We are pleased to announce the release of Spot 0.7.1.
Spot is a model-checking library developed collaboratively by LRDE and
LIP6. It provides algorithms and data structures to implement the
automata-theoretic approach to LTL model checking.
This is a quick maintenance release mainly to fix some configuration
problem if you already had a previous version of Spot installed, and
to address a more serious bug in WDBA minimization.
We have also integrated some minor features that should ease
comparisons with the Büchi Store. But beware: the Büchi Store (and
Goal) uses right-associativity for operators "W", "U", and "R", while
Spot applies left-associativity. A formula like "p W q U r" will be
interpreted differently. We will probably switch to
right-associativity in a future version in order to get closer to the
PSL standard.
You can find the new release here:
http://spot.lip6.fr/dl/spot-0.7.1.tar.gz (14MB)
New in spot 0.7.1 (2001-02-07):
* The LTL parser will accept operator ~ (for not) as well
as --> and <--> (for implication and equivalence), allowing
formulae from the Büchi Store to be read directly.
* The neverclaim parser will accept guards of the form
:: !(...) -> goto ...
instead of the more commonly used
:: (!(...)) -> goto ...
This makes it possible to read neverclaims provided by the Büchi Store.
* A new ltl2tgba option, -kt, will count the number of "sub-transitions".
I.e., a transition labelled by "true" counts for 4 "sub-transitions"
if the automaton uses 2 atomic propositions.
* Bugs fixed:
- Fix segfault during WDBA minimization on automata with useless states.
- Use the included BuDDy library if the one already installed
is older than the one distributed with Spot 0.7.
- Fix two typos in the code of the CGI scripts.
--
Alexandre Duret-Lutz
We are pleased to announce the release of Spot 0.7.
Spot is a model-checking library developed collaboratively by LRDE and
LIP6. It provides algorithms and data structures to implement the
automata-theoretic approach for LTL model checking.
Highlights in this release include some speed improvements, and
a minimization of WDBA (weak deterministic Büchi automata).
The online translator has also been rewritten.
You can find the new release here:
http://spot.lip6.fr/dl/spot-0.7.tar.gz
New in spot 0.7 (2011-02-01):
* Spot is now able to read an automaton expressed as a Spin neverclaim.
* The "experimental" Kripke structure introduced in Spot 0.5 has
been rewritten, and is no longer experimental. We have a
developement version of checkpn using it, and it should be
released shortly after Spot 0.7.
* The function to_spin_string(), that outputs an LTL formula using
Spin's syntax, now takes an optional argument to request
parentheses at all levels.
* src/ltltest/genltl is a new tool that generates some interesting
families of LTL formulae, for testing purpose.
* bench/ltlclasses/ uses the above tool to conduct the same benchmark
as in the DepCoS'09 paper by Cichoń et al. The resulting benchmark
completes in 12min, while it tooks days (or exhausted the memory)
when the paper was written (they used Spot 0.4).
* Degeneralization has again been improved in two ways:
- It will merge degeneralized transitions that can be merged.
- It uses a cache to speed up the improvement introduced in 0.6.
* An implementation of Dax et al.'s paper for minimizing obligation
formulae has been integrated. Use ltl2tgba -Rm to enable this
optimization from the command-line; it will have no effect if the
property is not an obligation.
* bench/wdba/ conducts a benchmark similar to the one on Dax's
webpage, comparing the size of the automata expressing obligation
formula before and after minimization. See bench/wdba/README for
results.
* Using similar code, Spot can now construct deterministic monitors.
* New ltl2tgba options:
-XN: read an input automaton as a neverclaim.
-C, -CR: Compute (and display) a counterexample after running the
emptiness check. With -CR, the counterexample will be
replayed on the automaton to ensure it is correct
(previous version would always compute a replay a
counterexample when emptiness-check was enabled)
-ks: traverse the automaton to compute its number of states and
transitions (this is faster than -k which will also count
SCCs and paths).
-M: Build a deterministic monitor.
-O: Tell whether a formula represents a safety, guarantee, or
obligation property.
-Rm: Minimize automata representing obligation properties.
* The on-line tool to translate LTL formulae into automata
has been rewritten and is now at http://spot.lip6.fr/ltl2tgba.html
It requires a javascript-enabled browser.
* Bug fixes:
- Location of the errors messages in the TGBA parser where inaccurate.
- Various warning fixes for different versions of GCC and Clang.
- The neverclaim output with ltl2tgba -N or -NN used to ignore any
automaton simplification performed after degeneralization.
- The formula simplification based on universality and eventuality
had a quadratic run-time.
--
Alexandre Duret-Lutz
