descriptive claim
Before starting Lean, the speaker spent a sabbatical year in 2009–2010 formalizing the Feit–Thompson theorem.
Unresolved speaker · Mathematics Just Changed Forever — Kevin Hartnett · 26 Oct 2026
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“Before starting the Lean project, um, I had worked in 2009 and 2010. I spent a sabbatical year working on the, the formalization of the Feit-Thompson theorem.”21:33Report a misattribution
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