Research with GPT-6.1 Sol

Official summary of the Intelligence Index result, with pricing and cache-read changes.

Short proofs for six Graffiti conjectures (198, 219, 252, 254, 584 and 712) written with Opus 5.5 and GPT-6.1 Sol.

Dataset and scorecard from 3,527 calls across seven tracks comparing Sol 6.1 with GPT-6 Sol, Astra, Luna and GPT-5.6 Sol, with per-item results.