org.semanticweb.owlapi.util.InferredObjectPropertyCharacteristicAxiomGenerator Maven / Gradle / Ivy

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/*
 * This file is part of the OWL API.
 *
 * The contents of this file are subject to the LGPL License, Version 3.0.
 *
 * Copyright (C) 2011, The University of Manchester
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see http://www.gnu.org/licenses/.
 *
 *
 * Alternatively, the contents of this file may be used under the terms of the Apache License, Version 2.0
 * in which case, the provisions of the Apache License Version 2.0 are applicable instead of those above.
 *
 * Copyright 2011, University of Manchester
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.semanticweb.owlapi.util;

import java.util.Arrays;
import java.util.HashSet;
import java.util.Set;

import org.semanticweb.owlapi.model.AxiomType;
import org.semanticweb.owlapi.model.OWLAnonymousIndividual;
import org.semanticweb.owlapi.model.OWLAxiom;
import org.semanticweb.owlapi.model.OWLDataFactory;
import org.semanticweb.owlapi.model.OWLObjectProperty;
import org.semanticweb.owlapi.model.OWLObjectPropertyCharacteristicAxiom;
import org.semanticweb.owlapi.reasoner.OWLReasoner;

/**
 * @author Matthew Horridge, The University Of Manchester, Bio-Health
 *         Informatics Group, Date: 27-Jul-2007
 */
public class InferredObjectPropertyCharacteristicAxiomGenerator
        extends
        InferredObjectPropertyAxiomGenerator {

    @Override
    protected void addAxioms(OWLObjectProperty entity, OWLReasoner reasoner,
            OWLDataFactory dataFactory,
            Set result) {
        addIfEntailed(dataFactory.getOWLFunctionalObjectPropertyAxiom(entity),
                reasoner, result);
        addIfEntailed(
                dataFactory.getOWLInverseFunctionalObjectPropertyAxiom(entity),
                reasoner, result);
        addIfEntailed(dataFactory.getOWLSymmetricObjectPropertyAxiom(entity),
                reasoner, result);
        addIfEntailed(dataFactory.getOWLAsymmetricObjectPropertyAxiom(entity),
                reasoner, result);
        addTransitiveAxiomIfEntailed(entity, reasoner, dataFactory, result);
        addIfEntailed(dataFactory.getOWLReflexiveObjectPropertyAxiom(entity),
                reasoner, result);
        addIfEntailed(dataFactory.getOWLIrreflexiveObjectPropertyAxiom(entity),
                reasoner, result);
    }

    protected void addTransitiveAxiomIfEntailed(OWLObjectProperty property,
            OWLReasoner reasoner, OWLDataFactory dataFactory,
            Set result) {
        OWLObjectPropertyCharacteristicAxiom axiom = dataFactory
                .getOWLTransitiveObjectPropertyAxiom(property);
        if (reasoner.isEntailmentCheckingSupported(axiom.getAxiomType())
                && reasoner.isEntailed(axiom)) {
            if (!triviallyTransitiveCheck(property, reasoner, dataFactory)) {
                result.add(axiom);
            }
        }
    }

    /**
     * Test to see if a property is only vacuously transitive; i.e. if there
     * cannot be any three individuals a,b,c such that foo(a,b) and foo(b,c) -
     * e.g. if the domain and range of foo are disjoint. .
     * 
     * @param property
     *        property to test
     * @param reasoner
     *        reasoner to use for testing
     * @param df
     *        data factory
     * @return true if property is trivially transitive, or if entailment
     *         checking for OWLObjectPropertyAssertionAxioms is not supported.
     */
    private boolean triviallyTransitiveCheck(OWLObjectProperty property,
            OWLReasoner reasoner, OWLDataFactory df) {
        if (!reasoner
                .isEntailmentCheckingSupported(AxiomType.OBJECT_PROPERTY_ASSERTION)) {
            return true;
        }
        OWLAnonymousIndividual a = df.getOWLAnonymousIndividual();
        OWLAnonymousIndividual b = df.getOWLAnonymousIndividual();
        OWLAnonymousIndividual c = df.getOWLAnonymousIndividual();
        Set trivialityCheckAxioms = new HashSet(
                Arrays.asList(
                        df.getOWLObjectPropertyAssertionAxiom(property, a, b),
                        df.getOWLObjectPropertyAssertionAxiom(property, b, c)));
        return !reasoner.isEntailed(trivialityCheckAxioms);
    }

    protected void addIfEntailed(OWLObjectPropertyCharacteristicAxiom axiom,
            OWLReasoner reasoner,
            Set result) {
        if (reasoner.isEntailmentCheckingSupported(axiom.getAxiomType())
                && reasoner.isEntailed(axiom)) {
            result.add(axiom);
        }
    }

    @Override
    public String getLabel() {
        return "Object property characteristics";
    }
}