Version 2.5.3
Jun 16, 2011

We are happy to announce the availability of a new version of the NuSMV model checker. NuSMV version 2.5.3 is available from https://nusmv.fbk.eu.

NuSMV 2 extends the previous versions of NuSMV with several new features, most notably with the possibility of performing SAT-based Bounded Model Checking (see the Overview below).

This is a minor release that provides many bug fixes, some internals improvement, and a few new features.

The main changes are listed below. For details please refer to the ChangeLog.

New features

  • System commands

    • Command compute has been renamed check_compute. Old command compute is deprecated.
    • Command clean_bdd_cache has been renamed clean_sexp2bdd_cache
    • Added option -F <format> to command show_property, to print in tabular or xml formats.
    • Added options -t and -V to command show_vars, to print selected information about the variables in the model.
    • Added option -k <length> to command simulate, to make uniform all simulation commands. Old syntax simulate <length> is now deprecated.
    • Added options -r, -c <simp_constr> and -t <next_constr> to SAT-based simulation commands, both incremental and non incremental, in order to be more uniform with regard to the BDD-based ones.

  • Command line options and system variables

    • Command line option and system variable disable_bdd_cache have been renamed to disable_sexp2bdd_caching
    • New command line option and system variable disable_syntactic_checks which can improve performances by skipping checks on input files which are assumed to be syntactically correct by construction.
    • New command line option and system variable keep_single_value_vars to disable an optimization which by default converts enumerative variables to constants when their domain contains only a single element.
    • New system variable default_simulation_steps is used by simulation commands. Command simulate now considers it if simulation steps are not specified; command bmc_simulate considers it instead of variable bmc_length.
    • New system variable parser_is_lax can be used to force the parser to try completing parsing even with syntactic errors, reporting all found errors at the end.
    • New system variable prop_print_method can be used to select how properties are printed out.

  • Improvements (internals)

    • New algorithms to compute COI (Cone of Influence) have been implemented.
    • Encoding of scalar variables have been improved to fit with the BDD variable ordering. The new encoding proved to improve performances in many general cases.
    • Fixed BDD encoding of variables to trigger less re-orderings.
    • Some RBC operations now use much less stack space.
    • New Symbol Table implementation, with huge performances and memory improvements.
    • New system-widely-used NodeList implementation, which reduces global NuSMV memory usage

Bug fixes

About 30 bugs were fixed in this version. Many thanks to those users who reported issues, and helped improving NuSMV.

Here the most critical bug fixes are listed:

  • Fixed a bug in CTL counter example generation, which was surfacing in some cases.
  • Fixed a bug which was triggered when adding incorrect properties to te properties database.
  • Fixed bug in command bmc_pick_state when used with COI.
  • Fixed compilation errors on recent GNU/Linux distributions
  • Fixed compilation errors under Darwin.
  • Fixed many memory leaks.

Documentation

  • Added a FAQ containing a set of most frequently asked questions about NuSMV, and the SMV language.
  • Added to the User Manual the description of some missing operators like sizeof

Attachment

Overview

NuSMV is a re-implementation and extension of SMV, the first model checker based on BDDs. It has been designed to be an open architecture for model checking, which can be reliably used for the verification of industrial designs, as a core for custom verification tools, and as a test-bed for formal verification techniques.

NuSMV version 2 extends NuSMV with new model checking algorithms and techniques. It combines classical BDD-based symbolic techniques with SAT-based techniques. It also presents other new features: for instance, it allows for a more powerful manipulation of multiple models; it can generate flat models for the whole language; it allows for cone of influence reduction.

The BDD-based model checking component exploits the CUDD library developed by Fabio Somenzi at Colorado University. The SAT-based model checking component includes an RBC-based Bounded Model Checker, connected to a SAT solver to be compiled separately (instructions and building support are batteries included in NuSMV, details are underneath). The currently available SAT solvers are: + The ZCHAFF SAT library developed by the Princeton University + The MINISAT SAT library developed by Niklas Een or Niklas Sorensson.

NuSMV version 2 is distributed with an OpenSource license, namely the GNU Lesser General Public License (LGPL). The aim is to provide a publicly available state-of-the-art symbolic model checker. With the OpenSource development model, a whole community participates in the development of a software systems, with a distributed team and independent peer review. This may result in a rapid system evolution, and in increased software quality and reliability: for instance, the OpenSource model has boosted the take-up of notable software systems, such as Linux and Apache. With the NuSMV OpenSource project, we would like to reach the same goals within the model checking community, opening the development of NuSMV.

You can find further details on NuSMV 2 and on the NuSMV project in paper:

A. Cimatti, E. Clarke, E. Giunchiglia, F. Giunchiglia, M. Pistore, M. Roveri, R. Sebastiani, and A. Tacchella. "NuSMV 2: An OpenSource Tool for Symbolic Model Checking". In Proc. CAV'02, LNCS. Springer Verlag, 2002.

Copyright

NuSMV version 2 (NuSMV 2 in short) is licensed under the GNU Lesser General Public License (LGPL in short). A copy of LGPL-2.1 can be found at url <http://www.gnu.org/licenses/lgpl.txt>.

The aim of the NuSMV OpenSource project is to allow anybody interested to participate to the development of NuSMV. To this purpose, we have chosen a license that:

  1. permits to use the system in research and commercial applications, without restrictions;
  2. is "copyleft", that is, it requires that anyone who improves the system has to make the improvements freely available.

In brief, the LGPL license allows anyone to freely download, copy, use, modify, and redistribute NuSMV 2, proviso that any modification and/or extension to the library is made publicly available under the terms of LGPL.

The license also allows the usage of the NuSMV 2 as part of a larger software system without being obliged to distributing the whole software under LGPL. Also in this case, the modification to NuSMV 2 (not to the larger software) should be made available under LGPL.

Notice that zchaff is for non-commercial purposes only. NO COMMERCIAL USE OF ZCHAFF IS ALLOWED WITHOUT WRITTEN PERMISSION FROM PRINCETON UNIVERSITY. Please contact Sharad Malik (malik@ee.princeton.edu) for details.

Notice also that the CUDD library is copyright University of Colorado. The CUDD library is not covered by LGPL.

Please contact <nusmv@list.fbk.eu> if you have any doubt or comment on the license.

Partners

Different partners have participated to the initial release of NuSMV 2. Every source file in the NuSMV 2 distribution contains a header that acknowledges the developers and the copyright holders for the file. In particular:

  • CMU and ITC-IRST contributed the source code of NuSMV version 1;
  • ITC-IRST has also developed several extensions for NuSMV 2;
  • ITC-IRST and the University of Trento have developed the SAT-based Bounded Model Checking package of NuSMV 2;
  • the University of Genova has contributed SIM, a state-of-the-art SAT solver, and the RBC package used in the Bounded Model Checking algorithms.
  • FBK-irst has developed version 2.5.0 and later.

The NuSMV team has also received several contributions for different part of the system. In particular:

  • Ariel Fuxman <afuxman@cs.toronto.edu> has extended the LTL to SMV tableau translator to the past fragment of LTL
  • Rik Eshuis <eshuis@cs.utwente.nl> has contributed a strong fairness model checking algorithm for LTL specifications
  • Dan Sheridan <dan.sheridan@contact.org.uk> has contributed several extensions and enhancements to the Bounded Model Checking algorithms.

Statements of interest have also come from several other commercial and academic institutions.

Mailing Lists

Refer to this page.

Bug Reports

We have performed an extensive test activity on NuSMV2. Still, NuSMV is large software system and contains many interacting features.

If you find a bug or misbehavior, please let us know, so that we can fix it for the next releases of NuSMV.

You can send an email to <nusmv-users@list.fbk.eu> with the description of the bug. Refer to this page for more information.

NuSMV Staff <>
https://nusmv.fbk.eu/