Cleo, the mathematician that tricked Stack Exchange

10 months ago

Cleo was an anonymous mathematician active on Stack Exchange from 2013 to 2015, known for solving complex integrals without showing steps.
Cleo posted 39 answers, often correct and quick, but controversial for lacking explanations, sparking debates about identity and methods.
Speculations about Cleo's identity included famous mathematicians or AI, but in 2025, Cleo was revealed to be Vladimir Reshetnikov, a software developer.
Reshetnikov created Cleo to generate interest in overlooked mathematical problems, using mystery to encourage others to solve them.
Cleo's first notable answer in 2013 solved a difficult integral correctly, later validated by another user with a detailed proof.
The Math.SE community had mixed reactions to Cleo's answers, valuing correctness but criticizing the lack of educational explanations.
Reshetnikov's identity was uncovered through email recovery links connecting Cleo to his other accounts, confirmed by encoded messages.

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