Collaborative Analysis Formalisation seminar

For the course at Bonn SuSe 24.


Note: To get this repository, you will need to download Lean's mathematical library, which takes about 5 GB of storage space.

  • You have to install Lean, and two supporting programs: Git and VSCode. Follow these instructions to do this. You do not have to follow the last step (creating Lean projects). Instead, use either VSCode or a terminal to get this repository.

Get the Repository using VSCode

  • Open Visual Studio Code

  • Press Clone Git Repository (if you don't see the welcome screen, you can press ctrl+shift+P (or cmd+shift+P on Mac), type Git: Clone and press enter)

  • Type and press enter 1

  • Choose a folder where you want to clone this repository (everything will be placed in a subfolder BonnAnalysis).

  • Press open when asked if you want to open the cloned repository

  • Open the file BonnAnalysis/Test.lean using the explorer button in the top-right. Do not press Restart Lean or Rebuild Imports when these pop-ups show up. (If you do, you will rebuild mathlib yourself, which is not recommended)


  • In the top-middle (or top-right) of the screen there is a Lean menu marked by . In it, choose Project Actions... > Project: Fetch Mathlib Build Cache. This downloads mathlib, and will take a bit of time.


  • Once this is finished, press the Rebuild Imports button. The file should be ready a few seconds later. If you see a blue squiggle under #eval, Lean is running correctly.

Get the Repository using a terminal

  • Open a terminal (I recommend git bash on Windows, which was installed as part of git in the first step).

  • Use cd to navigate to a directory where you would like to create the BonnAnalysis folder.

  • Run git clone

  • Run cd BonnAnalysis

  • Run lake exe cache get!

    • This downloads mathlib, and will take a bit of time
    • On Windows, if you get an error that starts with curl: (35) schannel: next InitializeSecurityContext failed it is probably your antivirus program that doesn't like that we're downloading many files. The easiest solution is to temporarily disable your antivirus program.
  • Launch VS Code, either through your application menu or by typing code . (note the dot!). (MacOS users need to take a one-off extra step to be able to launch VS Code from the command line.)

  • If you launched VS Code from a menu, on the main screen, or in the File menu, click "Open folder" (just "Open" on a Mac), and choose the folder BonnAnalysis (not one of its subfolders).

  • Test that everything is working by opening BonnAnalysis/Test.lean. It is normal if it takes 10-60 seconds for Lean to start up.

Building the blueprint

To test the Blueprint locally, you can compile print.tex using XeLaTeX (i.e. xelatex print.tex in the folder blueprint/src). If you have the Python package invoke you can also run inv bp which puts the output in blueprint/print/print.pdf. If you feel adventurous and want to build the web version of the blueprint locally, you need to install some packages by following the instructions here. But if the pdf builds locally, you can just make a pull request and use the online blueprint.

Making a pull request

  • Update this repository to the latest version (run git pull or git fetch + git merge or their equivalents using VSCode source control).

  • Switch to a branch. You can create a new branch using git switch -c mynewbranch or use ... > Checkout to > Create new branch in VSCode. (This can also be done after the next step if you forget.)

  • Write some Lean code

  • Push your branch to your fork of this repository

    • Using the terminal you first have to create a fork on Github and use git remote add to add this fork
    • Using VSCode this fork automatically created for you
    • When you have added a new file, please import it in BonnAnalysis.lean.
  • Open a pull request

    • Just after you push this page will have a message on the top prompting you to open a pull request.
  • If it builds, I'll merge it.

    • Feel free to make a pull request with partial work and a lot of sorry's, as long as it builds.

Reminder: Some additional details can be found in the instructions of the LeanCourse repository: