This is the repository for Lean 4, which is being actively developed and published as nightly releases. Stable point releases are planned for a later date after establishing a robust release process.

About

• Quickstart
• Walkthrough installation video
• Quick tour video
• Homepage
• Theorem Proving Tutorial
• Functional Programming in Lean
• Manual
• Release notes starting at v4.0.0-m3
• Examples
• External Contribution Guidelines
• FAQ

Installation

See Setting Up Lean.

Contributing

Please read our Contribution Guidelines first.

Building from Source

See Building Lean.