OAI/Combinatorics/SharpThreshold/ProductReindex.lean

GitHub source file

4 declarations, 0 contain sorry, 0 declared as axioms

Reindexing real-valued expectations and Dirichlet energies on finite Boolean products.

  1. theorem OAI.Problem313.Reindex.sum_weight_config line 16

    Source documentation

    A coordinate equivalence preserves each weighted real-valued expectation.

    theorem sum_weight_config (e : ι ≃ κ) (p : ℝ)
        (f : (ι → Bool) → ℝ) (g : (κ → Bool) → ℝ)
        (hfg : ∀ x, g (config e x) = f x) :
        (∑ y, weight p y * g y) = ∑ x, weight p x * f x := by
    …

    Mentions: OAI.Problem313.Reindex.config, OAI.Problem313.Reindex.weight

  2. theorem OAI.Problem313.Reindex.coordinate_energy_config line 27

    Source documentation

    The squared energy at a single coordinate is preserved by reindexing.

    theorem coordinate_energy_config
        (e : ι ≃ κ) (p : ℝ) (f : (ι → Bool) → ℝ) (g : (κ → Bool) → ℝ)
        (hfg : ∀ x, g (config e x) = f x) (i : ι) :
        (∑ y, weight p y *
          (g (Function.update y (e i) true) - g (Function.update y (e i) false)) ^ 2) =
          ∑ x, weight p x *
            (f (Function.update x i true) - f (Function.update x i false)) ^ 2 := by
    …

    Mentions: OAI.Problem313.Reindex.config, OAI.Problem313.Reindex.weight

  3. theorem OAI.Problem313.Reindex.energy_config line 39

    Source documentation

    The full Dirichlet energy is invariant under a finite coordinate equivalence.

    theorem energy_config
        (e : ι ≃ κ) (p : ℝ) (f : (ι → Bool) → ℝ) (g : (κ → Bool) → ℝ)
        (hfg : ∀ x, g (config e x) = f x) :
        (∑ j, ∑ y, weight p y *
          (g (Function.update y j true) - g (Function.update y j false)) ^ 2) =
          ∑ i, ∑ x, weight p x *
            (f (Function.update x i true) - f (Function.update x i false)) ^ 2 := by
    …

    Mentions: OAI.Problem313.Reindex.config, OAI.Problem313.Reindex.weight

  4. theorem OAI.Problem313.Reindex.centered_sum_config line 52

    Source documentation

    Centered second moments are invariant, for any specified center.

    theorem centered_sum_config (e : ι ≃ κ) (p c : ℝ)
        (f : (ι → Bool) → ℝ) (g : (κ → Bool) → ℝ)
        (hfg : ∀ x, g (config e x) = f x) :
        (∑ y, weight p y * (g y - c) ^ 2) =
          ∑ x, weight p x * (f x - c) ^ 2 := by
    …

    Mentions: OAI.Problem313.Reindex.config, OAI.Problem313.Reindex.weight