SemanticEvaluationPolicy.java :  » Rule-Engine » Mandarax » org » mandarax » reference » Java Open Source

package org.mandarax.reference;


/*
 * Copyright (C) 1999-2004 <A href="http://www-ist.massey.ac.nz/JBDietrich" target="_top">Jens Dietrich</a>
 *
 * This library 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 2 of the License, or (at your option) any later version.
 *
 * This library 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 this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */
 
import java.io.Serializable;
import org.mandarax.kernel.*;
import org.mandarax.util.logging.LogCategories;
/**
 * Algorithm used by the inference engines to evaluate 'semantic' clauses 
 * and terms.
 * @author <A href="http://www-ist.massey.ac.nz/JBDietrich" target="_top">Jens Dietrich</A>
 * @version 3.4 <7 March 05>
 * @since 2.0
 */
public interface SemanticEvaluationPolicy extends LogCategories, Serializable {

  /**
   * Try to execute literals in the clause, and remove those literals if the
   * result ist true. E.g., the result of performing +[]-[L1,L2,2&lt4,L3]
   * would be +[]-[L1,L2,2&lt4,L3].
   * This method is used in the actual proof.
   * @param c a clause
   * @param session a session object
   * @param logOn indicates whether we should log
   * @return another clause
   */
  Clause evaluate(Clause c,Session session,boolean logOn) ;
  /**
   * Try to execute a complex term.
   * This method is used when applying unification in renamings
   * in the process of result set building.
   * @param ct a complex term
   * @param cs the clause set (context object)
   * @param session a session object
   * @param logOn indicates whether we should log
   * @return the term
   */
  Term evaluate(ComplexTerm c,ClauseSet cs, Session session,boolean logOn) ;
  /**
   * Try to unify two terms by evaluating them and comparing the results. 
   * @param t1 the first term
   * @param t2 the second term
   * @param session a session object
   * @return a boolean - true if the terms represent the same object
   * @param logOn indicates whether we should log
   */
  boolean evaluateAndCompare(Term t1,Term t2,Session session,boolean logOn) ;
}