Installing Lean and mathlib 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, curl, and python3 (on Debian and Ubuntu also python3-pip and python3-venv). 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. The alternative is to use Emacs, and its lean-mode.
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 lean extension (unique name jroesch.lean). There is also a lean4 extension, but that one does not work with mathlib.
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.
Then we install a small tool called leanproject that which will handle updating mathlib according to the needs of your current project. We use pipx to perform the installation.
```
python3 -m pip install --user pipx
python3 -m pipx ensurepath
source ~/.profile
pipx install mathlibtools
```

Lean Projects #

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