code: //==============================================================================
  //	
  //	Copyright (c) 2016-
  //	Authors:
  //	* Joachim Klein <klein@tcs.inf.tu-dresden.de> (TU Dresden)
  //	
  //------------------------------------------------------------------------------
  //	
  //	This file is part of PRISM.
  //	
  //	PRISM is free software; you can redistribute it and/or modify
  //	it under the terms of the GNU General Public License as published by
  //	the Free Software Foundation; either version 2 of the License, or
  //	(at your option) any later version.
  //	
  //	PRISM is distributed in the hope that it will be useful,
  //	but WITHOUT ANY WARRANTY; without even the implied warranty of
  //	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  //	GNU General Public License for more details.
  //	
  //	You should have received a copy of the GNU General Public License
  //	along with PRISM; if not, write to the Free Software Foundation,
  //	Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  //	
  //==============================================================================
  
  package automata;
  
  import jltl2ba.SimpleLTL;
  import jltl2dstar.NBA;
  import parser.Values;
  import parser.ast.Expression;
  import prism.PrismComponent;
  import prism.PrismException;
  import prism.PrismNotSupportedException;
  
  /**
   * Infrastructure for constructing non-deterministic Büchi automata for LTL formulas.
   */
  public class LTL2NBA extends PrismComponent
  {
  
  	public LTL2NBA(PrismComponent parent) throws PrismException {
  		super(parent);
  	}
  
  	/**
  	 * Convert an LTL formula into a non-deterministic Büchi automaton.
  	 * The LTL formula is represented as a PRISM Expression,
  	 * in which atomic propositions are represented by ExpressionLabel objects.
  	 * @param ltl the formula
  	 * @param constantValues the values of constants, may be {@code null}
  	 */
  	public NBA convertLTLFormulaToNBA(Expression ltl, Values constantValues) throws PrismException
  	{
  		if (Expression.containsTemporalTimeBounds(ltl)) {
  			throw new PrismNotSupportedException("LTL with time bounds currently not supported for LTL model checking.");
  		}
  
  		// convert to jltl2ba LTL, simplify formula
  		SimpleLTL ltlSimple = ltl.convertForJltl2ba().simplify();
  		return ltlSimple.toNBA();
  	}
  }
  