code: /**
   * <copyright>
   * Copyright (c) 2010-2014 Henshin developers. All rights reserved. 
   * This program and the accompanying materials are made available 
   * under the terms of the Eclipse Public License v1.0 which 
   * accompanies this distribution, and is available at
   * http://www.eclipse.org/legal/epl-v10.html
   * </copyright>
   */
  package org.eclipse.emf.henshin.interpreter.matching.constraints;
  
  /**
   * Interface for binary constraints.
   * 
   * @author Enrico Biermann, Christian Krause
   */
  public interface BinaryConstraint extends Constraint {
  	
  	/**
  	 * Evaluates the constraint between the given domain slots.
  	 * BinaryConstraints may only be checked <i>after</i> the 
  	 * source slot has been locked.
  	 * 
  	 * @param source The (locked) domain slot initiating the evaluation.
  	 * @param target The domain slot which domain will be checked.
  	 * @return <code>true</code>, if the constraint is compatible with the given slot pair.
  	 */
  	boolean check(DomainSlot source, DomainSlot target);
  	
  }
  