Mathlib is a user maintained library for the Lean theorem prover. It contains both programming infrastructure and mathematics, as well as tactics that use the former and allow to develop the later.

You can find detailed instructions to install Lean, mathlib, and supporting tools:

• On Debian-derived Linux (Debian, Ubuntu, LMDE...)
• On other Linux distributions
• On MacOS
• On Windows

Got everything installed? Why not start with the tutorial project?

For more pointers, see Lean Links.

Besides the installation guides above and Lean's general documentation, the documentation of mathlib consists of:

• The mathlib docs: documentation generated automatically from the source .lean files. In addition to the pages generated for each file in the library, the docs also include pages on:
  • tactics,
  • commands,
  • hole commands, and
  • attributes.
• A description of currently covered theories, as well as an overview for mathematicians.
• A couple of tutorials
• Some extra Lean documentation not specific to mathlib
• Documentation for people who would like to contribute to mathlib

Much of the discussion surrounding mathlib occurs in a Zulip chat room. Since this chatroom is only visible to registered users, we provide an openly accessible archive of the public discussions. This is useful for quick reference; for a better browsing interface, and to participate in the discussions, we strongly suggest joining the chat. Questions from users at all levels of expertise are welcomed.

• Jeremy Avigad (@avigad): analysis
• Reid Barton (@rwbarton): category theory, topology
• Mario Carneiro (@digama0): all (lead maintainer)
• Bryan Gin-ge Chen (@bryangingechen): documentation, infrastructure
• Johan Commelin (@jcommelin): algebra
• Floris van Doorn (@fpvandoorn): all
• Gabriel Ebner (@gebner): all
• Sébastien Gouëzel (@sgouezel): topology, calculus
• Simon Hudon (@cipher1024): all
• Chris Hughes (@ChrisHughes24): group theory, ring theory, field theory
• Yury G. Kudryashov (@urkud): analysis, topology
• Robert Y. Lewis (@robertylewis): all
• Patrick Massot (@patrickmassot): documentation, topology
• Scott Morrison (@semorrison): category theory