    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}