Lean 4 in Toulouse

Workgroup to learn Lean 4 @ IMT/LPT Toulouse

View the Project on GitHub gulatiaabhas/leanintoulouse

Hi everyone!

We have started a workgroup to learn Lean language to learn the basics of formalising mathematics, and we invite anyone interested in Toulouse to join this group. This website will be a repository of all the material covered in the workgroup, notes, videos, and lectures. We will also try to make the lean files available for reference. We hope that this will be a weekly thing, and people try to get a hands-on experience with the software. Hope to see you at the next meeting.

Aabhas Gulati and Ion Nechita

Upcoming Meetings

Friday April 11th, 3:15 pm, Salle F. Pellos (1R2-207)

Past Meetings

Friday April 4th, 2:00 pm, Salle F. Pellos (1R2-207)

Thanks to Francois for providing all these proofs.

Friday March 28th, 2:00 pm, Salle F. Pellos (1R2-207)

Homework was to formalise your favourite theorem in Group Theory. The lean file for theorems discussed in this session are available here. Thanks to Francois!

There are a few helpful resources, Groups and Lean and Formalisation of basic group theory in Lean.

Friday March 21st, 3:15pm, Salle F. Pellos (1R2-207)

We discussed the homework and we have updated the file with the proof.

We also discussed proofs of a basic theorem in group theory

Theorem

If there is a group G such that for all $x \in G$, we have $x^2 = 1$, then it implies that the group is Abelian.

The lean file for this theorem can be found here

Friday March 14th, 2pm, Salle F. Pellos (1R2-207)

Lean4 cheatsheet

We went line by line through some simple proofs involving even numbers.

We decided on a homework for next time, following the lemma from this video.

Friday March 7th, 2pm, FERMI seminar room

Introductions and set-up. The main webpage for Lean 4

Installation instructions:

The Natural Number Game is a good place to start when learning the basics of Lean.

We briefly saw the proof of: composition of two surjective functions is surjective lean file