VerifyThis 2026 will take place as part of the European Joint Conferences on Theory and Practice of Software (ETAPS 2026) on 11 and 12 April 2026. It is the 14th event in the VerifyThis competition series. Information on previous events and participants can be found at https://verifythis.github.io/.
The aims of the competition are:
The competition will offer a number of challenges presented in natural language. Participants have to formalize the requirements, implement a solution, and formally verify the implementation for adherence to the specification. There are no restrictions on the programming language and verification technology used. Solutions will be judged for correctness, completeness and elegance.
To be able to offer a broad and diverse set of verification challenges, we are collecting submissions of ideas for verification challenges and problems. We welcome both problems of academic interest as well as challenges based on themes that are relevant in industry. The competition proceeds in three rounds. In each round, participants are given 60 - 120 minutes to implement and prove specified properties of a given algorithm and/or data structure. They are free to use any verification tools they choose. Challenges are typically concerned with proving functional properties of the code in question (at least some part of a challenge involves expressing and proving properties specific to the algorithm/data structure in question). It is common for problems to have multiple parts, e.g. to prove some basic properties first, perhaps for a simplified case, and to progress to more-advanced goals.
We are looking for problem submissions. If you have recently encountered an interesting challenge in your work where formal techniques could be applied, please don’t hesitate to submit it. Typical challenges have clear input-output specifications and often incorporate one or more of the following: heap allocation, concurrency, arithmetic reasoning. A challenge usually describes a problem using natural language together with some pseudocode, and then provides a list of properties or “verification tasks” of varied levels of difficulty. Contributors are encouraged to look at the Archive of previous problems.
An award will be given for any submission used in the competition. To avoid spoiling the competition for others, we ask that you keep the subject of your submission private. However, note that problem authors are allowed to participate in the competition!
Submissions should be sent by email to s.ayoun17@imperial.ac.uk and thibault.dardinier@inf.ethz.ch. The submission deadline is February 8, 2026. We look forward to receiving your ideas!
Contributors are encouraged to look at the archive of previous problems or here: