[We apologize if you received multiple copies of this message] N N SSSSS M M V V 2222 NN N S MM MM V V 2 2 N N N S M M M M V V 2 N N N u u SSSSS M M M V V 2 N N N u u S M M V V 2 N NN u u S M M V V 2 N N uuuu SSSSS M M V 222222 V E R S I O N 2 . 4 . 0 (Aug 1, 2006) We are happy to announce the availability of a new version of the NuSMV model checker. NuSMV version 2.4.0 is available from http://nusmv.irst.itc.it 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). NuSMV 2.4.0 is a major release of NuSMV to add several new features, to improve the internal capabilities, and to fix several bugs. ======== OVERVIEW ======== NuSMV is a reimplementation 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 testbed for formal verification techniques. NuSMV version 2 extends NuSMV with new model checking algorithms and techniques. It combines classical BDD-based 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 the SIM SAT library developed by the University of Genova. Optionally, NuSMV can also be used with the ZCHAFF SAT library developed by Princeton University. 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. Further details on NuSMV 2 and on the NuSMV project can be found 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. ==== NEWS ==== This is a major release of NuSMV. Several improvements have been made with respect to NuSMV 2.3: * Functionalities - The NuSMV input language has been extended to support bit vectors (i.e. words), and to allow bitwise logical and arithmetic operations over bit vectors. - Strong typing was introduced, in order to eliminate subtle implicit casting rules that were causing problems. Backward compatibility can be obtained by means of a suitable switch that disables type checking. - The Simple Bounded Model Checking approach [1] was integrated, together with the incremental and complete variant [2]. Thanks to Timo Latvala and Tommi Junttila for their contribution to the integration. - The NuSMV internals have been deeply restructured to provide support for the the dynamic creation and removal of new symbols (variables, constants, defines). This allowed to eliminate critical code within the LTL BDD-based model checking algorithms, and to integrate Simple Bounded Model Checking algorithms. - Reachability analysis is now enabled by default. * User interaction - General improvements . Improved the error messages reporting. Line numbers now corresponds to the real line number within the input file. . Improved the writing of the BDD order file: now it is possible to print the bit level order file. - New commands . check_ltlspec_sbmc : non-incremental algorithm to perform SBMC . check_ltlspec_sbmc_inc : incremental algorithm to perform SBMC . gen_ltlspec_sbmc : generates DIMACS file for SBMC problems . print_fsm_stats : substitutes the deprecated command print_clusterinfo - New system variables . output_word_format : the base used to print bit vector constants (during traces, counterexamples, printing, etc). . backward_compatibility : disables some new features to garantee a better backward compatibility. . type_checking_warning_on : enables the emissions of warnings messages by the type checker. . bmc_sbmc_gf_fg_opt : controls the SBMC optimization on formulae of the form "F G p" or "G F p". - New command line options . -old : disables some new check to garantee backward compatibility. . -old_div_op : enables the old semantics of "/" and "mod" operations (from version 2.3.0) instead of ANSI C semantics. . -df : used to disable the computation of reachable states that is enabled by default in version 2.4.0. - Deprecated and no longer supported features . The command 'print_clusterinfo' is deprecated (see 'print_fsm_stats') . The system variable 'enable_reorder' is no longer available * Installation - A windows installer is provided for Microsoft Windows (TM) users. * Bug fixes - Type checking eliminates several bugs present in previous versions. - Support of dynamic symbols declaration fixes all the known bugs in LTL BDD-based model checking. - Determinization variables are now dynamically declared as state variables (instead of input variables). - "G Sequence" is no longer a parsable PSL property. - Several bug fixes have been applied to the printers of PSL formulae - Command 'flatten_hierarchy' is now implemented as reentrant code. - Fainess conditions are now printed correctly - Several memory leaks and numeric overflows were fixed. - Other minor bugs have been fixed (see details in ChangeLog) ========= 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 . 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 AT 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 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. The NuSMV team has also received several contributions for different part of the system. In particular: * Ariel Fuxman has extended the LTL to SMV tableau translator to the past fragment of LTL * Rik Eshuis has contributed a strong fairness model checking algorithm for LTL specifications * Dan Sheridan 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. ================ GETTING IN TOUCH ================ The home page of the NuSMV project is . For questions, comments, or information on NuSMV, please e-mail to . For getting in touch with the NuSMV development staff, please email to . ============= MAILING LISTS ============= We maintain two mailing lists on NuSMV: * nusmv-users General questions, bugs and bug fixes, possible extensions and user requests on NuSMV can be discussed on this list. * nusmv-announce New releases and other important events for NuSMV will be announced on this list. If you are interested in the usage and in the development of NuSMV, we encourage you to subscribe to these mailing lists, using the form available at url . =========== 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 use the bug report form available at url , or send an email to with the description of the bug. -- NuSMV Staff http://nusmv.irst.itc.it/