Checked fact 446410 Nov 2026Research

The post says Opus 5.5, with the same 1,000-agent setup, completed only 26% of the formalization in 18 hours and barely made any more progress after 30.

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barely made any more progress after 30

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

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

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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 Opus 5.5, with the same 1,000-agent setup, completed only 26% of the formalization in 18 hours and barely made any more progress after 30.” ai notis, checked 10 Nov 2026. Source: Claude Fable 5.2 and Claude Mythos 5.2 (Anthropic). https://ainotis.com/c/4464

As a reference (APA style)

ai notis. (2026, November 10). The company says: The post says Opus 5.5, with the same 1,000-agent setup, completed only 26% of the formalization in 18 hours and barely made any more progress after 30 [Checked claim 4464]. ai notis. https://ainotis.com/c/4464

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