Plectis Atlas
Search

↑ and ↓ move, Enter opens, Esc closes.

Beyond the square-root exponent for depth-three circuits

OpenAI groups related papers into a “family”. OpenAI’s catalogue describes this one:

Constructs a single language in deterministic polynomial time whose n-bit membership function requires \(2^{\omega(\sqrt n)}\) total gates in unbounded-fan-in OR–AND–OR circuits, at every sufficiently large input length. This crosses the square-root-exponent threshold for explicit depth-three Boolean circuit lower bounds. (OpenAI’s Lean note)

Lean is a language for mathematical statements and proofs that a computer can verify. The assessments below ask whether those statements express the result OpenAI describes here.

Both independent assessments find that the Lean statements express or imply the whole result described above. Read the assessments

The paper states

Theorem 1.1

In Beyond the Square-Root Exponent for Depth-Three Boolean Circuits, 23 September 2026

Possible match to OpenAI’s description, selected from the papers’ main statements because it shares the most wording. No review confirming the selection is recorded.

There is a language L\subseteq\bits^*, a deterministic Turing machine deciding L, and fixed positive integers C,a such that the machine runs in time at most C(n+1)^a on every input of length n. If f_n is the membership function of L on \bits^n, then

\lim_{n\to\infty}\frac{\log_2 S_3(f_n)}{\sqrt n}=\infty.

Equivalently, for every real A>0, there is an integer N_A such that

S_3(f_n)>2^{A\sqrt n}\qquad\text{for every }n\ge N_A.

No uniformity or bottom fan-in restriction is imposed on the circuits.

Reported proof verification
One Lean statement in the release; two independent groups report that Comparator accepted runs for this file at the version shown here.

Papers

Each paper opens as a reading page in the browser, with the PDF beside it. The statements each paper opens with are on its reading page.

One Lean statement in this family

Lean is a language for mathematical statements and proofs that a computer can verify. The Lean statement below is shown beside its possible paper counterpart, with the reason they were linked.

For a configured theorem, the Comparator program tests whether OpenAI’s separate proof proves the exact Lean statement using only the allowed axioms. Some statement files instead configure definitions for comparison by name and type. Acceptance does not establish that a formal statement means the same thing as the paper’s theorem.

DepthThree

The paper states

Theorem 1.1

In Beyond the Square-Root Exponent for Depth-Three Boolean Circuits, 23 September 2026

There is a language L\subseteq\bits^*, a deterministic Turing machine deciding L, and fixed positive integers C,a such that the machine runs in time at most C(n+1)^a on every input of length n. If f_n is the membership function of L on \bits^n, then

\lim_{n\to\infty}\frac{\log_2 S_3(f_n)}{\sqrt n}=\infty.

Equivalently, for every real A>0, there is an integer N_A such that

S_3(f_n)>2^{A\sqrt n}\qquad\text{for every }n\ge N_A.

No uniformity or bottom fan-in restriction is imposed on the circuits.

The words they share: bottom, circuits, function, runs, time, real, language, sqrt, deciding, turing, machine, input, length, integers, depth, three, fan.

Possible Lean counterpart

Selected from shared wording. No review of whether the statements mean the same thing is recorded.

Depth-three circuit lower bound beyond every square-root constant

DepthThree.lean, the release lists it as a main result.

theorem exists_polynomial_time_language_depth_three_lower_bound :    ∃ (L : List Bool → Bool) (M : FiniteMultiTapeMachine) (C a : ℕ),      0 < C ∧ 0 < a ∧      (∀ w : List Bool, MultiTapeHaltsIn M w (L w) (C * (w.length + 1) ^ a)) ∧      ∀ A : ℝ, 0 < A → ∃ N : ℕ, ∀ n : ℕ, N ≤ n →        ∀ D : Circuit3 (Fin n), D.Computes (fun x => L (List.ofFn x)) →          (2 : ℝ) ^ (A * Real.sqrt (n : ℝ)) < (D.gateCount : ℝ) := by  sorry

This file states the theorem with sorry, a placeholder, in place of its proof. OpenAI supplies a separate proof file. Comparator tests whether that proof proves the statement here.

two independent groups report that Comparator accepted runs for this Lean statement file: cert-machine; MathVet. Who ran the proof-verification program

  • cert-machine records it as “CERTIFIED”.
  • MathVet records it as “comparator-sandboxed-pass”.

Read the complete Lean statement

Other mathematical statements in OpenAI’s Lean library

Atlas found these propositions by scanning the text of the project’s Model.lean file. Each name links to its definition, with any associated statement file beside it. This list does not record running Lean to interpret or verify those definitions.

The source scan also found 1 theorem or lemma declarations whose names contain ‘manuscript’.

Independent comparisons and proof-verification reports

Does the Lean express the advertised result?

MathVet and cert-machine agree on how much of the advertised result the Lean statements express.

MathVet and Carlos Toledo’s cert-machine independently assessed whether this family’s Lean statements express the whole result OpenAI describes in its catalogue. These are assessments of the family as a whole, not of each paper theorem separately.

MathVet finds that the Lean statements express or imply the whole advertised result (their term: “full”).

Their note: None; as the docs say, no fixed exponent n^{1/2+eps} and no unrestricted-depth bound is asserted.

Definitions the group asks readers to compare with the paper: Polynomial time is measured on a hand-rolled FiniteMultiTapeMachine (finite tapes/alphabet/states, Mathlib Turing.Tape, MultiTapeHaltsIn = halts within C*(|w|+1)^a steps), not Mathlib’s TM2ComputableInPolyTime; the circuit class Circuit3 is a custom inductive encoding with free negations/constants (standard)

“full”, in their words: The challenge statements imply the headline claim after unpacking definitions or one routine step.

Their method: An independent, model-assisted, pre-referee reading of each family’s challenge statements against its headline claim under a published rubric (PROTOCOL.md), with its own Comparator runs per challenge.

cert-machine finds that the Lean statements express or imply the whole advertised result (their term: “MATCHES”).

“MATCHES”, in their words: The challenge statements state the headline as OpenAI wrote it.

Their method: Every Comparator challenge re-run on Linux with nanoda switched on, decided by a preregistered rule.

OpenAI’s own note on what its Lean covers

The formalized result gives one polynomial-time Boolean language whose exact depth-three OR–AND–OR circuit size eventually exceeds $2^{A\sqrt n}$ for every fixed $A>0$. The language and its polynomial-time algorithm are fixed before $A$ is chosen, while circuits may vary with the input length. Gates have unrestricted finite fan-in and sharing, with free input negations and constants. The result does not assert a fixed exponent $n^{1/2+\varepsilon}$ or a lower bound for unrestricted depth.

AI-drafted comparisons, with no recorded human review

  • Depth-three circuit lower bound beyond every square-root constant DepthThree

    Unreviewed AI draft: states a paper’s theorem as the paper does. States the main theorem: one polynomial-time language whose depth-three circuit size eventually exceeds 2^{A√n} for every fixed A > 0.

Who ran the proof-verification program?

These groups report running Comparator with the release’s Lean statement files. For a configured theorem, it verifies OpenAI’s separate proof against the exact statement; some files instead configure definitions for comparison by name and type. Each row is the named group’s report. Atlas has not repeated the runs.

These reports do not list the software versions, proof-verification programs, axioms, time or memory in separate fields. Any such details in a report’s prose are reproduced below.

Depth-three circuit lower bound beyond every square-root constant DepthThree

Two reports, all at the release’s recorded version.

Reported byTheir wordTheir accountDateOriginal report
cert-machine“CERTIFIED”Re-run through Comparator with the independent nanoda kernel switched on: Lean’s kernel and nanoda both accept OpenAI’s solution.10 October 2026Original report
MathVet“comparator-sandboxed-pass”Re-run through Comparator in a sandboxed virtual machine: accepted.8 October 2026Original report

What these papers cite in the release, and what cites them

These links come from the papers’ bibliographies. A citation records that one paper cites another; how each cited result is used has not been examined here.

Papers elsewhere in the release that this family’s papers cite

This family’s papers cite no paper elsewhere in the release.

Papers elsewhere in the release that cite this family’s papers

No paper elsewhere in the release cites this family’s papers.

References outside the release

Each paper’s outside references are listed with it on its reading page, where each citation is placed. Every outside work cited in the release: References outside the release

Explain a result, compare statements or propose a correction

Atlas has no contributed explanation for this family yet. You can offer one with a GitHub account. You receive named credit and disclose any AI assistance.

Each button opens a GitHub form with this page and its source version filled in. Opening the form does not reserve the work.

Offer to write an explanationCompare the Lean statement with the paperSuggest a source attributionSuggest a change

What people have said

Commentary on this family by others, dated and credited. It is commentary, not a finding.

  • An unsigned public tier list, the OpenAI Math Tier List, classes it as a proof and rates its significance, if it holds up, as “Career-defining publication”. The page says that nothing on it is verified.

    Author not stated. Source

Questions awaiting review

Each item identifies a statement, definition or report that needs further review. Its link opens a GitHub form with the source version already recorded.

Read the Lean statement against the paper

  • An AI agent drafted an assessment of which part of the paper this Lean statement expresses. No named human review is recorded. Open the form

Identify the theorem the catalogue describes

  • Family 112 The theorem shown was selected from shared wording with OpenAI’s description. Atlas records no review confirming that it is the theorem the description means. Open the form

Address a question raised in an independent assessment

Compare the proposed paper and Lean matches

  • Family 112 Atlas records no review of whether each linked Lean statement and paper theorem mean the same thing. Open the form