ignazio1977/owlexplanation

An API and reference implementation for generating justifications for entailments in OWL ontologies

OWL Explanation

An API and reference implementation for generating justifications for entailments in OWL ontologies.

Maven Dependency

<dependency>
    <groupId>net.sourceforge.owlapi</groupId>
    <artifactId>owlexplanation</artifactId>
    <version>5.0.0</version>
</dependency>

Example Usage

import org.semanticweb.owl.explanation.api.*;
import org.semanticweb.owlapi.model.*;
import org.semanticweb.owlapi.reasoner.OWLReasonerFactory;

OWLReasonerFactory rf = ; // Get hold of a reasoner factory
OWLOntology ont = ; // Reference to an OWLOntology

// Create the explanation generator factory which uses reasoners provided by the specified
// reasoner factory
ExplanationGeneratorFactory<OWLAxiom> genFac = ExplanationManager.createExplanationGeneratorFactory(rf);

// Now create the actual explanation generator for our ontology
ExplanationGenerator<OWLAxiom> gen = genFac.createExplanationGenerator(ont);

// Ask for explanations for some entailment
OWLAxiom entailment ; // Get a reference to the axiom that represents the entailment that we want explanation for

// Get our explanations.  Ask for a maximum of 5.
Set<Explanation<OWLAxiom>> expl = gen.getExplanations(entailment, 5);

Explanations for Inconsistent Ontologies

To obtain explanations for inconsistent ontologies the InconsistentOntologyExplanationGeneratorFactory can be used. Ask for explanations for SubClassOf(owl:Thing owl:Nothing).

owlexplanation's Issues

Documentation/example needed

It would be great if some documentation/example code is provided on how to use the API. I have been struggling since a long time to understand the usage.

Explanations for Inconsistent Ontologies with OWL API 5.1.14

Hello,

I am trying to use this package for checking inconsistencies in an OWL 2 DL ontology. I am using OWL API 5.1.14 and owlexplanation 5.0.0 but I am failing to adapt an old example found on stackoverflow to OWL API v5.

Any help would be welcome.

UnsupportedAxiomTypeException: Unsupported type of axiom: EquivalentClasses

Hi Ignazio,

I am facing this issue which I can't figure out. Is the EquivalentClassAxiom supported by owlexplanation 5.0.0?

I get org.semanticweb.owl.explanation.impl.blackbox.checker.SatisfiabilityEntailmentChecker$UnsupportedAxiomTypeException: Unsupported type of axiom: EquivalentClasses

for the axiom EquivalentClasses(<http://stelios.org/onto.owl#Dog> <http://stelios.org/onto.owl#Rough> <http://stelios.org/onto.owl#Young>), of this ontology.

Keep in mind the ontology is randomly generated so don't bother making sense of any meaning in it.

I am using HermiT 1.4.5.519, OWLAPI 5.1.19 and Owlexplanation 5.0.0.

Thank you for your work.

There seems to be a bug in StructuralTypePriorityExpansionStrategy

The constructor of StructuralTypePriorityExpansionStrategy has a potential NullPointerException which is guaranteed to be generated if the Configuration Constructor public Configuration(EntailmentCheckerFactory<E> checkerFactory, Supplier<OWLOntologyManager> m) is used anywhere in the code.

Perhaps replace:
public StructuralTypePriorityExpansionStrategy(InitialEntailmentCheckStrategy initialEntailmentCheckStrategy,
Supplier<OWLOntologyManager> m) {
this.initialEntailmentCheckStrategy = initialEntailmentCheckStrategy;
this.m = m;
}

with:
public StructuralTypePriorityExpansionStrategy(InitialEntailmentCheckStrategy initialEntailmentCheckStrategy, Supplier<OWLOntologyManager> m) {
if(initialEntailmentCheckStrategy != null){
this.initialEntailmentCheckStrategy = initialEntailmentCheckStrategy;
}
this.m = m;
}

Null pointer exception

@ignazio1977 I am getting a Null Pointer Exception when trying to generate explanations. The code which fixes this issue probably isn't present in the version 5.0.0 of the dependency available in Maven repository.