OAI/Combinatorics/SharpThreshold/BlockLowDegree.lean

GitHub source file

6 declarations, 0 contain sorry, 0 declared as axioms

  1. theorem OAI.Problem313.average_conditional_low_degree_bound line 21

    Source documentation

    Averaging the low-degree estimate over exterior configurations preserves its linear influence bound. This is the fixed-block averaging step, before averaging in the choice of the vertex block.

    theorem average_conditional_low_degree_bound
        {ι : Type u} [Fintype ι] [DecidableEq ι]
        (P : ι → Prop) [DecidablePred P]
        (p k C : ℝ) (f : (ι → Bool) → Bool)
        (hp : 0 ≤ p) (hp1 : p ≤ 1)
        (hbound : ∀ y : {i // ¬ P i} → Bool,
          (∑ A : Finset {i // P i},
            if A.Nonempty ∧ (A.card : ℝ) ≤ k then
              BiasedFourier.coeff p
                (fun x => boolReal (f (RestrictionInfluence.join P x y))) A ^ 2
            else 0) ≤
          C * ∑ i : {i // P i}, RestrictionInfluence.influence p
    …

    Mentions: OAI.Problem313.BiasedFourier.coeff, OAI.Problem313.boolReal, OAI.Problem313.RestrictionInfluence.join, OAI.Problem313.RestrictionInfluence.influence

  2. theorem OAI.Problem313.original_mass_bound_of_conditional line 66

    Source documentation

    The same averaging step with the original Fourier mass supplied by the exact restriction identity. Both premises are equalities/inequalities about the actual canonical product cube, not an abstract replacement for graph probability.

    theorem original_mass_bound_of_conditional
        {ι : Type u} [Fintype ι] [DecidableEq ι]
        (P : ι → Prop) [DecidablePred P]
        (p k C M : ℝ) (f : (ι → Bool) → Bool)
        (hp : 0 ≤ p) (hp1 : p ≤ 1)
        (hmass : M =
          ∑ y : {i // ¬ P i} → Bool, BiasedFourier.weight p y *
            ∑ A : Finset {i // P i},
              if A.Nonempty ∧ (A.card : ℝ) ≤ k then
                BiasedFourier.coeff p
                  (fun x => boolReal (f (RestrictionInfluence.join P x y))) A ^ 2
              else 0)
    …

    Mentions: OAI.Problem313.BiasedFourier.weight, OAI.Problem313.BiasedFourier.coeff, OAI.Problem313.boolReal, OAI.Problem313.RestrictionInfluence.join

  3. theorem OAI.Problem313.block_conditional_low_degree_bound_of_estimate line 92

    Source documentation

    The conditional influence premise for the low-degree theorem follows from vertex invariance and the low-degree estimate on the restricted cube.

    theorem block_conditional_low_degree_bound_of_estimate
        {n : ℕ} (B : Finset (Fin n)) [DecidablePred (EdgeTouches B)]
        (hB : 3 ≤ B.card) (f : GraphConfig n → Bool) (hf : VertexInvariant f)
        (p k C : ℝ) (hp : 0 ≤ p) (hp1 : p ≤ 1)
        (hestimate : ∀ g : ({e : GraphEdge n // EdgeTouches B e} → Bool) → Bool,
          (∀ e, Reindex.influence p g e ≤
            (∑ d, Reindex.influence p g d) / (B.card : ℝ)) →
          (∑ A : Finset {e : GraphEdge n // EdgeTouches B e},
            if A.Nonempty ∧ (A.card : ℝ) ≤ k then
              BiasedFourier.coeff p (fun x => boolReal (g x)) A ^ 2 else 0) ≤
          C * ∑ e, Reindex.influence p g e) :
        (∑ y : {e : GraphEdge n // ¬ EdgeTouches B e} → Bool,
    …

    Mentions: OAI.Problem313.EdgeTouches, OAI.Problem313.GraphConfig, OAI.Problem313.VertexInvariant, OAI.Problem313.GraphEdge, OAI.Problem313.Reindex.influence, OAI.Problem313.BiasedFourier.coeff, OAI.Problem313.boolReal

  4. theorem OAI.Problem313.block_low_degree_bound_of_estimate line 132

    Source documentation

    Fixed-block Fourier estimate: all exterior Fourier degrees are retained. The only analytic input is the ordinary low-degree estimate on the free cube.

    theorem block_low_degree_bound_of_estimate
        {n : ℕ} (B : Finset (Fin n)) [DecidablePred (EdgeTouches B)]
        (hB : 3 ≤ B.card) (f : GraphConfig n → Bool) (hf : VertexInvariant f)
        (p k C : ℝ) (hp : 0 < p) (hp1 : p < 1)
        (hestimate : ∀ g : ({e : GraphEdge n // EdgeTouches B e} → Bool) → Bool,
          (∀ e, Reindex.influence p g e ≤
            (∑ d, Reindex.influence p g d) / (B.card : ℝ)) →
          (∑ A : Finset {e : GraphEdge n // EdgeTouches B e},
            if A.Nonempty ∧ (A.card : ℝ) ≤ k then
              BiasedFourier.coeff p (fun x => boolReal (g x)) A ^ 2 else 0) ≤
          C * ∑ e, Reindex.influence p g e) :
        (∑ S : Finset (GraphEdge n),
    …

    Mentions: OAI.Problem313.EdgeTouches, OAI.Problem313.GraphConfig, OAI.Problem313.VertexInvariant, OAI.Problem313.GraphEdge, OAI.Problem313.Reindex.influence, OAI.Problem313.BiasedFourier.coeff, OAI.Problem313.boolReal

  5. theorem OAI.Problem313.block_low_degree_bound line 154

    Source documentation

    The fixed-block low-degree Fourier bound for invariant graph properties. All symmetry, restriction and analytic premises are discharged.

    theorem block_low_degree_bound
        {n : ℕ} (B : Finset (Fin n)) [DecidablePred (EdgeTouches B)]
        (hB : 3 ≤ B.card) (f : GraphConfig n → Bool) (hf : VertexInvariant f)
        {p : ℝ} (hp : 0 < p) (hp1 : p < 1) :
        (∑ S : Finset (GraphEdge n),
          if (S.filter (EdgeTouches B)).Nonempty ∧
              ((S.filter (EdgeTouches B)).card : ℝ) ≤
                Real.sqrt (p * (1 - p)) * Real.log (B.card : ℝ) / 64 then
            BiasedFourier.coeff p (fun x => boolReal (f x)) S ^ 2 else 0) ≤
          (B.card : ℝ) ^ (-1 / 4 : ℝ) *
            ∑ e : {e : GraphEdge n // EdgeTouches B e}, edgeInfluence p f e.val := by
    …

    Mentions: OAI.Problem313.EdgeTouches, OAI.Problem313.GraphConfig, OAI.Problem313.VertexInvariant, OAI.Problem313.GraphEdge, OAI.Problem313.BiasedFourier.coeff, OAI.Problem313.boolReal, OAI.Problem313.edgeInfluence

  6. theorem OAI.Problem313.block_low_degree_bound_filter line 172

    Source documentation

    Filtered finite-sum version of the fixed-block low-degree bound.

    theorem block_low_degree_bound_filter
        {n : ℕ} (B : Finset (Fin n)) [DecidablePred (EdgeTouches B)]
        (hB : 3 ≤ B.card) (f : GraphConfig n → Bool) (hf : VertexInvariant f)
        {p : ℝ} (hp : 0 < p) (hp1 : p < 1) :
        (∑ S ∈ Finset.univ.filter (fun S : Finset (GraphEdge n) =>
          1 ≤ (S.filter (EdgeTouches B)).card ∧
            ((S.filter (EdgeTouches B)).card : ℝ) ≤
              Real.sqrt (p * (1 - p)) * Real.log (B.card : ℝ) / 64),
          BiasedFourier.coeff p (fun x => boolReal (f x)) S ^ 2) ≤
          (B.card : ℝ) ^ (-1 / 4 : ℝ) *
            ∑ e ∈ Finset.univ.filter (EdgeTouches B), edgeInfluence p f e := by
    …

    Mentions: OAI.Problem313.EdgeTouches, OAI.Problem313.GraphConfig, OAI.Problem313.VertexInvariant, OAI.Problem313.GraphEdge, OAI.Problem313.BiasedFourier.coeff, OAI.Problem313.boolReal, OAI.Problem313.edgeInfluence