FrontierMath Tier 4 fully solved: GPT-6 Astra cracks the last problem standing

Jsevillamol · x · 2026-09-11

Epoch AI reports that every FrontierMath Tier 4 problem has now been solved by AI, with GPT-6 Astra solving the last one, authored by Jay Pantone. The benchmark's designer adds: the set was built in the o4-mini era with a slow solve rate expected; his January prediction of saturation within nine months proved accurate despite some invalidated problems.

His takeaway: our understanding of what is truly hard in mathematics needs a complete rethink.

Related event: GPT-6 Astra Solves Final Problem, FrontierMath Tier 4 Fully Saturated(5 posts)→

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