OAI/NumberTheory/EgyptianFractions/IntervalSineMargin.lean

GitHub source file

9 declarations, 0 contain sorry, 0 declared as axioms

  1. lemma OAI.Problem337.two_mul_le_sin_pi_mul line 7
  2. theorem OAI.Problem337.sin_pi_mul_lower_of_margin line 14

    Source documentation

    Sine is uniformly bounded below away from both endpoints of the unit interval.

    theorem sin_pi_mul_lower_of_margin {a x : ℝ} (ha : 0 ≤ a)
        (hlo : a ≤ x) (hhi : x ≤ 1-a) : 2*a ≤ Real.sin (Real.pi*x) := by
    …
  3. theorem OAI.Problem337.inner_interval_difference_margin line 25

    Source documentation

    The inner interval stays separated, in both cyclic directions, from its complement.

    theorem inner_interval_difference_margin {δ a t x : ℝ} (_ha : 0 ≤ a)
        (htlo : a ≤ t) (hthi : t ≤ δ-a) (hxlo : δ ≤ x) (hxhi : x ≤ 1) :
        a ≤ x-t ∧ x-t ≤ 1-a := by
    …
  4. theorem OAI.Problem337.inner_interval_sine_lower line 32

    Source documentation

    A geometric-sum denominator for an inner-interval kernel is bounded away from zero at every point outside the target interval.

    theorem inner_interval_sine_lower {δ a t x : ℝ} (ha : 0 ≤ a)
        (htlo : a ≤ t) (hthi : t ≤ δ-a) (hxlo : δ ≤ x) (hxhi : x ≤ 1) :
        2*a ≤ Real.sin (Real.pi*(x-t)) := by
    …
  5. theorem OAI.Problem337.inner_interval_inverse_sin_sq line 39

    Source documentation

    Squaring the reciprocal sine bound gives the standard pointwise Fejer leakage.

    theorem inner_interval_inverse_sin_sq {δ a t x h : ℝ} (ha : 0 < a) (hh : 0 < h)
        (htlo : a ≤ t) (hthi : t ≤ δ-a) (hxlo : δ ≤ x) (hxhi : x ≤ 1) :
        1/(h*(Real.sin (Real.pi*(x-t)))^2) ≤ 1/(4*h*a^2) := by
    …
  6. def OAI.Problem337.innerGridInterval line 50

    Source documentation

    Natural lattice points in a half-open normalized interval.

    def innerGridInterval (q : ℕ) (a b : ℝ) : Finset ℕ :=
    …
  7. lemma OAI.Problem337.innerGridInterval_mem line 53
  8. theorem OAI.Problem337.innerGridInterval_card_bounds line 65

    Source documentation

    Rounding loses at most one lattice point from the expected interval length.

    theorem innerGridInterval_card_bounds (q : ℕ) {a b : ℝ}
        (ha : 0 ≤ a) (hab : a ≤ b) :
        (b-a)*(q : ℝ)-1 ≤ ((innerGridInterval q a b).card : ℝ) ∧
          ((innerGridInterval q a b).card : ℝ) ≤ (b-a)*(q : ℝ)+1 := by
    …

    Mentions: OAI.Problem337.innerGridInterval

  9. theorem OAI.Problem337.innerGridInterval_three_quarters line 86

    Source documentation

    The standard inner three-quarter interval has cardinality close to 3δq/4.

    theorem innerGridInterval_three_quarters (q : ℕ) {δ : ℝ} (hδ : 0 ≤ δ) :
        3*δ*(q : ℝ)/4-1 ≤ ((innerGridInterval q (δ/8) (7*δ/8)).card : ℝ) ∧
          ((innerGridInterval q (δ/8) (7*δ/8)).card : ℝ) ≤ 3*δ*(q : ℝ)/4+1 := by
    …

    Mentions: OAI.Problem337.innerGridInterval