Theorem: toZ_iterate_pred_ge
File: Mathlib/Order/SuccPred/LinearLocallyFinite.lean

tactic: rcases le_or_lt i0 (pred^[n] i0) with h | h
state_before: ι : Type u_1
inst✝³ : LinearOrder ι
inst✝² : SuccOrder ι
inst✝¹ : IsSuccArchimedean ι
inst✝ : PredOrder ι
i0 i : ι
n : ℕ
⊢ -↑n ≤ toZ i0 (pred^[n] i0)
state_after: case inl
ι : Type u_1
inst✝³ : LinearOrder ι
inst✝² : SuccOrder ι
inst✝¹ : IsSuccArchimedean ι
inst✝ : PredOrder ι
i0 i : ι
n : ℕ
h : i0 ≤ pred^[n] i0
⊢ -↑n ≤ toZ i0 (pred^[n] i0)

case inr
ι : Type u_1
inst✝³ : LinearOrder ι
inst✝² : SuccOrder ι
inst✝¹ : IsSuccArchimedean ι
inst✝ : PredOrder ι
i0 i : ι
n : ℕ
h : pred^[n] i0 < i0
⊢ -↑n ≤ toZ i0 (pred^[n] i0)

tactic: have h_eq : pred^[n] i0 = i0 := le_antisymm (pred_iterate_le _ _) h
state_before: case inl
ι : Type u_1
inst✝³ : LinearOrder ι
inst✝² : SuccOrder ι
inst✝¹ : IsSuccArchimedean ι
inst✝ : PredOrder ι
i0 i : ι
n : ℕ
h : i0 ≤ pred^[n] i0
⊢ -↑n ≤ toZ i0 (pred^[n] i0)
state_after: case inl
ι : Type u_1
inst✝³ : LinearOrder ι
inst✝² : SuccOrder ι
inst✝¹ : IsSuccArchimedean ι
inst✝ : PredOrder ι
i0 i : ι
n : ℕ
h : i0 ≤ pred^[n] i0
h_eq : pred^[n] i0 = i0
⊢ -↑n ≤ toZ i0 (pred^[n] i0)

tactic: rw [h_eq, toZ_of_eq]
state_before: case inl
ι : Type u_1
inst✝³ : LinearOrder ι
inst✝² : SuccOrder ι
inst✝¹ : IsSuccArchimedean ι
inst✝ : PredOrder ι
i0 i : ι
n : ℕ
h : i0 ≤ pred^[n] i0
h_eq : pred^[n] i0 = i0
⊢ -↑n ≤ toZ i0 (pred^[n] i0)
state_after: case inl
ι : Type u_1
inst✝³ : LinearOrder ι
inst✝² : SuccOrder ι
inst✝¹ : IsSuccArchimedean ι
inst✝ : PredOrder ι
i0 i : ι
n : ℕ
h : i0 ≤ pred^[n] i0
h_eq : pred^[n] i0 = i0
⊢ -↑n ≤ 0

tactic: omega
state_before: case inl
ι : Type u_1
inst✝³ : LinearOrder ι
inst✝² : SuccOrder ι
inst✝¹ : IsSuccArchimedean ι
inst✝ : PredOrder ι
i0 i : ι
n : ℕ
h : i0 ≤ pred^[n] i0
h_eq : pred^[n] i0 = i0
⊢ -↑n ≤ 0
state_after: no goals

tactic: rw [toZ_of_lt h]
state_before: case inr
ι : Type u_1
inst✝³ : LinearOrder ι
inst✝² : SuccOrder ι
inst✝¹ : IsSuccArchimedean ι
inst✝ : PredOrder ι
i0 i : ι
n : ℕ
h : pred^[n] i0 < i0
⊢ -↑n ≤ toZ i0 (pred^[n] i0)
state_after: case inr
ι : Type u_1
inst✝³ : LinearOrder ι
inst✝² : SuccOrder ι
inst✝¹ : IsSuccArchimedean ι
inst✝ : PredOrder ι
i0 i : ι
n : ℕ
h : pred^[n] i0 < i0
⊢ -↑n ≤ -↑(Nat.find ⋯)

tactic: refine Int.neg_le_neg ?_
state_before: case inr
ι : Type u_1
inst✝³ : LinearOrder ι
inst✝² : SuccOrder ι
inst✝¹ : IsSuccArchimedean ι
inst✝ : PredOrder ι
i0 i : ι
n : ℕ
h : pred^[n] i0 < i0
⊢ -↑n ≤ -↑(Nat.find ⋯)
state_after: case inr
ι : Type u_1
inst✝³ : LinearOrder ι
inst✝² : SuccOrder ι
inst✝¹ : IsSuccArchimedean ι
inst✝ : PredOrder ι
i0 i : ι
n : ℕ
h : pred^[n] i0 < i0
⊢ ↑(Nat.find ⋯) ≤ ↑n

tactic: norm_cast
state_before: case inr
ι : Type u_1
inst✝³ : LinearOrder ι
inst✝² : SuccOrder ι
inst✝¹ : IsSuccArchimedean ι
inst✝ : PredOrder ι
i0 i : ι
n : ℕ
h : pred^[n] i0 < i0
⊢ ↑(Nat.find ⋯) ≤ ↑n
state_after: case inr
ι : Type u_1
inst✝³ : LinearOrder ι
inst✝² : SuccOrder ι
inst✝¹ : IsSuccArchimedean ι
inst✝ : PredOrder ι
i0 i : ι
n : ℕ
h : pred^[n] i0 < i0
⊢ Nat.find ⋯ ≤ n

tactic: exact Nat.find_min' _ rfl
state_before: case inr
ι : Type u_1
inst✝³ : LinearOrder ι
inst✝² : SuccOrder ι
inst✝¹ : IsSuccArchimedean ι
inst✝ : PredOrder ι
i0 i : ι
n : ℕ
h : pred^[n] i0 < i0
⊢ Nat.find ⋯ ≤ n
state_after: no goals