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 * Logical and term operators. These strings might occur as values for 20 * {@link org.qedeq.kernel.se.base.list.ElementList#getOperator()}. 21 * 22 * @author Michael Meyling 23 */ 24 public interface Operators { 25 26 /** Operator string for logical "and". */ 27 public static final String CONJUNCTION_OPERATOR = "AND"; 28 29 /** Operator string for logical "or". */ 30 public static final String DISJUNCTION_OPERATOR = "OR"; 31 32 /** Operator string for logical implication. */ 33 public static final String IMPLICATION_OPERATOR = "IMPL"; 34 35 /** Operator string for logical equivalence. */ 36 public static final String EQUIVALENCE_OPERATOR = "EQUI"; 37 38 /** Operator string for logical negation. */ 39 public static final String NEGATION_OPERATOR = "NOT"; 40 41 /** Operator string for logical "all" operator. */ 42 public static final String UNIVERSAL_QUANTIFIER_OPERATOR = "FORALL"; 43 44 /** Operator string for logical "exists" operator. */ 45 public static final String EXISTENTIAL_QUANTIFIER_OPERATOR = "EXISTS"; 46 47 /** Operator string for logical "exists unique" operator. */ 48 public static final String UNIQUE_EXISTENTIAL_QUANTIFIER_OPERATOR = "EXISTSU"; 49 50 /** Operator string for predicate constants. */ 51 public static final String PREDICATE_CONSTANT = "PREDCON"; 52 53 /** Operator string for predicate variables. */ 54 public static final String PREDICATE_VARIABLE = "PREDVAR"; 55 56 /** Operator string for subject variables. */ 57 public static final String SUBJECT_VARIABLE = "VAR"; 58 59 /** Operator string for function constants. */ 60 public static final String FUNCTION_CONSTANT = "FUNCON"; 61 62 /** Operator string for function constants. */ 63 public static final String FUNCTION_VARIABLE = "FUNVAR"; 64 65 /** Operator string for class operator. */ 66 public static final String CLASS_OP = "CLASS"; 67 68 /** Operator string for meta variables. */ 69 public static final String META_VARIABLE = "METAVAR"; 70 71 }