@Override
 public String toTurtleString(Prefixes prefixes, Identifier mainNode) {
   StringBuffer buffer = new StringBuffer();
   if (mainNode == null) mainNode = AbstractExtendedOWLObject.getNextBlankNode();
   buffer.append(mainNode);
   buffer.append(" ");
   buffer.append(Vocabulary.RDF_TYPE.toString(prefixes));
   buffer.append(" ");
   buffer.append(Vocabulary.OWL_RESTRICTION.toString(prefixes));
   buffer.append(" . ");
   buffer.append(LB);
   buffer.append(mainNode);
   buffer.append(" ");
   buffer.append(Vocabulary.OWL_ON_PROPERTY.toString(prefixes));
   buffer.append(" ");
   if (m_ope instanceof Atomic) {
     buffer.append(m_ope.toString(prefixes));
     buffer.append(" . ");
     buffer.append(LB);
   } else {
     AnonymousIndividual opebnode = AbstractExtendedOWLObject.getNextBlankNode();
     buffer.append(opebnode);
     buffer.append(" . ");
     buffer.append(LB);
     buffer.append(m_ope.toTurtleString(prefixes, opebnode));
   }
   buffer.append(mainNode);
   buffer.append(" ");
   buffer.append(Vocabulary.OWL_ALL_VALUES_FROM.toString(prefixes));
   buffer.append(" ");
   if (m_classExpression instanceof Atomic) {
     buffer.append(m_classExpression.toString(prefixes));
     buffer.append(" . ");
     buffer.append(LB);
   } else {
     AnonymousIndividual cebnode = AbstractExtendedOWLObject.getNextBlankNode();
     buffer.append(cebnode);
     buffer.append(" . ");
     buffer.append(LB);
     buffer.append(m_classExpression.toTurtleString(prefixes, cebnode));
   }
   return buffer.toString();
 }
 @Override
 public String toString(Prefixes prefixes) {
   StringBuffer buffer = new StringBuffer();
   buffer.append("ObjectAllValuesFrom(");
   buffer.append(m_ope.toString(prefixes));
   buffer.append(" ");
   buffer.append(m_classExpression.toString(prefixes));
   buffer.append(")");
   return buffer.toString();
 }
 public ExtendedOWLObject getBoundVersion(Map<Variable, ? extends Atomic> variablesToBindings) {
   return create(
       (ObjectPropertyExpression) m_ope.getBoundVersion(variablesToBindings),
       (ClassExpression) m_classExpression.getBoundVersion(variablesToBindings));
 }
 public Set<Variable> getVariablesInSignature(VarType varType) {
   Set<Variable> variables = new HashSet<Variable>();
   variables.addAll(m_ope.getVariablesInSignature(varType));
   variables.addAll(m_classExpression.getVariablesInSignature(varType));
   return variables;
 }