Complex square, dual, and rectangular exponent bounds
Lean is a language for mathematical statements and proofs that a computer can verify. This page shows one statement file from OpenAI’s release, possible paper matches and independent reports. The code-like names below identify the definitions or theorems selected by the proof-verification settings.
Theorems selected for verification:OAI.MatrixMultiplication.complex_omega_le_nine_quartersOAI.MatrixMultiplication.complex_alpha_gt_93_div_200OAI.MatrixMultiplication.complex_rectangular_omega_lt_523_div_250
A Lean statement states the theorem and leaves its proof as sorry on purpose. OpenAI’s proof is in a separate solution module, and a program called Comparator checks that proof against this statement.
Definitions needed to read it
Local definitions the statement names, followed through the definitions they name in turn. The match is by name in the source text, so a name reached only through notation can be missed; the full file is below.
inductiveProgram (F Input : Type*) : ℕ → Type _ where | nil : Program F Input 0 | step {r : ℕ} : Program F Input r → Gate F Input (Fin r) → Program F Input (r + 1)
structureMatrixAlgorithm (F : Type*) (a b c : ℕ) where registers : ℕ program : Program F (MatrixInput a b c) registers output : Fin a → Fin c → Fin registers
defcomplexAlpha : ℝ := sSup {k : ℝ | k ∈ Set.Icc 01 ∧ rectangularOmega ℂ k = 2}
Possible paper match, with no recorded review
Atlas selected this possible match by comparing words in the Lean statement with every statement in the family. No review of whether the statements mean the same thing is recorded.
Words of the Lean statement, its names split into words, that also appear in the theorem: exponents, arithmetic, multiplication, matrix, alpha and omega. Found in the paper’s title, which its main theorem states: rectangular and complex.
Statements in Complex Matrix Multiplication Below 2.258 and Rectangular Bounds come first because the release’s name for this Lean statement shares words with that paper’s title.
Theorem 1.1 of Complex Matrix Multiplication Below 2.258 and Rectangular Bounds
Theorem
Over \C, the arithmetic matrix-multiplication exponents satisfy
Over \(\C\), the arithmetic matrix-multiplication exponents satisfy
\[
\omega<\frac{1129}{500}=2.258,\qquad
\alpha>0.465,\qquad w(0.709)<2.092.
\]
Other possible paper matches, closest wording first
Theorem 1.1 of An Upper Bound of 9/4 for the Matrix Multiplication Exponent. Words of the Lean statement, its names split into words, that also appear in the theorem: 9/4, complex, arithmetic, two and omega. Found in the paper’s title, which its main theorem states: exponent, multiplication and matrix.
Corollary 14.1 of Complex Matrix Multiplication Below 2.258 and Rectangular Bounds. Words of the Lean statement, its names split into words, that also appear in the theorem: 709/1000, 523/250, field, two, positive and omega. Shared only with the release’s name for the Lean statement or OpenAI’s note on it: bounds.
Theorem 1.1 of Staggered extraction for exact matrix multiplication over every field. Words of the Lean statement, its names split into words, that also appear in the theorem: exponent, field, arithmetic, multiplication, matrix and omega. Shared only with the release’s name for the Lean statement or OpenAI’s note on it: square.
Corollary 14.2 of Complex Matrix Multiplication Below 2.258 and Rectangular Bounds. Words of the Lean statement, its names split into words, that also appear in the theorem: dual, field and alpha. Shared only with the release’s name for the Lean statement or OpenAI’s note on it: bound.
Proposition 4.9 of Complex Matrix Multiplication Below 2.258 and Rectangular Bounds. Words of the Lean statement, its names split into words, that also appear in the theorem: input, multiplication, matrix and alpha. Shared only with the release’s name for the Lean statement or OpenAI’s note on it: bound.
Theorem 3.2 of Complex Matrix Multiplication Below 2.258 and Rectangular Bounds. Words of the Lean statement, its names split into words, that also appear in the theorem: dimensions, integers, positive and omega.
How Atlas selects possible matches: it compares words in the Lean statement with every statement in the family. It also splits Lean names into words. The release’s label and note receive less weight; a main theorem wins a close match. If the Lean wording yields no clear match, Atlas uses the catalogue description. This selects passages to compare; it does not establish that they mean the same thing.
Reported Comparator runs
two independent groups report that Comparator accepted runs for this Lean statement file: Carlos Toledo’s cert-machine; MathVet. Each group reports its own Comparator run for this statement file. Atlas has not repeated the runs.
For a configured theorem, Comparator tests whether OpenAI’s proof proves the exact Lean statement. Some files instead configure definitions for comparison by name and type. Acceptance does not establish that the statement means the same thing as the paper’s theorem.
Every Comparator challenge re-run on Linux with nanoda switched on, decided by a preregistered rule; every family’s challenge statements read against OpenAI’s headline, clause by clause. Decider: Comparator (leanprover/comparator d03acab1 = tag v4.34.0, built with the release’s toolchain v4.34.1), lean4export 076e8e57, landrun 811cfff5, nanoda_lib 3a240721 — on GitHub’s Linux runners (.github/workflows/openai-math-kernel.yml), one j…
AcceptedTheir term: “CERTIFIED”.
Re-run through Comparator with the independent nanoda kernel switched on: Lean’s kernel and nanoda both accept OpenAI’s solution.
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. Its protocol describes a planned error-rate study; this import does not establish that the study has been completed.
If Comparator is run under this configuration and accepts, the solution proves the configured theorem using only the allowed axioms, and the Lean kernel accepts every step.
This configuration lists no definition holes, so every definition the statement uses is compared as it is written in this file.
Acceptance leaves open whether the Lean statement means the same thing as the paper’s theorem, whether the paper’s other claims are correct, and whether the result is new. Those questions require comparing the definitions and statements, reviewing the paper’s arguments, and reading the earlier literature.
Do family 107’s Lean statements express the advertised result?
These assessments compare all the family’s Lean statements with the whole result OpenAI describes in its catalogue. They do not assess this statement alone. Each group uses its own published rules.
MathVet and cert-machine disagree on how much of the advertised result the Lean statements express.
Finds the whole advertised result stated or impliedTheir term: “full”.
The challenge statements imply the headline claim after unpacking definitions or one routine step. Their record
Their note: ω(C) <= 9/4, α > 0.465 and ω(F) < 2.371054886006746 for every field are stated; 'ω < 2.258 outside finitely many positive characteristics' is not. Exponents are sInf of uniform-constant, non-uniform straight-line program families (standard).
Definitions the group asks readers to compare with the paper: omega F := sInf {τ | AdmissibleExponent F τ} is only meaningful if the set is nonempty and bounded below (true: τ = 3 admissible, and cost ≥ n² forces τ ≥ 2; junk value 0 otherwise); complexAlpha := sSup {k ∈ [0,1] | rectangularOmega ℂ k = 2}; the first-conjunct-only reading of omega_lt_source_constant is padded with a pure numeric inequality 2.371054886006746 < 2.371056
Finds part of it stated, or a narrower or weaker statementTheir term: “NARROWER — UNDECLARED”.
The challenge statements state less than the headline, and OpenAI’s Lean note does not say so. Their record
Their note: 'ω < 2.258 outside finitely many positive characteristics' is not stated for any field of positive characteristic; the characteristic-zero rectangular clause is stated over C only. Both would follow from the C results by standard characteristic-transfer arguments (Schönhage-type), but no challenge states them.
OpenAI’s own note on what this Lean statement covers
“The square bound implies the paper's weaker $2.258$ headline bound.”
An AI agent drafted an interpretation of that note, classifying this statement as “states a paper’s theorem as the paper does”. No human review of the draft is recorded.
Supporting material
The complete Lean statement file
132 lines, copied from release version fd4aeeb. A name defined in this file links to its line; pointing at the name shows its definition.
Declared in this fileOpenAI’s library at fd4aeebOther linked names open the current documentation for Mathlib, Lean’s mathematical library.
Links in the file: 29 to its own declarations, 43 to Mathlib’s documentation. 21 declared names also link to the same declaration in OpenAI’s library. OpenAI uses Mathlib version d13f23b. The linked documentation describes the current version, so names that have since changed may be missing there.
import Mathlibnamespace OAI/-! The three main complex matrix multiplication bounds, checked independently. -/noncomputablesectionopenscoped BigOperatorsnamespace MatrixMultiplication.ArithmeticinductiveGate (F Input Register : Type*) where | constant : F → Gate F Input Register | input : Input → Gate F Input Register | add : Register → Register → Gate F Input Register | sub : Register → Register → Gate F Input Register | mul : Register → Register → Gate F Input Registernamespace Gatevariable {F Input Register : Type*}defeval [Field F] (inputs : Input → F) (registers : Register → F) :Gate F Input Register → F | .constant z => z | .input i => inputs i | .add i j => registers i + registers j | .sub i j => registers i - registers j | .mul i j => registers i * registers jdefcost : Gate F Input Register → ℕ | .constant _ => 0 | .input _ => 0 | .add _ _ => 1 | .sub _ _ => 1 | .mul _ _ => 1end GateinductiveProgram (F Input : Type*) : ℕ → Type _ where | nil : Program F Input 0 | step {r : ℕ} : Program F Input r → Gate F Input (Fin r) → Program F Input (r + 1)namespace Programvariable {F Input : Type*}defeval [Field F] : {r : ℕ} → Program F Input r → (Input → F) → Fin r → F | 0, .nil, _ => Fin.elim0 | _ + 1, .step p g, inputs =>Fin.cases (g.eval inputs (p.eval inputs)) (p.eval inputs)defcost : {r : ℕ} → Program F Input r → ℕ | 0, .nil => 0 | _ + 1, .step p g => p.cost + g.costend ProgramabbrevMatrixInput (a b c : ℕ) := (Fin a × Fin b) ⊕ (Fin b × Fin c)defmatrixInputs {F : Type*} {a b c : ℕ} (A : Matrix (Fin a) (Fin b) F) (B : Matrix (Fin b) (Fin c) F) :MatrixInput a b c → F | .inl (i, j) => A i j | .inr (j, k) => B j kstructureMatrixAlgorithm (F : Type*) (a b c : ℕ) whereregisters : ℕprogram : Program F (MatrixInput a b c) registersoutput : Fin a → Fin c → Fin registersnamespace MatrixAlgorithmvariable {F : Type*} [Field F] {a b c : ℕ}defeval (P : MatrixAlgorithm F a b c) (A : Matrix (Fin a) (Fin b) F) (B : Matrix (Fin b) (Fin c) F) :Matrix (Fin a) (Fin c) F :=fun i k => P.program.eval (matrixInputs A B) (P.output i k)defCorrect (P : MatrixAlgorithm F a b c) : Prop := ∀ (A : Matrix (Fin a) (Fin b) F) (B : Matrix (Fin b) (Fin c) F), P.eval A B = A * Bdefcost (P : MatrixAlgorithm F a b c) : ℕ := P.program.costend MatrixAlgorithm/-- Positive slack, one uniform constant, and a correct program at every size. -/defAdmissibleExponent (F : Type*) [Field F] (τ : ℝ) : Prop := ∀ ε : ℝ, 0 < ε → ∃ C : ℝ, 0 < C ∧ ∀ n : ℕ, 1 ≤ n → ∃ P : MatrixAlgorithm F n n n, P.Correct ∧ (P.cost : ℝ) ≤ C * (n : ℝ) ^ (τ + ε)defomega (F : Type*) [Field F] : ℝ := sInf {τ : ℝ | AdmissibleExponent F τ}/-- The inner dimension of an `n × n^k` by `n^k × n` multiplication. -/definnerSize (n : ℕ) (k : ℝ) : ℕ := ⌈(n : ℝ) ^ k⌉₊defRectangularAdmissibleExponent (F : Type*) [Field F] (k τ : ℝ) : Prop := ∀ ε : ℝ, 0 < ε → ∃ C : ℝ, 0 < C ∧ ∀ n : ℕ, 1 ≤ n → ∃ P : MatrixAlgorithm F n (innerSize n k) n, P.Correct ∧ (P.cost : ℝ) ≤ C * (n : ℝ) ^ (τ + ε)defrectangularOmega (F : Type*) [Field F] (k : ℝ) : ℝ :=sInf {τ : ℝ | RectangularAdmissibleExponent F k τ}/-- The dual exponent is a supremum of exact exponent-two rectangular shapes. -/defcomplexAlpha : ℝ :=sSup {k : ℝ | k ∈ Set.Icc01 ∧ rectangularOmegaℂ k = 2}end MatrixMultiplication.Arithmeticendnamespace MatrixMultiplicationtheoremcomplex_omega_le_nine_quarters :Arithmetic.omegaℂ ≤ (9 : ℝ) / 4 := bysorrytheoremcomplex_alpha_gt_93_div_200 : (93 : ℝ) / 200 < Arithmetic.complexAlpha := bysorrytheoremcomplex_rectangular_omega_lt_523_div_250 :Arithmetic.rectangularOmegaℂ ((709 : ℝ) / 1000) < (523 : ℝ) / 250 := bysorryend MatrixMultiplicationend OAI
Every extracted statement of the accompanying papers
The statements the atlas extracted automatically from each accompanying paper’s TeX source, with links to the full sources.
A Lean statement states the theorem and leaves its proof as sorry on purpose. OpenAI’s proof is in a separate solution module, and a program called Comparator checks that proof against this statement.
Recorded comparisons with the paper
Atlas records no contributed comparison of this statement with the paper.
Contributed Comparator run reports
Atlas records no contributed report of running Comparator for this statement file.
More about this statement
Commentary The Lean statement gives the exponent bound 9/4 over the complex numbers, which is stronger than the 2.258 bound in the paper the documentation links; the nine-fourths manuscript it actually follows is not linked. Robert Joseph George, Do the Lean statements in openai/math match their papers?, 2026-10-07Source
Follow-up result Using an AI coding agent, the author extended the 9/4 exponent bound from the complex numbers to every field in Lean, and reports that Lean and Comparator checks pass. selanavot, matrix-multiplication-all-fields, 2026-10-07Source
Follow-up result Uznanski extends OpenAI's square matrix-multiplication analysis to rectangular products, giving omega(1,k,1) <= 2 for k up to 1/2 and an n^2.5 bound for Zwick's directed APSP algorithm. Przemyslaw Uznanski, Rectangular matrix multiplication from shared-leg entropy, 2026-10-07Source
Explanation Only one step of the complex 9/4 proof uses more than algebraic closure: Proposition 3.1 (Fourier separation) needs a primitive 5M-th root of unity, which fails when the characteristic divides 5M; a separation period of 3M-2 or 3M-1 keeps the downstream bound unchanged. Jeroen Zuiddam, Lean proof that the matrix multiplication exponent is at most 9/4 over every field, 2026-10-07Source
Follow-up result The symmetric, separately concave profiles satisfying the tripling inequality used in the 9/4 proof have an explicit least element, built from Gamma(m+1/3)/(Gamma(4/3)Gamma(m)), that meets the rank bound exactly at t = 3/4: 9/4 is the ceiling of this argument, and the paper's shift a - 1 is the smallest valid one. Checked in exact rationals for small cases. Eliott Cassidy, eliottcassidy2000/math: THM-4568, the 9/4 growth lemma is exactly sharp, 2026-10-07Source
Commentary Virginia Vassilevska Williams (MIT) notes the 9/4 exponent is far below the 2.37 reached by Vassilevska Williams and colleagues and describes it, with some irony, as language models speeding themselves up. Scientific American (byline not recorded), The most exciting claims from OpenAI's heap of new proofs, 2026-10-08Source
Follow-up result Independently of THM-4568 (credited as first), an explicit extremal profile satisfies all five properties the 9/4 proof uses with 1/t = 4/3, so they cannot yield an exponent below 9/4, and the diagonal-growth lemma is exactly optimal; the note extends the barrier to further valid inequalities and extractions. acprk, acprk/openai-math-followups: follow-up results on three OpenAI families, 2026-10-09Source
Questions to resolve when comparing this statement with the paper
Two independent readers, MathVet and cert-machine, disagree on whether this family's challenges state its headline; a specialist reading would settle it.