Documentation A comprehensive tutorial on Abella has been published in the Journal of Formalized Reasoning. This is the best reference for starting from scratch.

New users are encouraged to read the walkthrough of an example Abella session.

After the first walkthrough, users are encouraged to continue with the advanced walkthrough.

NEW! A tutorial on schematic polymorphism is available for version 2.0.6 onwards.

A tutorial on schematic polymorphism is available for version 2.0.6 onwards. After both walkthroughs, users should be ready to understand any of the examples included in the distribution of Abella.

The Abella reference guide has a brief description of syntax, commands, and tactics.

The Abella mailing list is open for questions and discussions.

Support Abella is under active development.

For bug reports and feature requests, please use the issues tracker on the official repository.

For other kinds of feedback, for inquiries about support, and for discussions about the use and development of Abella, please use the Abella mailing list.

Contributors The original Abella system was designed and implemented by Andrew Gacek, who also developed its logical foundations in collaboration with Dale Miller and Gopalan Nadathur.

The extension of Abella to include a richer specification logic starting from version 2.0.0 was carried out by Yuting Wang (UMN) and Kaustuv Chaudhuri (INRIA).

A number of people have contributed to the design and the library of examples in Abella. The following are some of the main contributors, listed in alphabetical order. David Baelde (ENS Cachan) Dale Miller (INRIA and LIX/Ecole Polytechnique) Gopalan Nadathur (UMN) Alwen Tiu (ANU) Todd Wilson (CSU Fresno)



History The Abella system represents a collaboration between a group at the University of Minnesota led by Gopalan Nadathur and the Parsifal team at INRIA Saclay – Île-de-France and LIX/Ecole Polytechnique led by Dale Miller. Work on Abella began as part of an NSF-funded project at the University of Minnesota aimed at developing flexible frameworks for specifying, prototyping and reasoning about computational processes. Gopalan Nadathur provided guidance in the design of that version of Abella and he and Dale Miller contributed to the specific logic that Abella is based on. The recent extension of Abella to support a richer specification logic has been the result of a transatlantic collaboration supported by the Recent Advances in Proof Theory (RAPT) Associated Team, led by Kaustuv Chaudhuri (INRIA, France); international participants of this team include a group at McGill University (Canada) led by Brigitte Pientka and a group at the University of Minnesota (USA) led by Gopalan Nadathur. Work on this extension at the University of Minnesota has been supported by the NSF under the grants CCF-0917140 and OISE-1045885. As a part of this effort, Yuting Wang designed and implemented the extension to higher-order hereditary Harrop formulas as the specification language. Subsequent work, carried out by Gopalan Nadathur and Yuting Wang and supported by the NSF Grant CCF-1617771, has resulted in the addition of a form of schematic polymorphism to Abella. The reasoning logic underlying Abella builds on the previous work of several people, most prominently Alwen Tiu, Dale Miller and Raymond McDowell. Work on Abella has benefited from several comments and encouragement provided by Alwen Tiu and David Baelde who have also been amongst the first users of the system. Todd Wilson has created several large developments in Abella and has incorporated its use into some of his graduate courses; his resulting feedback has been invaluable for increasing the usability and robustness of the system.

Funding Work on Abella was funded in its early stages by a grant from Boston Scientific. Subsequent funding has been provided by the National Science Foundation through the Grants CCR-0429572, CCF-0917140, OISE-1045885, and CCF-1617771. The first two NSF grants also included supplementary funding from the OISE for Slimmer, an international collaborative project between the University of Minnesota and the Parsifal group at Ecole Polytechnique and INRIA, France. Support for the French portion of this collaboration has been provided by a sequence of Associated Team grants from INRIA. Opinions, findings, and conclusions or recommendations expressed in this work are those of the authors and do not necessarily reflect the views of the National Science Foundation or the other funding sources.