FormalConjectures/ErdosProblems/806.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: The upstream authors and contributors retain credit for the project and mathematics. lean4-explainer only renders their pinned source and adds the separately disclosed explanation layer.

Project sources: Pinned project documentation, Formal Conjectures paper, arXiv v1

3 declarations, 3 contain sorry, 0 declared as axioms

Erdős Problem 806

References:

Imports (1)
  1. theorem Erdos806.erdos_806 sorry line 54 source

    depends on sorry what this means

    Statement uses: Iff, True, Real, LT.lt, OfNat.ofNat, Filter.Eventually, Nat, Finset, LE.le, Finset.Icc, Finset.card, Real.sqrt, Exists, Int, And, Finset.map, Nat.castEmbedding, HAdd.hAdd, HMul.hMul, Filter.atTop

    Proof uses: sorryAx, Lean.Name, Bool.false, Lean.Name.num, Lean.Name.str, Lean.Name.anonymous

    44 instances, coercions and auxiliary constants left out.

    Tactic trace: 1 steps

    Open to load the checked before-and-after goal states.

  2. theorem Erdos806.erdos_806.variants.alon_bukh_sudakov Documented declaration: alon_bukh_sudakov sorry line 65 source

    Source documentation

    Alon, Bukh, and Sudakov [ABS09] proved that for any $A\subseteq \{1,\ldots,n\}$ with $\lvert A\rvert \leq n^{1/2}$ there exists some $B$ such that $A\subseteq B+B$ and $\lvert B\rvert \ll \frac{\log\log n}{\log n}n^{1/2}$.

    depends on sorry what this means

    Statement uses: Exists, Real, Filter.Eventually, Nat, Finset, LE.le, Finset.Icc, OfNat.ofNat, Finset.card, Real.sqrt, Int, And, Finset.map, Nat.castEmbedding, HAdd.hAdd, HMul.hMul, HDiv.hDiv, Real.log, Filter.atTop

    Proof uses: sorryAx, Lean.Name, Bool.false, Lean.Name.num, Lean.Name.str, Lean.Name.anonymous

    44 instances, coercions and auxiliary constants left out.

    Tactic trace: 1 steps

    Open to load the checked before-and-after goal states.

    theorem erdos_806.variants.alon_bukh_sudakov : ∃ C : ℝ, ∀ᶠ n : ℕ in atTop,
        ∀ A : Finset ℕ, A ⊆ Finset.Icc 1 n → (A.card : ℝ) ≤ √n →
          ∃ B : Finset ℤ, A.map Nat.castEmbedding ⊆ B + B ∧
            (B.card : ℝ) ≤ C * Real.log (Real.log n) / Real.log n * √n := by
    …
  3. theorem Erdos806.erdos_806.variants.erdos_newman Erdős and Newman [ErNe77] proved that there exist sorry line 77 source

    Source documentation

    Erdős and Newman [ErNe77] proved that there exist $A\subseteq\{1,\ldots,n\}$ with $\lvert A\rvert\asymp n^{1/2}$ such that if $A\subseteq B+B$ then $\lvert B\rvert \gg \frac{\log\log n}{\log n}n^{1/2}$.

    depends on sorry what this means

    Statement uses: Exists, Real, And, LT.lt, OfNat.ofNat, Filter.Eventually, Nat, Finset, LE.le, Finset.Icc, HMul.hMul, Real.sqrt, Finset.card, Int, Finset.map, Nat.castEmbedding, HAdd.hAdd, HDiv.hDiv, Real.log, Filter.atTop

    Proof uses: sorryAx, Lean.Name, Bool.false, Lean.Name.num, Lean.Name.str, Lean.Name.anonymous

    50 instances, coercions and auxiliary constants left out.

    Tactic trace: 1 steps

    Open to load the checked before-and-after goal states.

    theorem erdos_806.variants.erdos_newman : ∃ c : ℝ, 0 < c ∧ ∀ᶠ n : ℕ in atTop,
        ∃ A : Finset ℕ, A ⊆ Finset.Icc 1 n ∧ c * √n ≤ A.card ∧ (A.card : ℝ) ≤ √n ∧
          ∀ B : Finset ℤ, A.map Nat.castEmbedding ⊆ B + B →
            c * Real.log (Real.log n) / Real.log n * √n ≤ B.card := by
    …

    Mentions: c