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.bo.logic.common;
17
18
19 /**
20 * Check if operators are already defined and well formed.
21 * <p>
22 * If {@link #identityOperatorExists()} returns <code>true</code> then
23 * the call to {@link #predicateExists(String, int)} with the arguments
24 * {@link #getIdentityOperator()} and 2 must return <code>true</code>.
25 *
26 * @author Michael Meyling
27 */
28 public interface ExistenceChecker extends PredicateExistenceChecker, FunctionExistenceChecker,
29 ClassOperatorExistenceChecker, IdentityOperatorExistenceChecker, RuleExistenceChecker {
30
31 /** Name of identity operator. */
32 public static final String NAME_EQUAL = "equal";
33
34
35 }