/** Constructor. */
  public PTAModelChecker(Prism prism, ModulesFile modulesFile, PropertiesFile propertiesFile)
      throws PrismException {
    this.prism = prism;
    mainLog = prism.getMainLog();
    this.modulesFile = modulesFile;
    this.propertiesFile = propertiesFile;

    // Get combined constant values from model/properties
    constantValues = new Values();
    constantValues.addValues(modulesFile.getConstantValues());
    if (propertiesFile != null) constantValues.addValues(propertiesFile.getConstantValues());

    // Build a combined label list and expand any constants
    // (note labels in model are ignored (removed) during PTA translation so need to store here)
    labelList = new LabelList();
    for (int i = 0; i < modulesFile.getLabelList().size(); i++) {
      labelList.addLabel(
          modulesFile.getLabelList().getLabelNameIdent(i),
          modulesFile.getLabelList().getLabel(i).deepCopy());
    }
    for (int i = 0; i < propertiesFile.getLabelList().size(); i++) {
      labelList.addLabel(
          propertiesFile.getLabelList().getLabelNameIdent(i),
          propertiesFile.getLabelList().getLabel(i).deepCopy());
    }
    labelList = (LabelList) labelList.replaceConstants(constantValues);

    // Build mapping from all (original model) variables to non-clocks only
    int numVars = modulesFile.getNumVars();
    nonClockVarMap = new int[numVars];
    int count = 0;
    for (int i = 0; i < numVars; i++) {
      if (modulesFile.getVarType(i) instanceof TypeClock) {
        nonClockVarMap[i] = -1;
      } else {
        nonClockVarMap[i] = count++;
      }
    }
  }
  /**
   * Determine which locations in the PTA satisfy a (Boolean) expression. Note: This is rather
   * inefficiently at the moment. TODO: potentially use explicit.StateMC on dummy model eventually
   */
  private BitSet checkLocationExpression(Expression expr) throws PrismException {
    int i, n;
    BitSet res;

    // Labels - expand and recurse
    // (note: currently not used - these are expanded earlier)
    if (expr instanceof ExpressionLabel) {
      ExpressionLabel exprLabel = (ExpressionLabel) expr;
      if (exprLabel.getName().equals("deadlock"))
        throw new PrismException("The \"deadlock\" label is not yet supported for PTAs");
      if (exprLabel.getName().equals("init"))
        throw new PrismException("The \"init\" label is not yet supported for PTAs");
      i = labelList.getLabelIndex(exprLabel.getName());
      if (i == -1)
        throw new PrismException("Unknown label \"" + exprLabel.getName() + "\" in property");
      // Check recursively
      return checkLocationExpression(labelList.getLabel(i));

    }
    // Other expressions...
    else {
      List<Object> states;
      // Object[] state;
      states = pta.getLocationNameList();
      n = states.size();
      res = new BitSet(n);
      for (i = 0; i < n; i++) {
        // state = (Object[])states.get(i);
        State state = (State) states.get(i);
        if (expr.evaluateBoolean(state, nonClockVarMap)) {
          res.set(i);
        }
      }
    }

    return res;
  }