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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 an value representing releases of this packaged version. So, 1.3.7.1 is the first release of the mavenized version of HermiT based on the 1.3.7 release of HermiT. 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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package rationals.transformations;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Set;

import rationals.Automaton;
import rationals.NoSuchStateException;
import rationals.State;
import rationals.Transition;

/**
 * This class allows to remove epsilon transitions in an automaton. Epsilon
 * transition are transitions (q , l , q') where l is null.
 * 
 * @author Yves Roos
 * @version 22032002
 */
public class EpsilonTransitionRemover implements UnaryTransformation {

    /*
     * (non-Javadoc)
     * 
     * @see rationals.transformations.UnaryTransformation#transform(rationals.Automaton)
     */
    public Automaton transform(Automaton a) {
        Automaton ret = new Automaton(); /* resulting automaton */
        Map /* < HashValue, State > */ sm = new HashMap();
        Set done = new HashSet();
        List todo = new ArrayList(); /* set of states to explore */
        Set cur = TransformationsToolBox.epsilonClosure(a.initials(), a);
        /* add cur as initial state of ret */
        State is = ret.addState(true,TransformationsToolBox.containsATerminalState(cur));
        HashValue hv = new HashValue(cur);
        sm.put(hv,is);
        todo.add(hv);
        do {
            HashValue s = (HashValue) todo.remove(0);
            State ns =  (State)sm.get(s);
            if(ns == null) {
                ns = ret.addState(false,TransformationsToolBox.containsATerminalState(s.s));
                sm.put(s,ns);
            }
            /* set s as explored */
            done.add(s);
            /* look for all transitions in s */
            Map /* < Object, Set > */trm = instructions(a.delta(s.s),a);
            Iterator it = trm.entrySet().iterator();
            while (it.hasNext()) {
                Map.Entry e = (Map.Entry) it.next();
                Object o = e.getKey();
                Set ar = (Set) e.getValue();
                /* compute closure of arrival set */
                ar = TransformationsToolBox.epsilonClosure(ar, a);
                hv = new HashValue(ar);
                /* retrieve state in new automaton from hashvalue */
                State ne = (State)sm.get(hv);
                if(ne == null) {
                    ne = ret.addState(false,TransformationsToolBox.containsATerminalState(ar));
                    sm.put(hv,ne);
                }
                try {
                    /* create transition */
                    ret.addTransition(new Transition(ns,o,ne));
                } catch (NoSuchStateException e1) {
                }
                /* explore new state */
                if(!done.contains(hv))
                    todo.add(hv);
            }
        } while (!todo.isEmpty());
        return ret;
    }

    private Map /* < Object, Set > */instructions(Set /* < Transition > */s,Automaton a) {
        Map /* < Object, Set > */m = new HashMap();
        Iterator it = s.iterator();
        while (it.hasNext()) {
            Transition tr = (Transition) it.next();
            Object l = tr.label();
            if (l != null) {
                Set st = (Set) m.get(l);
                if (st == null) {
                    st = a.getStateFactory().stateSet();
                    m.put(l,st);
                }
                /* add arrival state */
                st.add(tr.end());
            }
        }
        return m;
    }

}