Anthropic says Fable 5 reproduced 5 of OpenAI’s 10 Astra math advances in 24 hours

EricBuess · x · 2026-08-04

Anthropic’s Fable 5 reportedly reproduced half of OpenAI’s ten Astra math advances in 24 hours

Anthropic mathematician Levent Alpöge says Fable 5 autonomously solved five of the ten Astra math results within a day, using only a generic prompt and no internet access.

The post argues that these breakthroughs may not hinge on a single secret model or carefully tuned prompt. It also notes that the results still need to be published and independently verified, but suggests research-level math may be turning into a repeatable frontier capability rather than a one-off milestone.

Related event: Anthropic Employee Reproduces Half of Astra Math Proofs Using Fable in 24 Hours(4 posts)→

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