LTL2BA - Forked and, to distinguish from the original, referred to as ltl2gba.
Modified by Scott C. Livingston, Caltech, USA.
Copyright (c) 2013  Scott C. Livingston
Available at https://github.com/slivingston/ltl2gba

A new version sequence has begun to avoid confusion with the original LTL2BA.
It is of the form 1.2-scl.  Consult the last section of this README
file for a list of changes.


1. LICENSE

LTL2BA - Version 1.0 - October 2001
Written by Denis Oddoux, LIAFA, France                                 
Copyright (c) 2001  Denis Oddoux                                       
     
LTL2BA - Version 1.1 - August 2007
Modified by Paul Gastin, LSV, France                                 
Copyright (c) 2007  Paul Gastin                                       
Available at http://www.lsv.ens-cachan.fr/~gastin/ltl2ba
                                                                  
This program 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. GNU GPL is included in this 
distribution, in a file called 'LICENSE'
                                                                       
This program 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 this program; if not, write to the Free Software            
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA

The LTL2BA software was written by Denis Oddoux and modified by Paul
Gastin.  It is based on the translation algorithm presented at CAV '01:
	P.Gastin and D.Oddoux
	"Fast LTL to Büchi Automata Translation" 
	in 13th International Conference on Computer Aided Verification, CAV 2001, 
	G. Berry, H. Comon, A. Finkel (Eds.)
	Paris, France, July 18-22, 2001, 
	Proceedings - LNCS 2102, pp. 53-65
                                                                       
Send bug-reports and/or questions to Paul Gastin   
http://www.lsv.ens-cachan.fr/~gastin

Part of the code included is issued from the SPIN software Version 3.4.1
The SPIN software is written by Gerard J. Holzmann, originally as part
of ``Design and Validation of Protocols,'' ISBN 0-13-539925-4,
1991, Prentice Hall, Englewood Cliffs, NJ, 07632
Here are the files that contain some code from Spin v3.4.1 :

	cache.c  (originally tl_cache.c)
	lex.c    (           tl_lex.c  )
	ltl2ba.h (	     tl.h      )
	main.c   (	     tl_main.c )
	mem.c	 (	     tl_mem.c  )
	parse.c  (	     tl_parse.c)
	rewrt.c  (	     tl_rewrt.c)
	trans.c	 (	     tl_trans.c)

2. COMPILING

open the archive :
> gunzip ltl2ba-1.1.tar.gz
> tar xf ltl2ba-1.1.tar
> cd ltl2ba-1.1

compile the program
> make

3. EXECUTING

run the program
> ./ltl2gba -f "formula"

The formula is an LTL formula, and may contain propositional symbols, 
boolean operators, temporal operators, and parentheses.
The syntax used is the one used in the 'Spin' model-checker

Propositonal Symbols:
        true, false
	any lowercase string

Boolean operators:
        !   (negation)
        ->  (implication)
	<-> (equivalence)
        &&  (and)
        ||  (or)

Temporal operators:
        []  (always)
        <>  (eventually)
        U   (until)
        V   (release)
        X   (next)

Use spaces between any symbols.

The result is a never claim in Promela that can be given to the Spin
model checker to verify properties on a system.  Other output formats
are available; consult the last section of this README file.

run the command
> ./ltl2gba -h
to see the possible options for executing the program

4. CHANGES IN VERSION 1.1

- fixing a bug in the way sets were used for strongly connected components. Thanks to Joachim Klein (klein@tcs.inf.tu-dresden.de) who found the bug and proposed a patch to fix it.
- fixing a bug in the simplification with strongly connected components for the generalized Büchi automaton. 
- improving the simplification with strongly connected components for the generalized Büchi automaton.
- using getrusage to compute running times for the statistics
- some other minor updates.

5. CHANGES IN VERSION 1.2-scl

- add "-t TYPE" flag for selection of output formats besides Promela
  never claims.  By default the final nondeterministic Buechi
  automaton is dumped in the requested format.  Possible formats are
  - spin: (default), never claim as in previous versions;
  - dot: Graphviz DOT (http://graphviz.org/);
  - gexf: Gephi GEXF (http://gexf.net/format/).