Checked fact 446110 Nov 2026Research

The post says the formalization was in the mathematical programming language Lean.

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The exact words it rests on

Lean

What the source said when we opened it, on 10 Nov 2026.

The source

Claude Fable 5.2 and Claude Mythos 5.2
Anthropic · 2026-11-09

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Checked

Checked by the notis newsroom on 10 Nov 2026, against the source above.

In the story

Anthropic says 1,000 Fable 5.2 agents formalized Fermat's Last Theorem in Lean in 30 hours; the post names no checker. 10 Nov 2026

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The company says: “The post says the formalization was in the mathematical programming language Lean.” ai notis, checked 10 Nov 2026. Source: Claude Fable 5.2 and Claude Mythos 5.2 (Anthropic). https://ainotis.com/c/4461

As a reference (APA style)

ai notis. (2026, November 10). The company says: The post says the formalization was in the mathematical programming language Lean [Checked claim 4461]. ai notis. https://ainotis.com/c/4461

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