public Set<OWLClass> getRootUnsatisfiableClasses() throws ExplanationException { if(dirty) { rootUnsatClses.clear(); dirty = false; OWLReasonerFactory rf = new ProtegeOWLReasonerFactoryWrapper(modelManager.getOWLReasonerManager().getCurrentReasonerFactory()); RootDerivedReasoner gen = new StructuralRootDerivedReasoner(OWLManager.createOWLOntologyManager(), modelManager.getReasoner(), rf); rootUnsatClses.addAll(gen.getRootUnsatisfiableClasses()); } return Collections.unmodifiableSet(rootUnsatClses); }