Astra’s Lean proof refutes Smale’s K=1 mean-value conjecture

Astra proved in Lean that a complex polynomial p exists with p(0)=0 and p′(0)=1 such that |p(c)/c|>1 at every critical point c. Thus the universal K=1 mean-value inequality fails at z=0.

Sources for this record

What was already known

Smale proved the inequality with constant 4 and asked whether 1 suffices. Restricted classes and low degrees had positive results.

AI involvement AI-autonomous

GPT-6 Astra found the construction and Lean proof in an unsteered Epoch AI evaluation. Tom Adamczewski ran the evaluation; later human work explained and strengthened the result.

The evaluation record documents an unsteered Astra proof search and formal counterexample.

Importance Notable

The formal witness answers the long-standing K=1 question negatively.

Limitations

The original witness has large unspecified degree and a small violation. Jatar and Ng’s later stronger numerical lower bound is separate human work; they explain but do not report checking Astra’s Lean proof line by line.

Technical verification Formal (Lean 4 with Comparator)

Lean and Comparator reportedly check the negated K=1 statement and its correspondence to the benchmark.

Formal checking

Kernel type checking, trusted-statement comparison and axiom audit

Checker
Lean 4 kernel and Comparator, reported by Adamczewski; VibeMathed audited the statement
Scope
Negation of MeanValueProblem.mean_value_problem, witnessed at z=0 with p′(0)=1
Basis
Reported by the linked checker
Evidence source

Checking a formal statement does not establish that it matches the original problem.

Human understanding Full

Jatar and Ng explain the four main steps of Astra’s construction.

Correction and publication history

2026-10-18 · publication

The AI-found K=1 counterexample is one claim across two catalog listings; later quantitative human bounds remain separate.

Read this published revision