private void handleAxiomRemoved(OWLAxiom axiom) {
Set<OWLEntity> sig=new HashSet<OWLEntity>();
Set<OWLAnonymousIndividual> anons=new HashSet<OWLAnonymousIndividual>();
OWLEntityCollector entityCollector = new OWLEntityCollector(sig, anons);
OWLNamedObjectReferenceRemover referenceRemover = getReferenceRemover();
axiom.accept(entityCollector);
for (OWLEntity object : sig) {
referenceRemover.setAxiom(axiom);
object.accept(referenceRemover);