Module: Mathlib.Tactic.ComputeAsymptotics.Multiseries.Corecursion

Goal state before:
pp: case ha₀
α : Type u_1
motive : (Stream'.Seq α → Stream'.Seq α) → Prop
h_step :
  ∀ (op : Stream'.Seq α → Stream'.Seq α),
    motive op →
      ∃ T,
        ∀ (s : Stream'.Seq α),
          (op s).destruct =
            Option.map
              (fun x ↦
                match x with
                | (hd, op') => (hd, ↑op' s.tail))
              (T s.head)
n : ℕ
ih :
  ∀ {op : Stream'.Seq α → Stream'.Seq α},
    motive op → ∀ (s t : Stream'.Seq α), dist s t ≤ 2⁻¹ ^ n → dist (op s) (op t) ≤ 2⁻¹ ^ n
op : Stream'.Seq α → Stream'.Seq α
h_base : motive op
s t : Stream'.Seq α
hn : dist s t ≤ 2⁻¹ ^ (n + 1)
T : Option α → Option (α × Subtype motive)
hT :
  ∀ (s : Stream'.Seq α),
    (op s).destruct =
      Option.map
        (fun x ↦
          match x with
          | (hd, op') => (hd, ↑op' s.tail))
        (T s.head)
⊢ 0 ≤ 2⁻¹

pp: case ha₁
α : Type u_1
motive : (Stream'.Seq α → Stream'.Seq α) → Prop
h_step :
  ∀ (op : Stream'.Seq α → Stream'.Seq α),
    motive op →
      ∃ T,
        ∀ (s : Stream'.Seq α),
          (op s).destruct =
            Option.map
              (fun x ↦
                match x with
                | (hd, op') => (hd, ↑op' s.tail))
              (T s.head)
n : ℕ
ih :
  ∀ {op : Stream'.Seq α → Stream'.Seq α},
    motive op → ∀ (s t : Stream'.Seq α), dist s t ≤ 2⁻¹ ^ n → dist (op s) (op t) ≤ 2⁻¹ ^ n
op : Stream'.Seq α → Stream'.Seq α
h_base : motive op
s t : Stream'.Seq α
hn : dist s t ≤ 2⁻¹ ^ (n + 1)
T : Option α → Option (α × Subtype motive)
hT :
  ∀ (s : Stream'.Seq α),
    (op s).destruct =
      Option.map
        (fun x ↦
          match x with
          | (hd, op') => (hd, ↑op' s.tail))
        (T s.head)
⊢ 2⁻¹ ≤ 1

Tactic:
<;>

Goal state after:
case ha₀
α : Type u_1
motive : (Stream'.Seq α → Stream'.Seq α) → Prop
h_step :
  ∀ (op : Stream'.Seq α → Stream'.Seq α),
    motive op →
      ∃ T,
        ∀ (s : Stream'.Seq α),
          (op s).destruct =
            Option.map
              (fun x ↦
                match x with
                | (hd, op') => (hd, ↑op' s.tail))
              (T s.head)
n : ℕ
ih :
  ∀ {op : Stream'.Seq α → Stream'.Seq α},
    motive op → ∀ (s t : Stream'.Seq α), dist s t ≤ 2⁻¹ ^ n → dist (op s) (op t) ≤ 2⁻¹ ^ n
op : Stream'.Seq α → Stream'.Seq α
h_base : motive op
s t : Stream'.Seq α
hn : dist s t ≤ 2⁻¹ ^ (n + 1)
T : Option α → Option (α × Subtype motive)
hT :
  ∀ (s : Stream'.Seq α),
    (op s).destruct =
      Option.map
        (fun x ↦
          match x with
          | (hd, op') => (hd, ↑op' s.tail))
        (T s.head)
⊢ 0 ≤ 2⁻¹

case ha₁
α : Type u_1
motive : (Stream'.Seq α → Stream'.Seq α) → Prop
h_step :
  ∀ (op : Stream'.Seq α → Stream'.Seq α),
    motive op →
      ∃ T,
        ∀ (s : Stream'.Seq α),
          (op s).destruct =
            Option.map
              (fun x ↦
                match x with
                | (hd, op') => (hd, ↑op' s.tail))
              (T s.head)
n : ℕ
ih :
  ∀ {op : Stream'.Seq α → Stream'.Seq α},
    motive op → ∀ (s t : Stream'.Seq α), dist s t ≤ 2⁻¹ ^ n → dist (op s) (op t) ≤ 2⁻¹ ^ n
op : Stream'.Seq α → Stream'.Seq α
h_base : motive op
s t : Stream'.Seq α
hn : dist s t ≤ 2⁻¹ ^ (n + 1)
T : Option α → Option (α × Subtype motive)
hT :
  ∀ (s : Stream'.Seq α),
    (op s).destruct =
      Option.map
        (fun x ↦
          match x with
          | (hd, op') => (hd, ↑op' s.tail))
        (T s.head)
⊢ 2⁻¹ ≤ 1