code: package it.unibz.inf.ontop.spec.ontology;
  
  /*
   * #%L
   * ontop-obdalib-core
   * %%
   * Copyright (C) 2009 - 2014 Free University of Bozen-Bolzano
   * %%
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   * 
   *      http://www.apache.org/licenses/LICENSE-2.0
   * 
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   * #L%
   */
  
  /**
   * Represents partially ordered classes and object and data properties
   * 
   * isTop/isBottom are two syntactic checks for the largest/smallest element in the partial order  
   * 
   * @author Roman Kontchakov
   *
   */
  
  
  public interface DescriptionBT extends Description {
  	/**
  	 * checks (syntactically, irrespective of any ontology) whether the class or property expression 
  	 *       is equivalent to owl:Nothing/owl:BottomObjectProperty/owl:BottomDataProperty
  	 * 
  	 * @return true if the expression is equivalent to the smallest element 
  	 */
  	boolean isBottom();
  	
  	/**
  	 * checks (syntactically, irrespective of any ontology) whether the class or property expression 
  	 *          is equivalent to owl:Thing/owl:TopObjectProperty/owl:TopDataProperty
  	 * 
  	 * @return true if the expression is equivalent to largest element
  	 */
  	boolean isTop();
  }
  