OAI/NumberTheory/JointDickman/Counting/SamplingConcentration.lean

GitHub source file

20 declarations, 0 contain sorry, 0 declared as axioms

Concentration after restriction to a common good event

The extension used in the manuscript's sampling argument is constructed explicitly from a finite good set. The only concentration hypothesis below is the uniform-constant finite-product specialization of McDiarmid's published bounded-differences inequality.

  1. def OAI.JointDickman.goodSetExtension line 25

    Source documentation

    The finite McShane extension, clamped at the chosen upper bound.

    noncomputable def goodSetExtension (G : Finset (ι → A)) (hG : G.Nonempty)
        (f : (ι → A) → ℝ) (c L : ℝ) (x : ι → A) : ℝ :=
    …
  2. theorem OAI.JointDickman.goodSetExtension_le line 29
  3. theorem OAI.JointDickman.goodSetExtension_nonneg line 33
  4. theorem OAI.JointDickman.goodSetExtension_eq line 42
  5. theorem OAI.JointDickman.min_upper_add line 60
  6. theorem OAI.JointDickman.goodSetExtension_lipschitz line 68
  7. def OAI.JointDickman.finiteExpectation line 98

    Source documentation

    Expectation with respect to an explicitly supplied finite mass function.

    noncomputable def finiteExpectation (w : Ω → ℝ) (f : Ω → ℝ) : ℝ :=
    …
  8. def OAI.JointDickman.finiteProbability line 102

    Source documentation

    Event mass for the same finite law.

    noncomputable def finiteProbability (w : Ω → ℝ) (E : Ω → Prop) : ℝ :=
    …
  9. theorem OAI.JointDickman.finiteProbability_mono line 105
  10. theorem OAI.JointDickman.finiteProbability_union_le line 115
  11. theorem OAI.JointDickman.finiteProbability_union_on_good line 134

    Source documentation

    A common exceptional event is paid once, before the union over tests.

    theorem finiteProbability_union_on_good {J : Type*} [Fintype J]
        (w : Ω → ℝ) (hw : ∀ x, 0 ≤ w x) (G : Ω → Prop) (E : J → Ω → Prop) :
        finiteProbability w (fun x => ∃ j, E j x) ≤
          finiteProbability w (fun x => ¬ G x) +
            ∑ j, finiteProbability w (fun x => G x ∧ E j x) := by
    …

    Mentions: OAI.JointDickman.finiteProbability

  12. theorem OAI.JointDickman.goodSetExtension_mean_le line 159
  13. def OAI.JointDickman.PublishedInputs.siteProductMass line 189

    Source documentation

    Independent site mass, retaining the actual coordinate laws.

    noncomputable def siteProductMass {ι A : Type*} [Fintype ι]
        (p : ι → A → ℝ) (x : ι → A) : ℝ := ∏ i, p i (x i)
  14. def OAI.JointDickman.PublishedInputs.FiniteMcDiarmidInput line 198

    Source documentation

    McDiarmid, On the method of bounded differences, Surveys in Combinatorics 1989, Theorem (6.7), pp. 166–167 (proof p. 168), DOI 10.1017/CBO9781107359949.008. The one-sided estimate follows by applying that martingale theorem to the coordinate Doob martingale. Only independent finite sites and one common coordinate bound are needed. The global Hamming bound is a stronger sufficient hypothesis on f.

    def FiniteMcDiarmidInput (ι A : Type*) [Fintype ι] [DecidableEq ι]
        [Fintype A] [DecidableEq A] : Prop :=
    …
  15. theorem OAI.JointDickman.abs_clamp_sub_clamp_le line 214
  16. theorem OAI.JointDickman.goodSet_concentration line 219

    Source documentation

    A concentration bound valid on one common good event. The cost of the bad event enters the mean only once, before any later union bound.

    theorem goodSet_concentration (hMC : PublishedInputs.FiniteMcDiarmidInput ι A)
        (p : ι → A → ℝ) (hp : ∀ i a, 0 ≤ p i a) (hpone : ∀ i, ∑ a, p i a = 1)
        (G : Finset (ι → A)) (hG : G.Nonempty) (Z : (ι → A) → ℝ)
        {c L u a : ℝ} (hc : 0 ≤ c) (hL : 0 ≤ L) (ha : 0 < a)
        (hZ : ∀ x, 0 ≤ Z x)
        (hlip : ∀ x ∈ G, ∀ y ∈ G, |Z x - Z y| ≤ c * hammingDist x y)
        (hmean : finiteExpectation (PublishedInputs.siteProductMass p) Z +
          L * finiteProbability (PublishedInputs.siteProductMass p) (fun x => x ∉ G) ≤ u)
        (hcut : u + a < L) :
        finiteProbability (PublishedInputs.siteProductMass p)
          (fun x => x ∈ G ∧ u + a < Z x) ≤
            Real.exp (-2 * a ^ 2 / ((Fintype.card ι : ℝ) * c ^ 2)) := by
    …

    Mentions: OAI.JointDickman.PublishedInputs.FiniteMcDiarmidInput, OAI.JointDickman.finiteExpectation, OAI.JointDickman.PublishedInputs.siteProductMass, OAI.JointDickman.finiteProbability

  17. theorem OAI.JointDickman.column_abs_sum_sub_le line 264
  18. theorem OAI.JointDickman.incident_change_mass_le line 276

    Source documentation

    Only edges incident to changed coordinates contribute to the response. The argument uses the two endpoint degree bounds directly, without a path of intermediate good configurations.

    theorem incident_change_mass_le (K K' H : ι → ι → ℝ) (T : Finset ι)
        (hsym : ∀ i j, H i j = H j i) (hH : ∀ i j, 0 ≤ H i j)
        (d : ℝ) (hrow : ∀ i, (∑ j, H i j) ≤ d)
        (hbound : ∀ i j, |K i j - K' i j| ≤ H i j)
        (heq : ∀ i ∉ T, ∀ j ∉ T, K i j = K' i j) :
        (∑ j, ∑ i, |K i j - K' i j|) ≤ 2 * T.card * d := by
    …
  19. def OAI.JointDickman.siteColumnResponse line 314

    Source documentation

    The unnormalized residual column response for fixed single-site tests.

    noncomputable def siteColumnResponse (E : ι → ι → A → A → ℝ)
        (g : ι → A → ℝ) (x : ι → A) : ℝ :=
    …
  20. theorem OAI.JointDickman.siteColumnResponse_lipschitz_on_good line 318