01 /* This file is part of the project "Hilbert II" - http://www.qedeq.org
02 *
03 * Copyright 2000-2011, Michael Meyling <mime@qedeq.org>.
04 *
05 * "Hilbert II" is free software; you can redistribute
06 * it and/or modify it under the terms of the GNU General Public
07 * License as published by the Free Software Foundation; either
08 * version 2 of the License, or (at your option) any later version.
09 *
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 a predicate is already defined.
21 *
22 * @author Michael Meyling
23 */
24 public interface PredicateExistenceChecker {
25
26 /**
27 * Check if a predicate is already defined.
28 *
29 * @param name Predicate name.
30 * @param arguments Number of operands for the predicate.
31 * @return Predicate is defined.
32 */
33 public boolean predicateExists(String name, int arguments);
34
35 /**
36 * Check if a predicate is already defined.
37 *
38 * @param predicate Predicate.
39 * @return Predicate is defined.
40 */
41 public boolean predicateExists(PredicateKey predicate);
42
43 /**
44 * Check if given predicate key has an initial predicate definition.
45 *
46 * @param predicate Predicate.
47 * @return Predicate is defined and is an initial predicate definition.
48 */
49 public boolean isInitialPredicate(final PredicateKey predicate);
50
51 }
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