Equations
- RealAnalysis.mkSubseq a p 0 = Nat.find! fun (x : ℕ) => p (a x)
- RealAnalysis.mkSubseq a p n_2.succ = RealAnalysis.mkSubseq a p n_2 + 1 + Nat.find! fun (x : ℕ) => p (a (RealAnalysis.mkSubseq a p n_2 + 1 + x))
Instances For
theorem
RealAnalysis.exi_fn_series_of_subseq_cover
{a : ℕ → ℝ}
{p : ℝ → Prop}
{σ₁ σ₂ : ℕ → ℕ}
{F : ℝ → ℝ}
(h₁ : Subseq σ₁)
(h₂ : Subseq σ₂)
(h₃ : ∀ (n : ℕ), p (a n) ↔ ∃ (k : ℕ), σ₁ k = n)
(h₄ : ∀ (n : ℕ), ¬p (a n) ↔ ∃ (k : ℕ), σ₂ k = n)
:
∃ (f : ℕ → ℕ) (g : ℕ → ℕ),
(∀ (n : ℕ), f n + g n = n) ∧ (∀ (i j : ℕ), i ≤ j → f i ≤ f j) ∧ (∀ (i j : ℕ), i ≤ j → g i ≤ g j) ∧ (Infp a p → ∀ (n : ℕ), ∃ (k : ℕ), n ≤ f k) ∧ ((Infp a fun (x : ℝ) => ¬p x) → ∀ (n : ℕ), ∃ (k : ℕ), n ≤ g k) ∧ ∀ (n : ℕ),
series (fun (x : ℕ) => F (a x)) n = series (fun (x : ℕ) => F (a (σ₁ x))) (f n) + series (fun (x : ℕ) => F (a (σ₂ x))) (g n)
theorem
RealAnalysis.filter_range_mkSubseq_succ
{a : ℕ → ℝ}
{p : ℝ → Prop}
{n : ℕ}
[hp : DecidablePred p]
(H : Infp a p)
:
List.filter (fun (x : ℕ) => decide (p (a x))) (List.range (mkSubseq a p (n + 1))) = List.filter (fun (x : ℕ) => decide (p (a x))) (List.range (mkSubseq a p n)) ++ [mkSubseq a p n]