如何从HermiT推理器获取含ObjectComplementOf的否定推理结果？

我的尝试代码 #

OWLOntologyManager manager = OWLManager.createOWLOntologyManager();
dataFactory = manager.getOWLDataFactory();
IRI iri = IRI.create("http://www.test.owl");
OWLOntology ontology = manager.createOntology(iri);

OWLClass clsA = dataFactory.getOWLClass(IRI.create(iri + "#A"));
OWLClass clsB = dataFactory.getOWLClass(IRI.create(iri + "#B"));
OWLAxiom axiom = dataFactory.getOWLSubClassOfAxiom(clsA, clsB.getComplementNNF());

OWLIndividual john = dataFactory.getOWLNamedIndividual(IRI.create(iri + "#JOHN"));
OWLClassAssertionAxiom assertionAxiom = dataFactory.getOWLClassAssertionAxiom(clsA, john);

ontology.add(axiom);
ontology.add(assertionAxiom);

OWLReasonerFactory reasoner_factory = new ReasonerFactory();
OWLReasoner reasoner = reasoner_factory.createReasoner(ontology);

OWLOntology inferred_ontology = manager.createOntology();

// Create an inferred axiom generator, and add the generators of choice.
List<InferredAxiomGenerator<? extends OWLAxiom>> gens = new ArrayList<>();
gens.add(new InferredSubClassAxiomGenerator());
gens.add(new InferredClassAssertionAxiomGenerator());
gens.add(new InferredDisjointClassesAxiomGenerator());
gens.add(new InferredEquivalentClassAxiomGenerator());

// Create the inferred ontology generator, and fill the empty ontology.
InferredOntologyGenerator iog = new InferredOntologyGenerator(reasoner, gens);
iog.fillOntology(dataFactory, inferred_ontology);

整理后的推理结果 #

//KB:   A SubClassOf not(B), A(JOHN)
ENTAILMENTS:{
    SubClassOf(A owl:Thing),
    SubClassOf(B owl:Thing),
    DisjointClasses(A owl:Nothing),
    DisjointClasses(B owl:Nothing),
    DisjointClasses(A B),
    ClassAssertion(owl:Thing JOHN),
    ClassAssertion(A JOHN)
}

问题 #

如何获取ClassAssertion(ObjectComplementOf(B) JOHN)这一断言？

解决方案 #

默认的InferredClassAssertionAxiomGenerator仅生成命名类的实例断言，不会处理ObjectComplementOf(B)这类匿名否定类。要获取目标断言，可通过以下两种方式实现：

方式一：直接调用推理器API验证并手动添加 #

构造否定类表达式后，调用推理器的isInstanceOf方法验证个体归属，再手动将断言添加到推理后的本体中：

// 构造否定类表达式：not(B)
OWLClassExpression notB = dataFactory.getOWLObjectComplementOf(clsB);
// 验证JOHN是否属于not(B)
boolean isJohnNotB = reasoner.isInstanceOf(john, notB);
if (isJohnNotB) {
    // 生成并添加目标断言
    OWLClassAssertionAxiom inferredAxiom = dataFactory.getOWLClassAssertionAxiom(notB, john);
    inferred_ontology.add(inferredAxiom);
}

方式二：自定义推断公理生成器 #

若需批量生成所有否定类的实例断言，可自定义InferredAxiomGenerator，遍历个体和类并验证实例关系：

class InferredNegatedClassAssertionGenerator extends InferredAxiomGenerator<OWLClassAssertionAxiom> {
    @Override
    protected void addAxioms(OWLReasoner reasoner, OWLDataFactory dataFactory, Set<OWLClassAssertionAxiom> axioms) {
        // 遍历本体中的所有个体
        for (OWLIndividual individual : reasoner.getRootOntology().getIndividualsInSignature()) {
            // 遍历所有命名类，生成其否定类并验证实例关系
            for (OWLClass cls : reasoner.getRootOntology().getClassesInSignature()) {
                OWLClassExpression notCls = dataFactory.getOWLObjectComplementOf(cls);
                if (reasoner.isInstanceOf(individual, notCls)) {
                    axioms.add(dataFactory.getOWLClassAssertionAxiom(notCls, individual));
                }
            }
        }
    }

    @Override
    public String getLabel() {
        return "Inferred Negated Class Assertions";
    }
}

将自定义生成器添加到生成器列表即可：

gens.add(new InferredNegatedClassAssertionGenerator());

内容的提问来源于stack exchange，提问作者SteliosKts