Cleo, the Mathematician Who Solved Impossible Integrals Without Proof, Was a Microsoft Developer
Cleo (Mathematician)
For years, the Math Stack Exchange user 'Cleo' stunned mathematicians by posting flawless solutions to complex integrals without any explanation. In January 2025, Cleo was revealed to be Vladimir Reshetnikov, an Uzbek-American software developer. He created the persona to spark interest in neglected problems, but his terse answers ignited a debate about the value of results without proofs.
I was frustrated that when I posted questions about integrals on Math.SE, I often received comments like 'Why is this interesting?' or 'What makes you think that it may have a closed-form solution?'
- DavidSJ
The page states:
In late 2023, a Reddit user known as "evilscientist311" conducted a comprehensive analysis of Cleo's activity patterns and interactions with other Stack Exchange accounts.
However, I and others were on the scent at least as far back as April, 2023. See for example: https://x.com/TheDavidSJ/status/1650957407902658571
- snailmailman
I think there are some interesting parallels between what the Cleo account did, and what the large AI companies are doing now with some of the proofs for previously unsolved theorems.
There may be some value in the answers, but for some the value is in the understanding of how to get from the problem to the solution.
I wouldn't call myself a mathematician, but I encountered a few problems in my CS classes where I could work through the proof by hand, see that an algorithm works, and even mathematically prove it, but yet still didn't feel like I understood why it worked, or how the algorithm was invented/derived. But for many, the fact that it did work was enough.
- epcoa
Were any of the 39 answers to a question that was not likely to be from a sock puppet?
Doesn’t necessarily make the solutions less impressive, but it’s kind of a relevant detail that is left out in the Wikipedia summary.
- kylepomykala
They found out who he was? That's amazing.
- agnishom
Granted this is an interesting curiosity, but Cleo hardly qualifies as a mathematician.
Also, didn't Cleo post the problems themselves?