Proof Ground 2021 - Call for Problems

Dear Coq enthusiasts,

we are organizing another edition of the proving competition workshop
"Proof Ground", which will take place virtually just before ITP 2021.
Please take noteof our Call for Problems, and spread the word!

Call for Problems

Proof Ground 2021
Interactive Proving Contest
June 28, 2021
Proof Ground 2021

at ITP 2021
Interactive Theorem Proving
June 29 - July 2, 2021, (originally in) Rome, Italy, now fully virtual

This workshop brings together researchers of the ITP community to
compete in a “proving contest”.

While programming contests (e.g. ACM ICPC, International Olympiad in
Informatics) challenge large numbers of participants to solve
algorithmic problems within a short time, we envision proving contests
to entice proof engineers to formally prove small but interesting
problems from mathematics or computer science.

A contest system is currently used for
teaching and hosting proving contests in Coq, Isabelle, and Lean.

Proof Ground 2021 is affiliated with the conference on Interactive
Theorem Proving 2021

As the main conference will happen as virtual conferences due to the
ongoing Covid-19 pandemic, Proof Ground 2021 will also take a purely
virtual format.

The first edition of
the workshop has been held at ITP 2019.
The second edition
was affiliated with IJCAR 2020.

Important Dates

  • Submission deadline: May 30, 2021

  • Workshop and Competition: June 28, 2021

Call for Problems

In order to conduct a stimulating contest we solicit interesting tasks.

A contest typically lasts for two hours and consists of around five
problems with varying difficulty.

A problem:

  • should contain an informal statement of the problem together with a
    template for the formal proof;

  • should come with a reference solution (in any ITP);

  • should be solvable (including formal proof) within 30 minutes;

  • should be easy to state in any proof assistant, without requiring
    too much background library;

  • could be from any part of mathematics, software verification, or
    your daily work with ITPs, and could also be a logic puzzle/riddle;

  • could contain several subproblems which lead to partial points.

Submissions from (potential) competition participants are allowed.

Examples can be found at the current “Proving for Fun” contest system,
e.g. here.

Submissions can be made via email to
wimmers [at] in [dot] tum [dot] de by the date indicated above.


Maximilian P. L. Haslbeck
Simon Wimmer
Tobias Nipkow