State of Proof

Mathematics · Theoretical result · Source record; see version · examination not started

The Exponential Time Hypothesis is False

OpenAI.

Source date: 2026-10-25 · Added: 2026-10-26 · Record updated:

Inclusion is not validation. This is an intake record and proposed check plan, not a completed examination or a peer-review decision. Any separate docket states its own exact source and scope.

Mathematics · Theoretical result · Source record; see version

Candidate · added · paper-2026-10-26-the-exponential-time-hypothesis-is-false

A tree of blue glass tiles branches into the distance while teal ribbons gather several paths.
Conceptual illustration · not experimental data, a reproduction, or a proof certificate

A central assumption about computing time faces a claimed refutation

What it is
A manuscript claims an algorithm that counts solutions to fixed-width Boolean formulas in subexponential time and polynomial space.
Who did it
OpenAI; an external group led by Russell Impagliazzo, Ramamohan Paturi and Ryan Williams will examine and explain the work.
What it could mean
If correct, it would overturn a widely used assumption about worst-case computing time. It does not resolve P versus NP or demonstrate a practical solver improvement.

Examination not started

See the check plan

Evidence & validation

From announcement to evidence

Discovery recorded. State of Proof has not yet examined this claim.

  1. Read the original work

    The Exponential Time Hypothesis is False ↗

    OpenAI.

  2. See the proposed checks

    Inspect the fixed-k quantifiers, canonical encoding and concrete machine endpoint, then compare its time and all-prefix space bounds with the manuscript. Keep the manuscript's single-log-log factor and sparse-clause refinement separate from Lean's squared-log-log factor. Select one bounded correspondence check before any isolated replay; no P=NP or practical speedup follows.

  3. No proof docket yet

    A docket is the public record of checks and open questions. This paper does not have one yet; the check plan above describes work still to do.

    Explore existing proof dockets →
How validation works →

Structure inside a vast search

The branching tiles introduce the combinations in a Boolean search. The gathered ribbons are a conceptual metaphor, not the submitted algorithm or a measured speedup.

Read the source · Introduction · fixed-width exact counting; lean/docs/378.md · weaker formal runtime ↗
Source kind
Mathematical research record
Evidence reported
Manuscript; independent examination not started
Source date
; added 2026-10-26
What it claims
For fixed k≥2, the manuscript claims exact counting on n-variable, m-clause k-CNF formulas in (n+m)^Ok(1) times 2^Ok(n log log n / sqrt(log n)), using polynomial space; for m≤Dn with fixed D, the exponent improves to O(k,D)(n / sqrt(log n)). The public Lean scope instead gives the weaker exponent Ok(n (log log n)² / sqrt(log n)) with a polynomial canonical-input-length factor, still subexponential.
Why this could matter
A central assumption about computing time faces a claimed refutation Many conditional speed limits assume that solving three-variable Boolean clauses needs exponentially growing time. The claimed algorithm grows more slowly asymptotically and also counts solutions. The public formalization advertises a weaker time bound than the manuscript.
If it holds up
Researchers would revisit hardness claims that depend on ETH and investigate which algorithmic ideas yield useful improvements on actual workloads.
If it does not
A failed reduction, time bound or formal correspondence would identify the gap; it would not prove ETH true.
Impact horizon
Foundational · Computational complexity · Exact counting · Algorithms
Version
2026-10-25; October 17 manuscript, revised October 25, 2026; public release at Git commit 7ef5c0cc5ca4b0e072b7a050fca09ab24bc6fa3a.
Why we tracked it
source-reviewed intake only; independent examination has not started.
Highest-risk dependency
Analyst judgment: the precise fixed-width encoding, machine-cost model, reduction overhead and manuscript-to-Lean correspondence are load-bearing. Lean's advertised exponent has (log log n)²; the sharper prose bound has log log n, with an additional sparse-case improvement. A replay of the weaker endpoint would not by itself certify those sharper bounds. This is source intake only, not proof validation, polynomial-time SAT or demonstrated commercial acceleration.
Available artifacts
Pinned openai/math 7ef5c0cc5ca4b0e072b7a050fca09ab24bc6fa3a; paper.pdf (Git blob 0503566e95bc587a4076573a45132d97531b8ba6), lean/docs/378.md, lean/OAI/Algorithms/SubexponentialSAT/SqrtLogSpace/Final.lean and lean/ComparatorChallenges/SubexponentialSAT.json. Lean v4.34.1; Mathlib d13f23b723b8a846827a245b89c10fc7d3f11612. The comparator permits the three listed standard axioms and disables nanoda. No State of Proof build or checker run occurred.
Current boundary
Intake record only; examination not started. State of Proof has only recorded this intake. The paper's full argument remains unexamined; the next bounded check is: Inspect the fixed-k quantifiers, canonical encoding and concrete machine endpoint, then compare its time and all-prefix space bounds with the manuscript. Keep the manuscript's single-log-log factor and sparse-clause refinement separate from Lean's squared-log-log factor. Select one bounded correspondence check before any isolated replay; no P=NP or practical speedup follows.

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