From 3e31a6d7df0fda4f3acd6dc3693cca0d08caac2d Mon Sep 17 00:00:00 2001
From: Joachim Klein <klein@tcs.inf.tu-dresden.de>
Date: Thu, 11 Feb 2016 12:05:20 +0000
Subject: [PATCH] automata.LTL2NBA: expose jltl2ba NBA generation (for non-prob
 LTL checking)

git-svn-id: https://www.prismmodelchecker.org/svn/prism/prism/trunk@11180 bbc10eb1-c90d-0410-af57-cb519fbb1720
---
 prism/src/automata/LTL2NBA.java | 84 +++++++++++++++++++++++++++++++++
 1 file changed, 84 insertions(+)
 create mode 100644 prism/src/automata/LTL2NBA.java

diff --git a/prism/src/automata/LTL2NBA.java b/prism/src/automata/LTL2NBA.java
new file mode 100644
index 00000000..3d251892
--- /dev/null
+++ b/prism/src/automata/LTL2NBA.java
@@ -0,0 +1,84 @@
+//==============================================================================
+//	
+//	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.APSet;
+import jltl2ba.Alternating;
+import jltl2ba.Buchi;
+import jltl2ba.Generalized;
+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.");
+		}
+
+		SimpleLTL ltlSimple = ltl.convertForJltl2ba();
+		APSet apset = ltlSimple.getAPs();
+
+		Alternating a = new Alternating(ltlSimple, apset);
+		// a.print(System.out);
+		Generalized g = new Generalized(a);
+		// g.print(System.out, apset);
+		Buchi b = new Buchi(g);
+		// b.print_spin(System.out, apset);
+		NBA nba = b.toNBA(apset);
+		// nba.print(System.out);
+		
+		// jltl2ba should never produce disjoint NBA,
+		// i.e., where some states are not reachable
+		// from the intial state, so we want to fail
+		// later if the NBA is discovered to be disjoint:
+		nba.setFailIfDisjoint(true);
+
+		return nba;
+	}
+}