NuSMV vs Why3
NuSMV
nusmv.fbk.euWhy3
why3.orgSide by side
| Figure | NuSMV | Why3 |
|---|---|---|
| Price from | Free | Free |
| Free plan | Yes | Yes |
| Free trial | — | — |
| Open source | — | — |
| Web | — | Yes |
| Windows | Yes | Yes |
| macOS | Yes | — |
| Linux | Yes | Yes |
| API | — | Yes |
| Self-hosted | — | Yes |
| Plans published | 1 | 1 |
| Spec score · Formal Verification Tools | 7.7 (#18) | 8.0 (#12) |
| Integrations | NuSMV2's SAT based component can connect to the Minisat SAT solver, and the project describes cooperation to integrate NuSMV into ICS's SCL Visual Modeler. | The project lists EasyCrypt, Frama-C, and SPARK 2014 among projects that use Why3. |
| License | NuSMV v2 is open source software distributed under the LGPL v2.1 license. | TryWhy3 is distributed under the GNU Lesser General Public License version 2.1 with a special linking exception. |
| Purpose | NuSMV is a software tool for formally verifying finite state systems. | Why3 is a platform for deductive program verification that uses WhyML and external theorem provers to discharge verification conditions. |
| Support | The project directs general questions and bug reports to its users mailing list and provides a separate list for announcements. | The project provides a user mailing list, a Zulip chat, and a bug tracking system. |
Plans
In their own words
NuSMV
NuSMV is a self-hosted software tool for formally verifying finite state systems. It checks systems against CTL specifications and supports LTL and PSL model checking. NuSMV 2 combines BDD-based model checking with SAT-based bounded model checking. Its SMV input language supports hierarchical descriptions, reusable components and finite data types, including booleans, scalars, bit vectors and fixed arrays. Other capabilities include an interactive text shell, invariant analysis and partitioning methods; the SAT component can connect to the Minisat solver. The project describes uses in industrial design verification, custom verification tools and research into formal verification techniques. NuSMV runs on Linux, macOS and Windows, and version 2 is open source under LGPL v2.1. The project directs general questions and bug reports to its users mailing list, with a separate list for announcements. Its FAQ says there is no current tutorial for developers extending the tool. It also warns that processes are deprecated because they can behave incorrectly with relational constructs such as TRANS, INIT or INVAR.
Why3
Why3 is a platform for deductive program verification. It uses WhyML to express programs and specifications, then works with external automated or interactive theorem provers to discharge verification conditions. WhyML supports preconditions, postconditions, assertions, and loop invariants, alongside logical theories and data structures such as arrays, queues, and hash tables. External provers need to be installed and configured separately. Why3 can be extended with support for new provers and used as a software library through its OCaml API. WhyML programs can be extracted automatically into correct-by-construction OCaml programs, and WhyML is also used as an intermediate language for verification of C, Java, Rust, and Ada. TryWhy3 provides a JavaScript version that runs in a browser. Installation options include Opam, Docker, source compilation, and listed Debian, Fedora, and Ubuntu packages. Its graphical interface saves proof attempts and transformations in an XML file and can replay obsolete attempts. Why3 is free and open source under GNU LGPL 2.1 with a special linking exception. Loop invariant inference is a work in progress, and many features remain very limited.