content: /**
   * Copyright (c) 2016, the Alpha Team.
   * All rights reserved.
   *
   * Additional changes made by Siemens.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions are met:
   *
   * 1) Redistributions of source code must retain the above copyright notice, this
   *    list of conditions and the following disclaimer.
   *
   * 2) Redistributions in binary form must reproduce the above copyright notice,
   *    this list of conditions and the following disclaimer in the documentation
   *    and/or other materials provided with the distribution.
   *
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
   * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
   * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
   * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
   * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
   * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
   * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
   * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   */
  package at.ac.tuwien.kr.alpha.core.solver;
  
  import at.ac.tuwien.kr.alpha.core.common.Truth;
  
  public enum ThriceTruth implements Truth {
  	TRUE("T", true),
  	FALSE("F", false),
  	MBT("M", true);
  
  	private final String asString;
  	private final boolean asBoolean;
  
  	ThriceTruth(String asString, boolean asBoolean) {
  		this.asString = asString;
  		this.asBoolean = asBoolean;
  	}
  
  	@Override
  	public boolean toBoolean() {
  		return asBoolean;
  	}
  
  	@Override
  	public String toString() {
  		return asString;
  	}
  
  	public static ThriceTruth valueOf(boolean value) {
  		return value ? TRUE : FALSE;
  	}
  
  	/**
  	 * @return true if this is MBT.
  	 */
  	public boolean isMBT() {
  		return this == ThriceTruth.MBT;
  	}
  
  	/**
  	 * Returns true if the two truth values are not compatible with each other.
  	 * Each truth value is compatible with itself and both MBT and TRUE are compatible. All other combinations are
  	 * conflicting.
  	 * @param value1 the first truth value.
  	 * @param value2 the second truth value.
  	 * @return true iff first and second truth value are conflicting (i.e., not compatible).
  	 */
  	public static boolean isConflicting(ThriceTruth value1, ThriceTruth value2) {
  		return (FALSE == value1 || FALSE == value2) && value1 != value2;
  	}
  }