@Override
 public void reset() {
   super.reset();
   m_phi.reset();
   m_mons = new LinkedList<ValuePair>();
   m_variableResolver = new HashMap<String, String>();
 }
 @Override
 public void setValue(Atom a, Atom v) {
   m_phi.setValue(a, v);
   m_variableResolver.put(a.toString(), v.toString());
 }