Installing Lean 4 on Linux #

This document explains how to get started with Lean and mathlib on a generic Linux distribution (there is a specific page for Debian and derived distributions such as Ubuntu).

All commands below should be typed inside a terminal.

• Lean itself doesn't depend on much infrastructure, but supporting tools needed by most users require git and curl. So the first step is to get those.

• The next step installs a small tool called elan which will handle updating Lean according to the needs of your current project (hit Enter when a question is asked). It will live in $HOME/.elan and add a line to $HOME/.profile.

  curl https://raw.githubusercontent.com/leanprover/elan/master/elan-init.sh -sSf | sh
  

• You will also need a code editor that has a Lean plugin. The recommended choice is Visual Studio Code which currently has the best Lean support. The alternatives are to use Emacs and its lean-mode or neovim and its lean.nvim extension.

  1. Install VS Code.
  2. Launch VS Code.
  3. Click on the extension icon (or in older versions) in the side bar on the left edge of the screen (or press ShiftCtrlX) and search for leanprover.
  4. Select the lean4 extension (unique name leanprover.lean4).
  5. Click "install" (In old versions of VS Code, you might need to click "reload" afterwards)
  6. Verify Lean is working, for example by saving a file test.lean and entering #eval 1+1. A green line should appear underneath #eval 1+1, and hovering the mouse over it you should see 2 displayed.

Lean Projects #

You can now read instructions about creating and working on Lean projects