OAI/Analysis/MetricEntropy/DirectionBudget.lean

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2 declarations, 0 contain sorry, 0 declared as axioms

The numerical budget for robust directions

The scalar expression in the finite union bound is strictly below one for a sufficiently large prime chosen after the other finite parameters.

  1. theorem OAI.MetricEntropyDuality.direction_bad_event_bound_eq line 18

    Source documentation

    The union-bound expression after substituting w = 2 * D.

    theorem direction_bad_event_bound_eq (D h : ℕ) (u p : ℝ) (hp : p ≠ 0) :
        p ^ D * u ^ (h * (2 * D)) * ((h : ℝ) / p) ^ (2 * D) =
          (((h : ℝ) ^ 2 * u ^ (2 * h)) / p) ^ D := by
    …
  2. theorem OAI.MetricEntropyDuality.direction_bad_event_bound_lt_one line 34

    Source documentation

    The last-prime threshold makes the actual counting bound strictly less than one. No positivity of h or u is needed for this scalar implication.

    theorem direction_bad_event_bound_lt_one {D h u p : ℕ} (hD : 0 < D)
        (hp : h ^ 2 * u ^ (2 * h) < p) :
        (p : ℝ) ^ D * (u : ℝ) ^ (h * (2 * D)) *
            ((h : ℝ) / p) ^ (2 * D) < 1 := by
    …