'OWLKnowledgeExplorerReasoner - getObjectLabel always ends in error Unreachable situation

I am trying to access information about completion graph, but everytime it ends with error uk.ac.manchester.cs.jfact.helpers.UnreachableSituationException: Unreachable situation! when I call getObjectLabel(rootNode, false/true). I was trying it on every class expression from the ontology but always ended up with the error message.

Set<OWLClassExpression> types = classSet2classExpSet(hybridSolver.ontology.classesInSignature().collect(toSet()));
for (OWLClassExpression e : types) {
    OWLKnowledgeExplorerReasoner.RootNode rootNode = loader.getReasoner().getRoot(e);
    System.out.println(loader.getReasoner().getObjectLabel(rootNode, false)); //problem UnreachableSituation !!
    Node<OWLObjectProperty> propertyNode = (Node<OWLObjectProperty>) loader.getReasoner().getObjectNeighbours(rootNode, false);
    for (OWLObjectProperty p : propertyNode.getEntities()) {
                Collection<OWLKnowledgeExplorerReasoner.RootNode> rootNodes = loader.getReasoner().getObjectNeighbours(rootNode, p);
                ...
    }
}

Other method getObjectNeighbours(rootNote, false) works fine.

Can somebody help? Is there any way to access completion graph with OWLAPI? Why it might end with this error?

ontologyowl-apireasoning


Solution 1:[1]

The labels found for the nodes in question are not named class expressions (e.g., they are AND nodes. These cannot be translated back to OWLClass and there's no current implementation for translating back class expressions. Tweaking the code to remove the exceptions is doable but for your ontology example you'd always get back empty nodes, which isn't very informative.

I have removed the exception throwing in the latest version 5 branch, however I doubt this is sufficient for your needs.

Sources

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Source: Stack Overflow

Solution Source
Solution 1 Ignazio

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