-- Mathlib/Data/Ordmap/Ordset.lean
theorem Valid'.rotateL {l} {x : α} {r o₁ o₂} (hl : Valid' o₁ l x) (hr : Valid' x r o₂)
    (H1 : ¬size l + size r ≤ 1) (H2 : delta * size l < size r)
    (H3 : 2 * size r ≤ 9 * size l + 5 ∨ size r ≤ 3) : Valid' o₁ (@rotateL α l x r) o₂

Proof state:
case neg.inr
α : Type u_1
inst✝ : Preorder α
l : Ordnode α
x : α
o₁ : WithBot α
o₂ : WithTop α
hl : Valid' o₁ l ↑x
rs : ℕ
rl : Ordnode α
rx : α
rr : Ordnode α
hr : Valid' (↑x) (Ordnode.node rs rl rx rr) o₂
H1 : ¬l.size + (Ordnode.node rs rl rx rr).size ≤ 1
H2 : delta * l.size ≤ rl.size + rr.size
H3 : 2 * (rl.size + rr.size) ≤ 9 * l.size + 3 ∨ rl.size + rr.size ≤ 2
H3_0 : l.size = 0 → rl.size + rr.size ≤ 2
H3p : l.size > 0 → 2 * (rl.size + rr.size) ≤ 9 * l.size + 3
ablem : ∀ {a b : ℕ}, 1 ≤ a → a + b ≤ 2 → b ≤ 1
hlp : l.size > 0 → ¬rl.size + rr.size ≤ 1
h : ¬rl.size < ratio * rr.size
rl0 : rl.size > 0
⊢ l.size = 0 ∧ rl.size = 1 ∧ rr.size ≤ 1 ∨
    0 < l.size ∧
      ratio * rr.size ≤ rl.size ∧
        delta * l.size ≤ rl.size + rr.size ∧ 3 * (rl.size + rr.size) ≤ 16 * l.size + 9 ∧ rl.size ≤ delta * rr.size

Tactic:
rcases Nat.eq_zero_or_pos (size l) with l0 | l0

Result:
case neg.inr.inl
α : Type u_1
inst✝ : Preorder α
l : Ordnode α
x : α
o₁ : WithBot α
o₂ : WithTop α
hl : Valid' o₁ l ↑x
rs : ℕ
rl : Ordnode α
rx : α
rr : Ordnode α
hr : Valid' (↑x) (Ordnode.node rs rl rx rr) o₂
H1 : ¬l.size + (Ordnode.node rs rl rx rr).size ≤ 1
H2 : delta * l.size ≤ rl.size + rr.size
H3 : 2 * (rl.size + rr.size) ≤ 9 * l.size + 3 ∨ rl.size + rr.size ≤ 2
H3_0 : l.size = 0 → rl.size + rr.size ≤ 2
H3p : l.size > 0 → 2 * (rl.size + rr.size) ≤ 9 * l.size + 3
ablem : ∀ {a b : ℕ}, 1 ≤ a → a + b ≤ 2 → b ≤ 1
hlp : l.size > 0 → ¬rl.size + rr.size ≤ 1
h : ¬rl.size < ratio * rr.size
rl0 : rl.size > 0
l0 : l.size = 0
⊢ l.size = 0 ∧ rl.size = 1 ∧ rr.size ≤ 1 ∨
    0 < l.size ∧
      ratio * rr.size ≤ rl.size ∧
        delta * l.size ≤ rl.size + rr.size ∧ 3 * (rl.size + rr.size) ≤ 16 * l.size + 9 ∧ rl.size ≤ delta * rr.size

case neg.inr.inr
α : Type u_1
inst✝ : Preorder α
l : Ordnode α
x : α
o₁ : WithBot α
o₂ : WithTop α
hl : Valid' o₁ l ↑x
rs : ℕ
rl : Ordnode α
rx : α
rr : Ordnode α
hr : Valid' (↑x) (Ordnode.node rs rl rx rr) o₂
H1 : ¬l.size + (Ordnode.node rs rl rx rr).size ≤ 1
H2 : delta * l.size ≤ rl.size + rr.size
H3 : 2 * (rl.size + rr.size) ≤ 9 * l.size + 3 ∨ rl.size + rr.size ≤ 2
H3_0 : l.size = 0 → rl.size + rr.size ≤ 2
H3p : l.size > 0 → 2 * (rl.size + rr.size) ≤ 9 * l.size + 3
ablem : ∀ {a b : ℕ}, 1 ≤ a → a + b ≤ 2 → b ≤ 1
hlp : l.size > 0 → ¬rl.size + rr.size ≤ 1
h : ¬rl.size < ratio * rr.size
rl0 : rl.size > 0
l0 : l.size > 0
⊢ l.size = 0 ∧ rl.size = 1 ∧ rr.size ≤ 1 ∨
    0 < l.size ∧
      ratio * rr.size ≤ rl.size ∧
        delta * l.size ≤ rl.size + rr.size ∧ 3 * (rl.size + rr.size) ≤ 16 * l.size + 9 ∧ rl.size ≤ delta * rr.size

Proof state:
α : Type u_1
inst✝ : Preorder α
l : Ordnode α
x : α
r : Ordnode α
o₁ : WithBot α
o₂ : WithTop α
hl : Valid' o₁ l ↑x
hr : Valid' (↑x) r o₂
H1 : ¬l.size + r.size ≤ 1
H2 : delta * l.size < r.size
H3 : 2 * r.size ≤ 9 * l.size + 5 ∨ r.size ≤ 3
⊢ Valid' o₁ (l.rotateL x r) o₂

Tactic:
obtain - | ⟨rs, rl, rx, rr⟩ := r

Result:
case nil
α : Type u_1
inst✝ : Preorder α
l : Ordnode α
x : α
o₁ : WithBot α
o₂ : WithTop α
hl : Valid' o₁ l ↑x
hr : Valid' (↑x) nil o₂
H1 : ¬l.size + nil.size ≤ 1
H2 : delta * l.size < nil.size
H3 : 2 * nil.size ≤ 9 * l.size + 5 ∨ nil.size ≤ 3
⊢ Valid' o₁ (l.rotateL x nil) o₂

case node
α : Type u_1
inst✝ : Preorder α
l : Ordnode α
x : α
o₁ : WithBot α
o₂ : WithTop α
hl : Valid' o₁ l ↑x
rs : ℕ
rl : Ordnode α
rx : α
rr : Ordnode α
hr : Valid' (↑x) (Ordnode.node rs rl rx rr) o₂
H1 : ¬l.size + (Ordnode.node rs rl rx rr).size ≤ 1
H2 : delta * l.size < (Ordnode.node rs rl rx rr).size
H3 : 2 * (Ordnode.node rs rl rx rr).size ≤ 9 * l.size + 5 ∨ (Ordnode.node rs rl rx rr).size ≤ 3
⊢ Valid' o₁ (l.rotateL x (Ordnode.node rs rl rx rr)) o₂

Proof state:
case pos.inl.inr
α : Type u_1
inst✝ : Preorder α
l : Ordnode α
x : α
o₁ : WithBot α
o₂ : WithTop α
hl : Valid' o₁ l ↑x
rs : ℕ
rl : Ordnode α
rx : α
rr : Ordnode α
hr : Valid' (↑x) (Ordnode.node rs rl rx rr) o₂
H1 : ¬l.size + (Ordnode.node rs rl rx rr).size ≤ 1
H2 : delta * l.size ≤ rl.size + rr.size
H3_0 : l.size = 0 → rl.size + rr.size ≤ 2
H3p : l.size > 0 → 2 * (rl.size + rr.size) ≤ 9 * l.size + 3
ablem : ∀ {a b : ℕ}, 1 ≤ a → a + b ≤ 2 → b ≤ 1
hlp : l.size > 0 → ¬rl.size + rr.size ≤ 1
h : rl.size < ratio * rr.size
rr0 : rr.size > 0
l0 : l.size = 0
H3 : rl.size + rr.size ≤ 2
this : BalancedSz rl.size rr.size
rl0 : rl.size > 0
rr1 : rr.size = 1
⊢ BalancedSz 0 rl.size ∧ BalancedSz (0 + rl.size + 1) rr.size

Tactic:
rw [add_comm] at H3

Result:
case pos.inl.inr
α : Type u_1
inst✝ : Preorder α
l : Ordnode α
x : α
o₁ : WithBot α
o₂ : WithTop α
hl : Valid' o₁ l ↑x
rs : ℕ
rl : Ordnode α
rx : α
rr : Ordnode α
hr : Valid' (↑x) (Ordnode.node rs rl rx rr) o₂
H1 : ¬l.size + (Ordnode.node rs rl rx rr).size ≤ 1
H2 : delta * l.size ≤ rl.size + rr.size
H3_0 : l.size = 0 → rl.size + rr.size ≤ 2
H3p : l.size > 0 → 2 * (rl.size + rr.size) ≤ 9 * l.size + 3
ablem : ∀ {a b : ℕ}, 1 ≤ a → a + b ≤ 2 → b ≤ 1
hlp : l.size > 0 → ¬rl.size + rr.size ≤ 1
h : rl.size < ratio * rr.size
rr0 : rr.size > 0
l0 : l.size = 0
H3 : rr.size + rl.size ≤ 2
this : BalancedSz rl.size rr.size
rl0 : rl.size > 0
rr1 : rr.size = 1
⊢ BalancedSz 0 rl.size ∧ BalancedSz (0 + rl.size + 1) rr.size

Proof state:
α : Type u_1
inst✝ : Preorder α
l : Ordnode α
x : α
o₁ : WithBot α
o₂ : WithTop α
hl : Valid' o₁ l ↑x
rs : ℕ
rl : Ordnode α
rx : α
rr : Ordnode α
hr : Valid' (↑x) (Ordnode.node rs rl rx rr) o₂
H1 : ¬l.size + (Ordnode.node rs rl rx rr).size ≤ 1
H2 : delta * l.size ≤ rl.size + rr.size
H3 : 2 * (rl.size + rr.size) ≤ 9 * l.size + 3 ∨ rl.size + rr.size ≤ 2
l0 : l.size = 0
⊢ rl.size + rr.size ≤ 2

Tactic:
rw [l0] at H3

Result:
α : Type u_1
inst✝ : Preorder α
l : Ordnode α
x : α
o₁ : WithBot α
o₂ : WithTop α
hl : Valid' o₁ l ↑x
rs : ℕ
rl : Ordnode α
rx : α
rr : Ordnode α
hr : Valid' (↑x) (Ordnode.node rs rl rx rr) o₂
H1 : ¬l.size + (Ordnode.node rs rl rx rr).size ≤ 1
H2 : delta * l.size ≤ rl.size + rr.size
H3 : 2 * (rl.size + rr.size) ≤ 9 * 0 + 3 ∨ rl.size + rr.size ≤ 2
l0 : l.size = 0
⊢ rl.size + rr.size ≤ 2

Proof state:
case pos.inl.inr
α : Type u_1
inst✝ : Preorder α
l : Ordnode α
x : α
o₁ : WithBot α
o₂ : WithTop α
hl : Valid' o₁ l ↑x
rs : ℕ
rl : Ordnode α
rx : α
rr : Ordnode α
hr : Valid' (↑x) (Ordnode.node rs rl rx rr) o₂
H1 : ¬l.size + (Ordnode.node rs rl rx rr).size ≤ 1
H2 : delta * l.size ≤ rl.size + rr.size
H3_0 : l.size = 0 → rl.size + rr.size ≤ 2
H3p : l.size > 0 → 2 * (rl.size + rr.size) ≤ 9 * l.size + 3
ablem : ∀ {a b : ℕ}, 1 ≤ a → a + b ≤ 2 → b ≤ 1
hlp : l.size > 0 → ¬rl.size + rr.size ≤ 1
h : rl.size < ratio * rr.size
rr0 : rr.size > 0
l0 : l.size = 0
H3 : rl.size + rr.size ≤ 2
this : BalancedSz rl.size rr.size
rl0 : rl.size > 0
⊢ BalancedSz 0 rl.size ∧ BalancedSz (0 + rl.size + 1) rr.size

Tactic:
have rr1 : size rr = 1 := le_antisymm (ablem rl0 H3) rr0

Result:
case pos.inl.inr
α : Type u_1
inst✝ : Preorder α
l : Ordnode α
x : α
o₁ : WithBot α
o₂ : WithTop α
hl : Valid' o₁ l ↑x
rs : ℕ
rl : Ordnode α
rx : α
rr : Ordnode α
hr : Valid' (↑x) (Ordnode.node rs rl rx rr) o₂
H1 : ¬l.size + (Ordnode.node rs rl rx rr).size ≤ 1
H2 : delta * l.size ≤ rl.size + rr.size
H3_0 : l.size = 0 → rl.size + rr.size ≤ 2
H3p : l.size > 0 → 2 * (rl.size + rr.size) ≤ 9 * l.size + 3
ablem : ∀ {a b : ℕ}, 1 ≤ a → a + b ≤ 2 → b ≤ 1
hlp : l.size > 0 → ¬rl.size + rr.size ≤ 1
h : rl.size < ratio * rr.size
rr0 : rr.size > 0
l0 : l.size = 0
H3 : rl.size + rr.size ≤ 2
this : BalancedSz rl.size rr.size
rl0 : rl.size > 0
rr1 : rr.size = 1
⊢ BalancedSz 0 rl.size ∧ BalancedSz (0 + rl.size + 1) rr.size