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HermiT is reasoner for ontologies written using the Web Ontology Language (OWL). Given an OWL file, HermiT can determine whether or not the ontology is consistent, identify subsumption relationships between classes, and much more. This is the maven build of HermiT and is designed for people who wish to use HermiT from within the OWL API. It is now versioned in the main HermiT version repository, although not officially supported by the HermiT developers. The version number of this package is a composite of the HermiT version and a value representing the OWLAPI release it is compatible with. Note that the group id for the upstream HermiT is com.hermit-reasoner, while this fork is released under net.sourceforge.owlapi. This fork exists to allow HermiT users to use newer OWLAPI versions than the ones supported by the original HermiT codebase. This package includes the Jautomata library (http://jautomata.sourceforge.net/), and builds with it directly. This library appears to be no longer under active development, and so a "fork" seems appropriate. No development is intended or anticipated on this code base.

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/* Copyright 2008, 2009, 2010 by the Oxford University Computing Laboratory

   This file is part of HermiT.

   HermiT is free software: you can redistribute it and/or modify
   it under the terms of the GNU Lesser General Public License as published by
   the Free Software Foundation, either version 3 of the License, or
   (at your option) any later version.

   HermiT 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 Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public License
   along with HermiT.  If not, see .
*/
package org.semanticweb.HermiT.model;

import java.io.Serializable;
import java.util.HashSet;
import java.util.Set;

import org.semanticweb.HermiT.Prefixes;

/**
 * Represents a DL clause. The body is a conjunction of atoms and the head is a disjunction of atoms.
 */
public class DLClause implements Serializable {
    private static final long serialVersionUID=-4513910129515151732L;

    protected final Atom[] m_headAtoms;
    protected final Atom[] m_bodyAtoms;

    protected DLClause(Atom[] headAtoms,Atom[] bodyAtoms) {
        m_headAtoms=headAtoms;
        m_bodyAtoms=bodyAtoms;
    }
    /**
     * @return head length
     */
    public int getHeadLength() {
        return m_headAtoms.length;
    }
    /**
     * @param atomIndex atomIndex
     * @return head atom
     */
    public Atom getHeadAtom(int atomIndex) {
        return m_headAtoms[atomIndex];
    }
    /**
     * @return atoms
     */
    public Atom[] getHeadAtoms() {
        return m_headAtoms;
    }
    /**
     * @return body length
     */
    public int getBodyLength() {
        return m_bodyAtoms.length;
    }
    /**
     * @param atomIndex atomIndex
     * @return body atom
     */
    public Atom getBodyAtom(int atomIndex) {
        return m_bodyAtoms[atomIndex];
    }
    /**
     * @return body atoms
     */
    public Atom[] getBodyAtoms() {
        return m_bodyAtoms;
    }
    /**
     * @param safeMakingPredicate safeMakingPredicate
     * @return safe dl clause
     */
    public DLClause getSafeVersion(DLPredicate safeMakingPredicate) {
        Set variables=new HashSet<>();
        // collect all the variables that occur in the head into the set variables
        for (int headIndex=0;headIndex bottom
            if (m_bodyAtoms.length==2 && m_bodyAtoms[0].getArity()==2 && m_bodyAtoms[1].getArity()==2)
                return false;
            for (Atom bodyAtom : m_bodyAtoms)
                if (bodyAtom.getArity()!=1 || !(bodyAtom.getDLPredicate() instanceof DataRange)) 
                    return true;                
        }
        for (Atom headAtom : m_headAtoms) {
            DLPredicate predicate=headAtom.getDLPredicate(); 
            if (predicate instanceof AtLeast 
                    || predicate instanceof LiteralConcept 
                    || predicate instanceof AnnotatedEquality
                    || predicate instanceof NodeIDLessEqualThan
                    || predicate instanceof NodeIDsAscendingOrEqual) 
                return true;
            if (predicate instanceof Equality) {
                // could be a key, which we do not count as GCI
                // check if body uses the special named concept
                for (Atom bodyAtom : m_bodyAtoms) {
                    DLPredicate bodyPredicate=bodyAtom.getDLPredicate();
                    if (bodyAtom.getArity()==1 
                            && bodyPredicate instanceof AtomicConcept 
                            && ((AtomicConcept)bodyPredicate).equals(AtomicConcept.INTERNAL_NAMED))
                        return false;
                }
            }
            if (predicate instanceof DataRange) {
                // could be a data range inclusion or a universal, e.g., A -> for all dp.DR
                for (Atom bodyAtom : m_bodyAtoms) {
                    if (bodyAtom.getArity()==2)
                        return true;
                }
                return false;
            }
            if (predicate instanceof Role) // role inclusion
                return false;
        }
        return false;
    }
    /**
     * @return true if atomic concept inclusion
     */
    public boolean isAtomicConceptInclusion() {
        if (m_bodyAtoms.length==1 && m_headAtoms.length==1) {
            Atom bodyAtom=m_bodyAtoms[0];
            Atom headAtom=m_headAtoms[0];
            if (bodyAtom.getArity()==1 && headAtom.getArity()==1 && bodyAtom.getDLPredicate() instanceof AtomicConcept && headAtom.getDLPredicate() instanceof AtomicConcept) {
                Term argument=bodyAtom.getArgument(0);
                return argument instanceof Variable && argument.equals(headAtom.getArgument(0));
            }
        }
        return false;
    }
    /**
     * @return true if atomic role inclusion
     */
    public boolean isAtomicRoleInclusion() {
        if (m_bodyAtoms.length==1 && m_headAtoms.length==1) {
            Atom bodyAtom=m_bodyAtoms[0];
            Atom headAtom=m_headAtoms[0];
            if (bodyAtom.getArity()==2 && headAtom.getArity()==2 && bodyAtom.getDLPredicate() instanceof AtomicRole && headAtom.getDLPredicate() instanceof AtomicRole) {
                Term argument0=bodyAtom.getArgument(0);
                Term argument1=bodyAtom.getArgument(1);
                return argument0 instanceof Variable && argument1 instanceof Variable && !argument0.equals(argument1) && argument0.equals(headAtom.getArgument(0))  && argument1.equals(headAtom.getArgument(1));
            }
        }
        return false;
    }
    /**
     * @return true if atomic role inverse inclusion
     */
    public boolean isAtomicRoleInverseInclusion() {
        if (m_bodyAtoms.length==1 && m_headAtoms.length==1) {
            Atom bodyAtom=m_bodyAtoms[0];
            Atom headAtom=m_headAtoms[0];
            if (bodyAtom.getArity()==2 && headAtom.getArity()==2 && bodyAtom.getDLPredicate() instanceof AtomicRole && headAtom.getDLPredicate() instanceof AtomicRole) {
                Term argument0=bodyAtom.getArgument(0);
                Term argument1=bodyAtom.getArgument(1);
                return argument0 instanceof Variable && argument1 instanceof Variable && !argument0.equals(argument1) && argument0.equals(headAtom.getArgument(1))  && argument1.equals(headAtom.getArgument(0));
            }
        }
        return false;
    }
    /**
     * @return true if functional
     */
    public boolean isFunctionalityAxiom() {
        if (m_bodyAtoms.length==2 && m_headAtoms.length==1) {
            DLPredicate atomicRole=getBodyAtom(0).getDLPredicate();
            if (atomicRole instanceof AtomicRole) {
                if (getBodyAtom(1).getDLPredicate().equals(atomicRole) && (getHeadAtom(0).getDLPredicate() instanceof AnnotatedEquality)) {
                    Variable x=getBodyAtom(0).getArgumentVariable(0);
                    if (x!=null && x.equals(getBodyAtom(1).getArgument(0))) {
                        Variable y1=getBodyAtom(0).getArgumentVariable(1);
                        Variable y2=getBodyAtom(1).getArgumentVariable(1);
                        Variable headY1=getHeadAtom(0).getArgumentVariable(0);
                        Variable headY2=getHeadAtom(0).getArgumentVariable(1);
                        if (y1!=null && y2!=null && !y1.equals(y2) && headY1!=null && headY2!=null && ((y1.equals(headY1) && y2.equals(headY2)) || (y1.equals(headY2) && y2.equals(headY1))))
                            return true;
                    }
                }
            }
        }
        return false;
    }
    /**
     * @return true if inverse functional
     */
    public boolean isInverseFunctionalityAxiom() {
        if (getBodyLength()==2 && getHeadLength()==1) {
            DLPredicate atomicRole=getBodyAtom(0).getDLPredicate();
            if (atomicRole instanceof AtomicRole) {
                if (getBodyAtom(1).getDLPredicate().equals(atomicRole) && (getHeadAtom(0).getDLPredicate() instanceof AnnotatedEquality)) {
                    Variable x=getBodyAtom(0).getArgumentVariable(1);
                    if (x!=null && x.equals(getBodyAtom(1).getArgument(1))) {
                        Variable y1=getBodyAtom(0).getArgumentVariable(0);
                        Variable y2=getBodyAtom(1).getArgumentVariable(0);
                        Variable headY1=getHeadAtom(0).getArgumentVariable(0);
                        Variable headY2=getHeadAtom(0).getArgumentVariable(1);
                        if (y1!=null && y2!=null && !y1.equals(y2) && headY1!=null && headY2!=null && ((y1.equals(headY1) && y2.equals(headY2)) || (y1.equals(headY2) && y2.equals(headY1))))
                            return true;
                    }
                }
            }
        }
        return false;
    }
    /**
     * @param prefixes prefixes
     * @return toString
     */
    public String toString(Prefixes prefixes) {
        StringBuilder buffer=new StringBuilder();
        for (int headIndex=0;headIndex s_interningManager = new InterningManager() {
        @Override
        protected boolean equal(DLClause object1, DLClause object2) {
            if (object1.m_headAtoms.length!=object2.m_headAtoms.length || object1.m_bodyAtoms.length!=object2.m_bodyAtoms.length)
                return false;
            for (int index = object1.m_headAtoms.length - 1; index >= 0; --index)
                if (object1.m_headAtoms[index] != object2.m_headAtoms[index])
                    return false;
            for (int index = object1.m_bodyAtoms.length - 1; index >= 0; --index)
                if (object1.m_bodyAtoms[index] != object2.m_bodyAtoms[index])
                    return false;
            return true;
        }

        @Override
        protected int getHashCode(DLClause object) {
            int hashCode = 0;
            for (int index = object.m_bodyAtoms.length - 1; index >= 0; --index)
                hashCode += object.m_bodyAtoms[index].hashCode();
            for (int index = object.m_headAtoms.length - 1; index >= 0; --index)
                hashCode += object.m_headAtoms[index].hashCode();
            return hashCode;
        }
    };

    /**
     * @param headAtoms headAtoms
     * @param bodyAtoms bodyAtoms
     * @return dl clause
     */
    public static DLClause create(Atom[] headAtoms,Atom[] bodyAtoms) {
        return s_interningManager.intern(new DLClause(headAtoms,bodyAtoms));
    }
}