What is Isabelle?
Isabelle is a generic proof assistant. It allows mathematical formulas to be expressed in a formal language and provides tools for proving those formulas in a logical calculus. Isabelle was originally developed at the University of Cambridge and Technische Universität München, but now includes numerous contributions from institutions and individuals worldwide. See the Isabelle overview for a brief introduction.
Now available: (October 2022)
Hardware requirements:
- Small experiments: 4 GB memory, 2 CPU cores
- Medium applications: 8 GB memory, 4 CPU cores
- Large projects: 16 GB memory, 8 CPU cores
- Extra-large projects: 64 GB memory, 16 CPU cores
Some notable changes:
- HTML presentation is more robust and covers more files and links.
- Display of instantiation for schematic goals.
- PIDE: improved Isabelle/VSCode based on bundled VSCodium engine.
- HOL: various improvements of theory libraries.
- HOL: updates and improvements of Sledgehammer.
- HOL: improved simproc support for record types.
- ML: scalable type Bytes.T with support for XZ compression.
- System: bundled Node.js/Chromium/Electron platform (via VSCodium).
- System: Isabelle/Scala is based on Scala 3 (dotty compiler).
- System: tools to sync hg repositories, notably Isabelle + AFP.
- System: improved "isabelle log" tool with regex filtering. +
- System: more robust SSH support in Isabelle/Scala. +
See also the cumulative NEWS.
Distribution & Support
Isabelle is distributed for free under a conglomerate of open-source licenses, but the main code-base is subject to BSD-style regulations. The application bundles include source and binary packages and documentation, see the detailed installation instructions. A vast collection of Isabelle examples and applications is available from the Archive of Formal Proofs.
Support is available by the official documentation and mailing lists:
- isabelle-users@cl.cam.ac.uk provides a forum for Isabelle users to discuss problems, exchange information, and make announcements. Users of official Isabelle releases should subscribe or see the archive.
- isabelle-dev@in.tum.de covers the Isabelle development process, including intermediate repository versions, and administrative issues concerning the website or testing infrastructure. Early adopters of development snapshots or repository versions should subscribe or see the archive.
Zulip Chat is a real-time discussion platform to exchange ideas, ask questions, and collaborate on Isabelle projects, with minimalistic public archive.
Stack Overflow is a question-and-answer platform, with complex review process but limited discussion facilities.