GNU Aris

GNU Aris is a logical proof program that supports propositional and predicate logic, as well as Boolean algebra and arithmetical logic, in the form of abstract sequences. Aris uses a predefined set of inference and equivalence rules, but allows the user to reference older proofs, including proofs done in Isar. Aris uses standard logical symbols, and a natural deduction interface, making it easy for beginners to work with.

Downloading Aris

Aris can be found on the main GNU ftp server: (via HTTP) and (via FTP). It can also be found on the GNU mirrors; please use a mirror if possible.


Documentation for Aris is available online, as is documentation for most GNU software. You may also find more information about Aris by running info aris or man aris, or by looking at /usr/share/doc/aris/, /usr/local/doc/aris/, or similar directories on your system. A brief summary is available by running aris --help.

Mailing lists

Aris has the following mailing lists:

Announcements about Aris and most other GNU software are made on info-gnu (archive).

Security reports that should not be made immediately public can be sent directly to the maintainer. If there is no response to an urgent issue, you can escalate to the general security mailing list for advice.

Getting involved

Development of Aris, and GNU in general, is a volunteer effort, and you can contribute. For information, please read How to help GNU. If you'd like to get involved, it's a good idea to join the discussion mailing list (see above).

Test releases
Trying the latest test release (when available) is always appreciated. Test releases of Aris can be found at (via HTTP) and (via FTP).
For development sources, issue trackers, and other information, please see the Aris project page at
Translating Aris
To translate Aris's messages into other languages, please see the Translation Project page for Aris. If you have a new translation of the message strings, or updates to the existing strings, please have the changes made in this repository. Only translations from this site will be incorporated into Aris. For more information, see the Translation Project.
Aris is currently being maintained by Ian Dunn. Please use the mailing lists for contact.


Aris is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3 of the License, or (at your option) any later version.