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Utilities to present tracing results (encoded proofs) to the user
There is a newer version: 0.35.0
/*-
 * #%L
 * ELK Proofs Package
 * $Id:$
 * $HeadURL:$
 * %%
 * Copyright (C) 2011 - 2017 Department of Computer Science, University of Oxford
 * %%
 * 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.
 * #L%
 */
package org.semanticweb.elk.proofs;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.LinkedList;
import java.util.List;
import java.util.Queue;
import java.util.Set;

import org.liveontologies.puli.BaseProof;
import org.liveontologies.puli.Inference;
import org.liveontologies.puli.Inferences;
import org.liveontologies.puli.ModifiableProof;
import org.liveontologies.puli.Proof;
import org.semanticweb.elk.exceptions.ElkException;
import org.semanticweb.elk.owl.interfaces.ElkAxiom;
import org.semanticweb.elk.reasoner.Reasoner;
import org.semanticweb.elk.reasoner.entailments.model.Entailment;
import org.semanticweb.elk.reasoner.entailments.model.EntailmentInference;
import org.semanticweb.elk.reasoner.entailments.model.HasReason;
import org.semanticweb.elk.reasoner.proof.ReasonerProof;
import org.semanticweb.elk.reasoner.query.VerifiableQueryResult;
import org.semanticweb.elk.reasoner.tracing.Conclusion;
import org.semanticweb.elk.reasoner.tracing.TracingInference;
import org.semanticweb.elk.util.collections.ArrayHashSet;

/**
 * Combines {@link org.semanticweb.elk.reasoner.tracing.TracingProof
 * TracingProof} and a {@link Proof} over {@link EntailmentInference}s into a
 * {@link Proof} over common conclusions and justifies the
 * {@link TracingInference}s with their axioms.
 * 
 * @author Peter Skocovsky
 */
public class InternalProof implements Proof> {

	private final Reasoner reasoner_;
	private final ElkAxiom goal_;

	private final ModifiableProof> proof_ = new BaseProof>();

	public InternalProof(final Reasoner reasoner, final ElkAxiom goal)
			throws ElkException {
		this.reasoner_ = reasoner;
		this.goal_ = goal;
		VerifiableQueryResult result = reasoner.checkEntailment(goal);
		
		try {
			final Entailment entailment = result.getEntailment();
			if (entailment == null) {
				// goal is not proved -> empty proof
				return;
			}
			proof_.produce(Inferences.create("Goal inference", goal_,
					Arrays.asList(entailment)));
			processEntailment(entailment, result.getEvidence(false));
		} finally {
			result.unlock();
		}
	}

	private void processEntailment(final Entailment goal,
			final ReasonerProof evidence) throws ElkException {

		final Set entailmentDone = new ArrayHashSet();
		final Queue entailmentToDo = new LinkedList();
		final Set tracingDone = new ArrayHashSet();
		final Queue tracingToDo = new LinkedList();

		if (entailmentDone.add(goal)) {
			entailmentToDo.add(goal);
		}

		Entailment entailment;
		while ((entailment = entailmentToDo.poll()) != null) {
			for (final EntailmentInference inf : evidence
					.getInferences(entailment)) {

				final Conclusion reason = getReason(inf);

				final List premises = inf.getPremises();
				final List