Jannis Limperg

Hi! I'm Jannis Limperg, a PhD student of computer science on the Lean Forward project under the supervision of Jasmin Blanchette.

I'm interested in interactive theorem proving, particularly tooling and proof automation for theorem provers based on dependent type theory. I currently use Lean 4 and have previously used Coq and Agda.

Publications

• Aesop: White-Box Best-First Proof Search for Lean
  Jannis Limperg and Asta Halkjær From. CPP 2023. Distinguished Paper Award
  Published PDF ∎ Publisher's website ∎ Supplement ∎ Slides
• A Novice-Friendly Induction Tactic for Lean
  Jannis Limperg. CPP 2021
  Published PDF ∎ Publisher's website ∎ Supplement ∎ Short talk + slides ∎ Long talk + slides

Theses

• A Reflexive Graph Model of Sized Types
  Chalmers University of Technology. 2019. Supervised by Andreas Abel
  PDF ∎ Code ∎ Rendered code
• A Cofixpoint Combinator for Mixed Recursive-Corecursive Functions
  University of Freiburg. 2017. Supervised by Peter Thiemann
  PDF ∎ Code

Software

• Aesop: white-box proof automation for the Lean 4 theorem prover

Talks

• Towards Complete Tree-Based Proof Search with Metavariables
  With Asta Halkjær From. VU Theoretical Computer Science Seminar. May 2022
  Slides
• Towards General-Purpose Automation for Lean
  Lean Together 2021
  Video ∎ Slides

Academic Service

• Artifact Evaluation Co-Chair, ICFP 2022 and 2023
• Member of the IPA PhD Council, 2022—
• Artifact Evaluator, ICFP 2021
• Subreviewer, CAV 2021 and AITP 2021

Teaching

• Logical Verification 2020—2022 (TA and some lectures)
• Logic and Modelling 2022 (TA and some lectures)

Students

• Othman Alhorani. Implementing and Verifying Merge Sort in Lean 3. BSc thesis. 2021
• Péter Kementzey. A Graph Library for Lean 4. BSc thesis. 2021
• Sofia Konovalova. Verifying AVL Trees in Lean. BSc thesis. 2021

Blog

• A Guide to GHC's Extensions

• A Basic Lean 4 Project Template 31 May 2021
• Some Lean Metaprogramming Gotchas 19 August 2020
• On the Master Programme "Algorithms, Languages and Logic" at Chalmers University Gothenburg 27 December 2019
• Yoneda's Lemma in Excruciating Detail 27 July 2018

Contact

• E-Mail: <my first name>@<my last name>.de or j.b.<my last name>@vu.nl
• PGP key: 19A1F1FCF8652F1EDF460E5D4723F9AD5B3835B9
• GitHub: JLimperg
• Reddit: /u/jlimperg