Bubeck says GPT-5.6 matches humans on a self-contracted curve bound

Sebastien Bubeck reports that GPT-5.6-pro reproduced the 2^n lower bound and reached a 2.31^n upper bound on self-contracted gradient flow curve length. He compares these results with prior human work, where the best known upper bound is 2.29^n, and suggests the question may stop being useful for tracking AI progress within about six months.