[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 . 1 . 0 (July 03, 2002) We are happy to announce the availability of a new version of the NuSMV model checker. NuSMV version 2.1.0 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 2.1 is a major release of NuSMV 2. Several improvements have been done with respect to NuSMV 2.0 (see NEWS below). The most relevant are: - support for past temporal operators and for strong fairness in LTL - possibility to use the ZCHAFF SAT solver with Bounded Model Checking - revision and improvement of the Bounded Model Checking package - a new user manual with a tutorial on the basic functionalities of NuSMV ======== 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 ==== NuSMV 2.1.0 is a major release of NuSMV. Several improvements have been done with respect to NuSMV 2.0. The most relevant are: * New functionalities - Past LTL Now LTL properties can also include *past* temporal operators. Differently from standard temporal operators, that allow to express properties over the future evolution of the FSM, past temporal operators allow to characterize properties of the path that lead to the current situation. Past LTL temporal operators are supported both in BDD-based Model Checking and in Bounded Model Checking of LTL specifications. The extended LTL to SMV tableau translator for the past fragment of LTL has been contributed by Ariel Fuxman . - Full Fairness Now NuSMV supports two types of fairness constraints, namely the weak fairness, or "justice", constraints and the strong fairness, or "compassion", constraints. A justice constraint consists of a formula f which is assumed to be true infinitely often in all the fair paths. A compassion constraint consists of a pair of formulas (p,q); if property p is true infinitely often in a fair path, then also formula q has to be true infinitely often in the fair path. Old versions of NuSMV supports only weak fairness. In the current version of NuSMV, compassion constraints are supported only for BDD-based LTL model checking. The strong fairness model checking algorithm for LTL specifications has been contributed by Rik Eshuis . We plan to add support for compassion constraints also for CTL specifications and in Bounded Model Checking in the next releases of NuSMV. - ZCHAFF SAT solver The new version of NuSMV allows for the usage of the ZCHAFF library as the SAT solver in Bounded Model Checking. ZCHAFF is a very strong state-of-the-art SAT solver developed by Princeton University. ZCHAFF won the SAT 2002 Competition as the Best Complete Solver in both industrial and handmade benchmarks categories. ZCHAFF has also shown a consistent speed-up in the solution of Bounded Model Checking problems. * Architecture Several aspects of the NuSMV architecture have been improved. - We have improved the Conjunctive Partitioning management of transition relations. With respect to old versions of NuSMV, the new code is more modular and easier to extend. - The Bounded Model Checking code has undergone a general revision. In particular: - the file organization of the bmc package has been improved in order to enhance readability and extensibility; - a generic interface to Boolean Expression Managers has been added; it is now possible to replace the current manager of boolean expressions (RBC) with more advance managers (e.g., BED); - a generic interface to SAT solvers has been defined; this makes it easier to add support for new SAT solvers in NuSMV. * Documentation - We have updated the user manual with the new features of NuSMV 2. Moreover, we have added to the manual a tutorial that covers the basic functionalities on NuSMV. * Bug fixes Several bug fixes and minor enhancements have been done. ========= 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/