it = c.begin();
  ASTNodeMap::const_iterator itend = c.end();
  for (; it != itend; it++)
  {
    const ASTNode& f = it->first;
    const ASTNode& se = it->second;

    if (ARRAY_TYPE == se.GetType())
    {
      FatalError("TermToConstTermUsingModel: "
                 "entry in counterexample is an arraytype. bogus:",
                 se);
    }

    // skip over introduced variables
    if (f.GetKind() == SYMBOL && (bm->FoundIntroducedSymbolSet(f)))
    {
      continue;
    }
    if (f.GetKind() == SYMBOL ||
        (f.GetKind() == READ && f[0].GetKind() == SYMBOL &&
         f[1].GetKind() == BVCONST))
    {

      os << "ASSERT( ";

      printer::PL_Print1(os, f, 0, false, bm);
      if (BOOLEAN_TYPE == f.GetType())
      {
        os << "<=>";
      }
      else
      {
        os << " = ";
      }

      ASTNode rhs;
      if (BITVECTOR_TYPE == se.GetType())
      {
        rhs = TermToConstTermUsingModel(se, false);
      }
      else
      {
        rhs = ComputeFormulaUsingModel(se);
      }
      assert(rhs.isConstant());
      printer::PL_Print1(os, rhs, 0, false, bm);

      os << " );" << endl;
    }
  }
}

/* iterate through the CounterExampleMap data structure and print it
 * to stdout. this function prints only the declared array variables
 * IN the ORDER in which they were declared. It also assumes that
 * the variables are of the form 'varname_number'. otherwise it will
 * not print anything. This function was specifically written for
 * Dawson Engler's group (bug finding research group at Stanford)
 */
void AbsRefine_CounterExample::PrintCounterExample_InOrder(bool t)
{
  // global command-line option to print counterexample. we do not
  // want both counterexample printers to print at the sametime.
  // FIXME: This should always print the counterexample.  If you want
  // to turn it off, check the switch at the point of call.
  if (bm->UserFlags.print_counterexample_flag)
    return;

  // input is valid, no counterexample to print
  if (bm->ValidFlag)
    return;

  // print if the commandline option is '-q'. allows printing the
  // counterexample in order.
  if (!bm->UserFlags.print_arrayval_declaredorder_flag)
    return;

  // t is true if SAT solver generated a counterexample, else it is
  // false
  if (!t)
  {
    cerr << "PrintCounterExample: No CounterExample to print: " << endl;
    return;
  }

  // vector to store the integer values
  vector<int> out_int;
  cout << "% ";
  for (ASTVec::iterator it = bm->ListOfDeclaredVars.begin(),
                        itend = bm->ListOfDeclaredVars.end();
       it != itend; it++)
  {
    if (ARRAY_TYPE == it->GetType())
    {
      // get the name of the variable
      const char* c = it->GetName();
      std::string ss(c);
      if (!(0 == strncmp(ss.c_str(), "ini_", 4)))
        continue;
      reverse(ss.begin(), ss.end());

      // cout << "debugging: " << ss;
      size_t pos = ss.find('_', 0);
      if (!((0 < pos) && (pos < ss.size())))
        continue;

      // get the associated length
      std::string sss = ss.substr(0, pos);
      reverse(sss.begin(), sss.end());
      int n = atoi(sss.c_str());

      it->PL_Print(cout, bm, 2);
      for (int j = 0; j < n; j++)
      {
        ASTNode index = bm->CreateBVConst(it->GetIndexWidth(), j);
        ASTNode readexpr =
            bm->CreateTerm(READ, it->GetValueWidth(), *it, index);
        ASTNode val = GetCounterExample(readexpr);
        // cout << "ASSERT( ";
        // cout << " = ";
        out_int.push_back(val.GetUnsignedConst());
        // cout << "\n";
      }
    }
  }
  cout << endl;
  for (unsigned int jj = 0; jj < out_int.size(); jj++)
    cout << out_int[jj] << endl;
  cout << endl;
}

// Prints Satisfying assignment directly, for debugging.
void AbsRefine_CounterExample::PrintSATModel(SATSolver& newS,
                                             ToSATBase::ASTNodeToSATVar& m)
{
  if (!newS.okay())
    FatalError("PrintSATModel: NO COUNTEREXAMPLE TO PRINT", ASTUndefined);
  if (!(bm->UserFlags.stats_flag && bm->UserFlags.print_nodes_flag))
    return;

  cout << "Satisfying assignment: " << endl;
  for (ToSATBase::ASTNodeToSATVar::const_iterator it = m.begin(); it != m.end();
       it++)
  {
    ASTNode symbol = it->first;
    vector<unsigned> v = it->second;

    for (size_t i = 0; i < v.size(); i++)
    {
      if (v[i] == ~((unsigned)0)) // nb. special value.
        continue;

      if (newS.modelValue(v[i]) == newS.true_literal())
      {
        it->first.nodeprint(cout);
        cout << " {" << i << "}" << endl;
      }
      else if (newS.modelValue(v[i]) == newS.false_literal())
      {
        cout << "NOT ";
        it->first.nodeprint(cout);
        cout << " {" << i << "}" << endl;
      }
    }
  }
}

// FUNCTION: this function accepts a boolvector and returns a BVConst
ASTNode AbsRefine_CounterExample::BoolVectoBVConst(const vector<bool>* w,
                                                   const unsigned int l)
{
  assert(l == (unsigned)w->size());

  CBV cc = CONSTANTBV::BitVector_Create(l, true);
  for (unsigned int jj = 0; jj < l; jj++)
  {
    if ((*w)[jj] == true)
      CONSTANTBV::BitVector_Bit_On(cc, l - 1 - jj);
  }

  return bm->CreateBVConst(cc, l);
}

void AbsRefine_CounterExample::CopySolverMap_To_CounterExample(void)
{

  if (!simp->Return_SolverMap()->empty())
  {
    CounterExampleMap.insert(simp->Return_SolverMap()->begin(),
                             simp->Return_SolverMap()->end());
  }
}

SOLVER_RETURN_TYPE
AbsRefine_CounterExample::CallSAT_ResultCheck(SATSolver& SatSolver,
                                              const ASTNode& modified_input,
                                              const ASTNode& original_input,
                                              ToSATBase* tosat, bool refinement)
{
  bool sat = tosat->CallSAT(SatSolver, modified_input, refinement);

  if (bm->soft_timeout_expired)
    return SOLVER_TIMEOUT;

  if (!sat)
  {
    return SOLVER_VALID;
  }
  else if (SatSolver.okay())
  {
    if (!bm->UserFlags.construct_counterexample_flag)
      return SOLVER_INVALID;

    bm->GetRunTimes()->start(RunTimes::CounterExampleGeneration);
    CounterExampleMap.clear();
    ComputeFormulaMap.clear();

    ToSAT::ASTNodeToSATVar satVarToSymbol = tosat->SATVar_to_SymbolIndexMap();
    ConstructCounterExample(SatSolver, satVarToSymbol);
    if (bm->UserFlags.stats_flag && bm->UserFlags.print_nodes_flag)
    {
      ToSAT::ASTNodeToSATVar m = tosat->SATVar_to_SymbolIndexMap();
      PrintSATModel(SatSolver, m);
    }
    // check if the counterexample is good or not
    ASTNode orig_result = ComputeFormulaUsingModel(original_input);
    if (!(ASTTrue == orig_result || ASTFalse == orig_result))
      FatalError("TopLevelSat: Original input must compute to "
                 "true or false against model");
    bm->GetRunTimes()->stop(RunTimes::CounterExampleGeneration);

    // if the counterexample is indeed a good one, then return
    // invalid
    if (ASTTrue == orig_result)
    {
      if (bm->UserFlags.check_counterexample_flag)
      {
        CheckCounterExample(SatSolver.okay());
      }

      if (bm->UserFlags.stats_flag || bm->UserFlags.print_counterexample_flag)
      {
        PrintCounterExample(SatSolver.okay());
        PrintCounterExample_InOrder(SatSolver.okay());
      }
      return SOLVER_INVALID;
    }
    // counterexample is bogus: flag it
    else
    {
      if (bm->UserFlags.stats_flag && bm->UserFlags.print_nodes_flag)
      {
        cout << "Supposedly bogus one: \n";
        PrintCounterExample(true);
      }

      return SOLVER_UNDECIDED;
    }
  }
  else
  {
    // Control should never reach here
    // PrintOutput(true);
    return SOLVER_ERROR;
  }
}
}