LightestClauseHeuristic.java

package aima.core.logic.fol.inference.otter;

import java.util.Set;

import aima.core.logic.fol.kb.data.Clause;

/**
 * Heuristic for selecting lightest clause from SOS. To avoid recalculating the
 * lightest clause on every call, the interface supports defining the initial
 * sos and updates to that set so that it can maintain its own internal data
 * structures to allow for incremental re-calculation of the lightest clause.
 * 
 * @author Ciaran O'Reilly
 * 
 */
public interface LightestClauseHeuristic {

	/**
	 * Get the lightest clause from the SOS
	 * 
	 * @return the lightest clause.
	 */
	Clause getLightestClause();

	/**
	 * SOS life-cycle methods allowing implementations of this interface to
	 * incrementally update the calculation of the lightest clause as opposed to
	 * having to recalculate each time.
	 * 
	 * @param clauses
	 */
	void initialSOS(Set<Clause> clauses);

	void addedClauseToSOS(Clause clause);

	void removedClauseFromSOS(Clause clause);
}