Lean formalization in OpenAI math repository (Result 327)
Model / AI: OpenAI (unreleased)
OpenAI's internal frontier model proved and formalized in Lean the main result of 'Nontrivial Markov Type Forces Superreflexivity'. We prove that every real Banach space with Markov type p > 1 is superreflexive. Together with the known converse, this characterizes superreflexivity by nontrivial Markov type. This answers Naor's question: every real Banach space with nontrivial Markov type admits an equivalent uniformly smooth norm.
Source read 2026-10-08. Cataloged from OpenAI's formalization.yaml (Family 327). The Lean development was not rebuilt locally.