ComparatorChallenges/SubpolynomialLp.lean

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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

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

5 declarations, 1 contain sorry, 0 declared as axioms

  1. def OAI.SubpolynomialLp.coordinateDistance line 12

    Also declared: OAI/Analysis/LpDimension/Model.lean:12 (same declaration text).

  2. def OAI.SubpolynomialLp.GoodDimension The universal property used in the definition of d_p(n,D) line 16

    Source documentation

    The universal property used in the definition of d_p(n,D).

    L4DEL explanation

    The universal property used in the definition of d_p(n,D).

    1. This explanation is a condensed rendering of the declaration's own doc comment at the pinned source commit; consult the exact Lean statement below for authority.

    Sources and attribution: Pinned Lean source (fd4aeeb2ee4f)

    Also declared: OAI/Analysis/LpDimension/Model.lean:16 (same declaration text).

    def GoodDimension (p : ℝ) (n : ℕ) (D : ℝ) (d : ℕ) : Prop :=
    …
  3. def OAI.SubpolynomialLp.dimension The least universal coordinate dimension line 26

    Source documentation

    The least universal coordinate dimension. The theorem also asserts that this least dimension has the defining property, ruling out an empty infimum.

    L4DEL explanation

    The least universal coordinate dimension. The theorem also asserts that this least dimension has the defining property, ruling out an empty infimum.

    1. This explanation is a condensed rendering of the declaration's own doc comment at the pinned source commit; consult the exact Lean statement below for authority.

    Sources and attribution: Pinned Lean source (fd4aeeb2ee4f)

    Also declared: OAI/Analysis/LpDimension/Model.lean:26 (same declaration text).

    def dimension (p : ℝ) (n : ℕ) (D : ℝ) : ℕ :=
    …
  4. def OAI.SubpolynomialLp.gamma line 29

    Also declared: OAI/Analysis/LpDimension/Model.lean:29 (same declaration text).

  5. theorem OAI.SubpolynomialLp.source_main Challenge statement: Subpolynomial dimension reduction in Lp sorry line 32

    Source documentation

    The universal coordinate dimension bounds and their logarithmic limits.

    L4DEL explanation

    For $p>1$, $p\ne2$, the formalization bounds the least dimension needed to embed every $n$-point subset of real $L_p$ with distortion $D$. For each fixed $D>1$, there is a constant $C=C(p,D)$ such that this dimension lies between $\log n/\log(1+2D)$ and $\exp(C(\log n)^{\gamma(p)})$ for every $n\ge2$, where $\gamma(p)=2-p$ for $p<2$ and $1-2/p$ for $p>2$. At distortion $1$ and $n\ge9$, it lies between $\lfloor(n-1)/4\rfloor^2$ and $\binom n2$. The least dimension is attained, and its logarithm divided by $\log n$ tends to $0$ for $D>1$ and to $2$ for $D=1$.

    1. This is an exact comparator target linked by the pinned repository's formalization note for this result.
    2. The repository's comparator configuration selects OAI.Analysis.LpDimension.Main as the released solution module checked against this declaration.

    Sources and attribution: Pinned Lean source (fd4aeeb2ee4f)

    Distinct definitions of this name: OAI/Analysis/LpDimension/Main.lean:13 (same statement text; different proof or body). Qualify references as OAI.SubpolynomialLp.source_main@path.

    theorem source_main (p : ℝ) (hp : 1 < p) (hp2 : p ≠ 2) :
        (∀ D : ℝ, 1 < D → ∃ C : ℝ, ∀ n : ℕ, 2 ≤ n →
          GoodDimension.{u} p n D (dimension.{u} p n D) ∧
          Real.log (n : ℝ) / Real.log (1 + 2 * D) ≤ (dimension.{u} p n D : ℝ) ∧
          (dimension.{u} p n D : ℝ) ≤ Real.exp (C * Real.log (n : ℝ) ^ gamma p)) ∧
        (∀ n : ℕ, 9 ≤ n →
          GoodDimension.{u} p n 1 (dimension.{u} p n 1) ∧
          ((n - 1) / 4) ^ 2 ≤ dimension.{u} p n 1 ∧
          dimension.{u} p n 1 ≤ n.choose 2) ∧
        (∀ D : ℝ, 1 ≤ D →
          Tendsto (fun n : ℕ => Real.log (dimension.{u} p n D : ℝ) / Real.log (n : ℝ))
            atTop (𝓝 (if 1 < D then 0 else 2))) := by
    …

    Mentions: OAI.SubpolynomialLp.gamma