1 /* This file is part of the project "Hilbert II" - http://www.qedeq.org" target="alexandria_uri">http://www.qedeq.org 2 * 3 * Copyright 2000-2014, Michael Meyling <mime@qedeq.org>. 4 * 5 * "Hilbert II" is free software; you can redistribute 6 * it and/or modify it under the terms of the GNU General Public 7 * License as published by the Free Software Foundation; either 8 * version 2 of the License, or (at your option) any later version. 9 * 10 * This program is distributed in the hope that it will be useful, 11 * but WITHOUT ANY WARRANTY; without even the implied warranty of 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 * GNU General Public License for more details. 14 */ 15 16 package org.qedeq.kernel.se.base.module; 17 18 import org.qedeq.kernel.se.base.list.Element; 19 20 /** 21 * Wraps a formula. Such an object is build out of 22 * {@link org.qedeq.kernel.se.base.list.Element}s. 23 * 24 * @author Michael Meyling 25 */ 26 public interface Formula { 27 28 /** 29 * Get formula or term. 30 * 31 * @return Word that should be a formula. 32 */ 33 public Element getElement(); 34 }