`ComparatorChallenges/ProductBrown.lean`

Explanation legend Lean4 Domain Explanation Language (L4DEL)

L4DEL explanations are a separate layer. They do not change the Lean source. Intuition is explanatory prose; numbered items are a reading path; sources link the wording back to evidence.

L4DEL: Lean4 Domain Explanation Language

Annotation provenance. This overlay contains 120 curated AI-written annotations and 1273 mechanical source-derived annotations. They have not been human-reviewed as explanations; treat them as unverified and not mathematical authority. Retained generation history: The 9 original curated annotations were produced in a Claude Sonnet 5.5 session at medium effort; Claude Opus 5.5 is recorded in that session as the advisor model, not the direct author. Those 9 annotations were revised on 2026-10-14 to bind all of them to exact page-one quotations from 6 pinned OpenAI manuscripts, the matching pinned formalization notes, and named historical primary sources; no human review is claimed, and the exact runtime model identifier was not exposed to the artifact generator. The 3 manuscript-grounded matrix-multiplication annotations were composed from pinned OpenAI manuscripts and named historical sources in a Codex session on 2026-10-14; no human review is claimed, and the exact runtime model identifier was not exposed to the artifact generator. Six additional target-specific annotations for Catalan's constant, the irrationality exponent of pi, dyadic Erdos similarity, Unique Games, quintic Lienard systems, and Yau nodal growth were composed from pinned OpenAI manuscripts, exact page-one quotations, exact Lean statements, and named historical sources in a Codex session on 2026-10-14; no human review is claimed, and the exact runtime model identifier was not exposed to the artifact generator. Four additional target-specific annotations for Seymour's second-neighborhood conjecture, Cannon's conjecture, Koebe circle-domain uniformization, and circle-domain rigidity were composed from 4 pinned OpenAI manuscripts, exact page-one quotations, exact Lean statements, and named historical primary sources in a Codex session on 2026-10-14; no human review is claimed, and the exact runtime model identifier was not exposed to the artifact generator. Four additional target-specific annotations for simple Lebesgue spectrum on the three-torus, Rokhlin multiple mixing, the nine-dimensional Borsuk counterexample, and Tingley's sphere-isometry problem were composed from 4 pinned OpenAI manuscripts, exact page-one quotations, exact Lean statements, and named historical primary sources in a Codex session on 2026-10-14; no human review is claimed, and the exact runtime model identifier was not exposed to the artifact generator. Four additional target-specific annotations for the Abhyankar-Sathaye counterexample, the circulant Hadamard conjecture, the Eilenberg-Ganea counterexample, and short Egyptian fractions were composed from 4 pinned OpenAI manuscripts, exact page-one quotations, exact Lean statements, and quotations from Sathaye, Turyn with Storer, Eilenberg with Ganea, and Erdos in a Codex session on 2026-10-14; no human review is claimed, and the exact runtime model identifier was not exposed to the artifact generator. Four additional target-specific annotations for the complete Crouzeix inequality, unrestricted Euclidean five-coloring, the general Mahler conjecture, and Thompson F nonamenability were composed on 2026-10-14 from exact Lean statements, 4 pinned OpenAI manuscripts, the matching formalization notes, and linked historical sources by Crouzeix, de Grey, Mahler, Cannon, Floyd, and Parry; no human review is claimed. Four additional target-specific annotations for algorithmic strong thin trees, Barnette's Hamiltonian-cycle conjecture, the explicit Artin CAT(0) counterexample, and generalized amplitude-damping capacity were composed on 2026-10-14 from exact Lean statements, 4 pinned OpenAI manuscripts, matching formalization notes, and linked historical sources by Anari with Goddyn, Arts with Hopman and Timmermans, Charney, and Khatri with Sharma and Wilde; no human review is claimed. Fourteen solution-level annotations for Seymour's second-neighborhood theorem were added on 2026-10-14 from the pinned 15-page manuscript, covering the exact-neighborhood model, minimal-counterexample reduction, subset deficit, transitive blowup, pruning, extremal contradiction, and proof-bearing final theorem. The subset and blowup annotations also bind exact quotations from Tyler Seacrest (2019) and Brantner, Brockman, Kay, and Snively (2009); no human review is claimed. Thirty-seven declaration-level annotations were added on 2026-10-14 for the rest of ComparatorChallenges/AlgorithmicThinTrees.lean, covering its multigraph semantics, stack-machine cost model, explicit and binary-multiplicity encodings, output certificate, and complete algorithmic proposition. They are bound to the pinned OpenAI manuscript and linked earlier thin-tree sources by Luis Goddyn, Nima Anari, and Shayan Oveis Gharan; the annotation explicitly preserves that the concluding comparator theorem still has body by sorry, and no human review is claimed. Thirty-one supporting declarations in ComparatorChallenges/UniqueGamesTheorem.lean were upgraded or added on 2026-10-14, completing curated coverage of all thirty-two declarations in that file. The annotations cover the finite game model, Boolean formula and parser, binary-vector translations, explicit output serialization, finite-alphabet machine contract, and gap theorem; they distinguish manuscript-backed mathematics from Lean-specific canonical parsing and unary game output encoding, bind exact OpenAI manuscript quotations, and credit Subhash Khot through his 2010 survey. The comparator theorem remains explicitly labeled as having body by sorry; no human review is claimed. The source-derived generator was hardened on 2026-10-14 so a formalization note covering multiple comparator results no longer copies its combined Scope prose onto each declaration; those targets now use declaration-specific source comments when available and otherwise remain explicitly bounded to the exact Lean statement. The remaining source-derived annotations were generated mechanically from pinned formalization notes and source comments by tooling developed in a GPT-5.6 Sol session at ultra reasoning; GPT-5.6 Sol did not originate the source prose.

Credit: OpenAI's pinned repository says an unreleased internal model produced the manuscripts and supporting proof artifacts. The collection builds on the mathematics community's accumulated problems, results, language, and formal libraries; each manuscript's BibTeX and bibliography are the authority for individual scholarly credit.

Project sources: Pinned openai/math documentation, Pinned formalization catalogue

66 declarations, 1 contain sorry, 0 declared as axioms

theorem OAI.FiniteFactor.product_has_low_nonzero_coeff line 10
Also declared: OAI/Analysis/FiniteFactor/Polynomial.lean:8 (same declaration text).
abbrev OAI.FiniteFactor.Coefficients line 22
Also declared: OAI/Analysis/FiniteFactor/Polynomial.lean:20 (same declaration text).
def OAI.FiniteFactor.coefficientPolynomial line 24
Also declared: OAI/Analysis/FiniteFactor/Polynomial.lean:22 (same declaration text).
theorem OAI.FiniteFactor.coefficientPolynomial_coeff line 27
Also declared: OAI/Analysis/FiniteFactor/Polynomial.lean:25 (same declaration text).
def OAI.FiniteFactor.productCoefficient line 33
Also declared: OAI/Analysis/FiniteFactor/Polynomial.lean:31 (same declaration text).
theorem OAI.FiniteFactor.productCoefficient_eq line 37
Also declared: OAI/Analysis/FiniteFactor/Polynomial.lean:35 (same declaration text).
theorem OAI.FiniteFactor.continuous_productCoefficient line 45
Also declared: OAI/Analysis/FiniteFactor/Polynomial.lean:43 (same declaration text).
def OAI.FiniteFactor.lowCoefficients line 56
Also declared: OAI/Analysis/FiniteFactor/Polynomial.lean:54 (same declaration text).
theorem OAI.FiniteFactor.continuous_lowCoefficients line 59
Also declared: OAI/Analysis/FiniteFactor/Polynomial.lean:57 (same declaration text).
theorem OAI.FiniteFactor.lowCoefficients_ne_zero line 62
Also declared: OAI/Analysis/FiniteFactor/Polynomial.lean:60 (same declaration text).
def OAI.FiniteFactor.admissibleCoefficients line 74
Also declared: OAI/Analysis/FiniteFactor/Polynomial.lean:72 (same declaration text).
theorem OAI.FiniteFactor.isCompact_admissibleCoefficients line 77
Also declared: OAI/Analysis/FiniteFactor/Polynomial.lean:75 (same declaration text).
theorem OAI.FiniteFactor.uniform_product_coefficient_bound line 85
Also declared: OAI/Analysis/FiniteFactor/Polynomial.lean:83 (same declaration text).
def OAI.FiniteFactor.unitIntervalMeasure line 125
Also declared: OAI/Analysis/FiniteFactor/Coupling/Mixture.lean:63 (same declaration text).
instance OAI.FiniteFactor.(instance at line 127) line 127
def OAI.FiniteFactor.sourceKappa line 141
Also declared: OAI/Analysis/FiniteFactor/Coupling/Products.lean:12 (same declaration text).
def OAI.FiniteFactor.sourceNextCutoff line 153
Also declared: OAI/Analysis/FiniteFactor/CrossedProduct/Stages.lean:12 (same declaration text).
theorem OAI.FiniteFactor.sourceNextCutoff_large line 155
Also declared: OAI/Analysis/FiniteFactor/CrossedProduct/Stages.lean:14 (same declaration text).
theorem OAI.FiniteFactor.exists_source_block_length line 166
Also declared: OAI/Analysis/FiniteFactor/CrossedProduct/Stages.lean:25 (same declaration text).
structure OAI.FiniteFactor.SourceStageState line 195
Also declared: OAI/Analysis/FiniteFactor/CrossedProduct/Stages.lean:56 (same declaration text).
def OAI.FiniteFactor.SourceStageState.D line 206
Also declared: OAI/Analysis/FiniteFactor/CrossedProduct/Stages.lean:67 (same declaration text).
structure OAI.FiniteFactor.SourceStageChoice line 208
Also declared: OAI/Analysis/FiniteFactor/CrossedProduct/Stages.lean:71 (same declaration text).
theorem OAI.FiniteFactor.exists_sourceStageChoice line 230
Also declared: OAI/Analysis/FiniteFactor/CrossedProduct/Stages.lean:93 (same declaration text).
def OAI.FiniteFactor.selectedSourceStage line 265
Also declared: OAI/Analysis/FiniteFactor/CrossedProduct/Stages.lean:128 (same declaration text).
def OAI.FiniteFactor.SourceStageChoice.C line 268
Also declared: OAI/Analysis/FiniteFactor/CrossedProduct/Stages.lean:131 (same declaration text).
def OAI.FiniteFactor.SourceStageChoice.next line 271
Also declared: OAI/Analysis/FiniteFactor/CrossedProduct/Stages.lean:134 (same declaration text).
def OAI.FiniteFactor.sourceStageState line 282
Also declared: OAI/Analysis/FiniteFactor/CrossedProduct/Stages.lean:147 (same declaration text).
def OAI.FiniteFactor.sourceStage line 286
Also declared: OAI/Analysis/FiniteFactor/CrossedProduct/Stages.lean:151 (same declaration text).
def OAI.FiniteFactor.coordinateFloor line 299
Also declared: OAI/Analysis/FiniteFactor/CrossedProduct/FloorSupport.lean:41 (same declaration text).
def OAI.FiniteFactor.coordinateRotate line 312
Also declared: OAI/Analysis/FiniteFactor/CrossedProduct/Cocycle.lean:12 (same declaration text).
def OAI.FiniteFactor.sourceLog line 315
Also declared: OAI/Analysis/FiniteFactor/CrossedProduct/Cocycle.lean:39 (same declaration text).
def OAI.FiniteFactor.sourceCocycle line 318
Also declared: OAI/Analysis/FiniteFactor/CrossedProduct/Cocycle.lean:42 (same declaration text).
theorem OAI.FiniteFactor.sourceCocycle_pos line 321
Also declared: OAI/Analysis/FiniteFactor/CrossedProduct/Cocycle.lean:72 (same declaration text).
theorem OAI.FiniteFactor.sourceCocycle_measurable line 324
Also declared: OAI/Analysis/FiniteFactor/CrossedProduct/Cocycle.lean:81 (same declaration text).
theorem OAI.FiniteFactor.sourceWeight_le_one line 338
Also declared: OAI/Analysis/FiniteFactor/CrossedProduct/Cocycle.lean:96 (same declaration text).
abbrev OAI.FiniteFactor.sourceMeasure line 359
Also declared: OAI/Analysis/FiniteFactor/CrossedProduct/Operator.lean:14 (same declaration text).
abbrev OAI.FiniteFactor.SourceHilbert line 362
Also declared: OAI/Analysis/FiniteFactor/CrossedProduct/Operator.lean:17 (same declaration text).
def OAI.FiniteFactor.sourceDiagonal line 364
Also declared: OAI/Analysis/FiniteFactor/CrossedProduct/Operator.lean:20 (same declaration text).
theorem OAI.FiniteFactor.sourceDiagonal_measurable line 367
Also declared: OAI/Analysis/FiniteFactor/CrossedProduct/Operator.lean:23 (same declaration text).
theorem OAI.FiniteFactor.sourceDiagonal_norm_le line 376
Also declared: OAI/Analysis/FiniteFactor/CrossedProduct/Operator.lean:32 (same declaration text).
theorem OAI.FiniteFactor.sourceDiagonal_memLp line 384
Also declared: OAI/Analysis/FiniteFactor/CrossedProduct/Operator.lean:45 (same declaration text).
def OAI.FiniteFactor.sourceMultiplication line 390
Also declared: OAI/Analysis/FiniteFactor/CrossedProduct/Operator.lean:52 (same declaration text).
def OAI.FiniteFactor.sourceShiftIndex line 395
Also declared: OAI/Analysis/FiniteFactor/CrossedProduct/Operator.lean:76 (same declaration text).
theorem OAI.FiniteFactor.sourceShiftIndex_preserving line 397
Also declared: OAI/Analysis/FiniteFactor/CrossedProduct/Operator.lean:78 (same declaration text).
def OAI.FiniteFactor.sourceShift line 409
Also declared: OAI/Analysis/FiniteFactor/CrossedProduct/Operator.lean:90 (same declaration text).
def OAI.FiniteFactor.sourceOperator line 412
Also declared: OAI/Analysis/FiniteFactor/CrossedProduct/Operator.lean:95 (same declaration text).
abbrev OAI.FiniteFactor.CouplingParameters.BlockCoordinate line 427
Also declared: OAI/Analysis/FiniteFactor/Coupling/BlockLimit.lean:13 (same declaration text).
def OAI.FiniteFactor.sourceBlockSize line 440
Also declared: OAI/Analysis/FiniteFactor/CrossedProduct/StageOperator.lean:12 (same declaration text).
abbrev OAI.FiniteFactor.SourceCoordinate line 441
Also declared: OAI/Analysis/FiniteFactor/CrossedProduct/StageOperator.lean:13 (same declaration text).
def OAI.FiniteFactor.sourceLogWeight line 443
Also declared: OAI/Analysis/FiniteFactor/CrossedProduct/StageOperator.lean:15 (same declaration text).
def OAI.FiniteFactor.SourceAngles line 445
Also declared: OAI/Analysis/FiniteFactor/CrossedProduct/StageOperator.lean:17 (same declaration text).
theorem OAI.FiniteFactor.sourceBlockSize_pos line 459
Also declared: OAI/Analysis/FiniteFactor/CrossedProduct/StageOperator.lean:31 (same declaration text).
theorem OAI.FiniteFactor.sourceCutoff_pos line 462
Also declared: OAI/Analysis/FiniteFactor/CrossedProduct/StageOperator.lean:34 (same declaration text).
theorem OAI.FiniteFactor.SourceAngles.nonneg line 465
Also declared: OAI/Analysis/FiniteFactor/CrossedProduct/StageOperator.lean:53 (same declaration text).
theorem OAI.FiniteFactor.sourceLogWeight_nonneg line 497
Also declared: OAI/Analysis/FiniteFactor/CrossedProduct/StageOperator.lean:85 (same declaration text).
def OAI.FiniteFactor.sourceVacuum line 510
Also declared: OAI/Analysis/FiniteFactor/CrossedProduct/VacuumFunctional.lean:13 (same declaration text).
theorem OAI.FiniteFactor.sourceVacuum_norm line 537
Also declared: OAI/Analysis/FiniteFactor/CrossedProduct/VacuumFunctional.lean:40 (same declaration text).
abbrev OAI.FiniteFactor.sourceVacuumFunctional line 583
Also declared: OAI/Analysis/FiniteFactor/CrossedProduct/VacuumFunctional.lean:86 (same declaration text).
instance OAI.FiniteFactor.productHilbertNontrivial line 618
Also declared: OAI/Analysis/BrownMeasure/Model.lean:14 (same declaration text).
abbrev OAI.FiniteFactor.ProductOp line 678
Also declared: OAI/Analysis/BrownMeasure/Model.lean:73 (same declaration text).
def OAI.FiniteFactor.logarithmCutoff line 692
Also declared: OAI/Analysis/BrownMeasure/Model.lean:86 (same declaration text).
def OAI.FiniteFactor.FugledeKadisonDeterminant line 699
Also declared: OAI/Analysis/BrownMeasure/Model.lean:93 (same declaration text).
def OAI.FiniteFactor.expLogPotential line 723
Also declared: OAI/Analysis/BrownMeasure/Model.lean:117 (same declaration text).
def OAI.FiniteFactor.IsBrownMeasure line 726
Also declared: OAI/Analysis/BrownMeasure/Model.lean:120 (same declaration text).
def OAI.FiniteFactor.ProductBrownClaim line 738
Also declared: OAI/Analysis/BrownMeasure/Model.lean:132 (same declaration text).
theorem OAI.FiniteFactor.productBrown Challenge statement: Brown measure of the selected product weighted shift sorry line 752
Source documentation
The Brown measure of the product weighted shift is the point mass at zero.
L4DEL explanation
The Brown measure of the product weighted shift is the point mass at zero.
1. This explanation is a condensed rendering of this declaration's own doc comment at the pinned source commit.
2. The linked formalization note covers 6 distinct comparator results, so its combined Scope prose is not copied onto this declaration.
3. The repository's comparator configuration selects OAI.Analysis.BrownMeasure.Main as the released solution module checked against this declaration.
Sources and attribution: Pinned Lean source (fd4aeeb2ee4f)
Distinct definitions of this name: OAI/Analysis/BrownMeasure/Main.lean:14 (same statement text; different proof or body). Qualify references as OAI.FiniteFactor.productBrown@path.
```
theorem productBrown : ProductBrownClaim := by
…
```
Mentions: OAI.FiniteFactor.ProductBrownClaim