Announcing Kind 2 1.9.0

[kind2-announce]

Dear all,

We are happy to announce the new official release (v1.9.0) of Kind 2,
an open-source, multi-engine, SMT-based automatic model checker for
safety properties of Lustre programs [1].

In addition to several improvements and bug fixes, this release includes
the following new functionalities:

- Support for 'elsif' clauses in If-Then-Else constraints.
- Dedicated syntax for reachability properties of the form:
  - check reachable P [from <int>] [within <int>]
  - check reachable P at <int>
  The modifiers 'from', 'within' and 'at' allow users to specify
  a lower and upper bound on the number of execution steps
  in the witness trace.
- Dedicated syntax for conditional properties of the form:
  - check A provided B
- Non-vacuity checks for conditional properties and
  contract mode implications.

Please refer to the CHANGES document [2] for a more detailed
description, and to the user's documentation [3] for further details.

The latest version of Kind 2 can be downloaded from
https://github.com/kind2-mc/kind2/releases and is distributed in
source form, as well as binaries for both Linux and macOS.
It can also be installed through OPAM.

Feedback and feature requests are most welcome. Please contact the
developers or open an issue directly on Github at
https://github.com/kind2-mc/kind2/issues/new

If you want to participate in discussions with developers and other
users of Kind 2, you are encouraged to join the kind2-users group at
https://groups.google.com/d/forum/kind2-users

Best,

The Kind 2 Development Team

[1] http://kind.cs.uiowa.edu
[2] https://github.com/kind2-mc/kind2/blob/v1.9.0/CHANGES.md
[3] https://kind.cs.uiowa.edu/kind2_user_doc/