001package net.sf.cpsolver.ifs.constant;
002
003/**
004 * Extension of a variable with the possibility to have a constant value.
005 * 
006 * Such variables are excluded from the solver process, however, they can be
007 * included in constraints.
008 * 
009 * @version IFS 1.2 (Iterative Forward Search)<br>
010 *          Copyright (C) 2006 - 2010 Tomáš Müller<br>
011 *          <a href="mailto:muller@unitime.org">muller@unitime.org</a><br>
012 *          <a href="http://muller.unitime.org">http://muller.unitime.org</a><br>
013 * <br>
014 *          This library is free software; you can redistribute it and/or modify
015 *          it under the terms of the GNU Lesser General Public License as
016 *          published by the Free Software Foundation; either version 3 of the
017 *          License, or (at your option) any later version. <br>
018 * <br>
019 *          This library is distributed in the hope that it will be useful, but
020 *          WITHOUT ANY WARRANTY; without even the implied warranty of
021 *          MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
022 *          Lesser General Public License for more details. <br>
023 * <br>
024 *          You should have received a copy of the GNU Lesser General Public
025 *          License along with this library; if not see <http://www.gnu.org/licenses/>.
026 * 
027 */
028
029public interface ConstantVariable {
030    /** True, if the variable is constant. */
031    public boolean isConstant();
032}