Theorem: Monotone.biUnion_Ico_Ioc_map_succ
File: Mathlib/Order/SuccPred/IntervalSucc.lean

tactic: rcases le_total n m with hnm | hmn
state_before: α : Type u_1
β : Type u_2
inst✝³ : LinearOrder α
inst✝² : SuccOrder α
inst✝¹ : IsSuccArchimedean α
inst✝ : LinearOrder β
f : α → β
hf : Monotone f
m n : α
⊢ ⋃ i ∈ Ico m n, Ioc (f i) (f (succ i)) = Ioc (f m) (f n)
state_after: case inl
α : Type u_1
β : Type u_2
inst✝³ : LinearOrder α
inst✝² : SuccOrder α
inst✝¹ : IsSuccArchimedean α
inst✝ : LinearOrder β
f : α → β
hf : Monotone f
m n : α
hnm : n ≤ m
⊢ ⋃ i ∈ Ico m n, Ioc (f i) (f (succ i)) = Ioc (f m) (f n)

case inr
α : Type u_1
β : Type u_2
inst✝³ : LinearOrder α
inst✝² : SuccOrder α
inst✝¹ : IsSuccArchimedean α
inst✝ : LinearOrder β
f : α → β
hf : Monotone f
m n : α
hmn : m ≤ n
⊢ ⋃ i ∈ Ico m n, Ioc (f i) (f (succ i)) = Ioc (f m) (f n)

tactic: rw [Ico_eq_empty_of_le hnm, Ioc_eq_empty_of_le (hf hnm), biUnion_empty]
state_before: case inl
α : Type u_1
β : Type u_2
inst✝³ : LinearOrder α
inst✝² : SuccOrder α
inst✝¹ : IsSuccArchimedean α
inst✝ : LinearOrder β
f : α → β
hf : Monotone f
m n : α
hnm : n ≤ m
⊢ ⋃ i ∈ Ico m n, Ioc (f i) (f (succ i)) = Ioc (f m) (f n)
state_after: no goals

tactic: refine Succ.rec ?_ ?_ hmn
state_before: case inr
α : Type u_1
β : Type u_2
inst✝³ : LinearOrder α
inst✝² : SuccOrder α
inst✝¹ : IsSuccArchimedean α
inst✝ : LinearOrder β
f : α → β
hf : Monotone f
m n : α
hmn : m ≤ n
⊢ ⋃ i ∈ Ico m n, Ioc (f i) (f (succ i)) = Ioc (f m) (f n)
state_after: case inr.refine_1
α : Type u_1
β : Type u_2
inst✝³ : LinearOrder α
inst✝² : SuccOrder α
inst✝¹ : IsSuccArchimedean α
inst✝ : LinearOrder β
f : α → β
hf : Monotone f
m n : α
hmn : m ≤ n
⊢ ⋃ i ∈ Ico m m, Ioc (f i) (f (succ i)) = Ioc (f m) (f m)

case inr.refine_2
α : Type u_1
β : Type u_2
inst✝³ : LinearOrder α
inst✝² : SuccOrder α
inst✝¹ : IsSuccArchimedean α
inst✝ : LinearOrder β
f : α → β
hf : Monotone f
m n : α
hmn : m ≤ n
⊢ ∀ (n : α),
    m ≤ n →
      ⋃ i ∈ Ico m n, Ioc (f i) (f (succ i)) = Ioc (f m) (f n) →
        ⋃ i ∈ Ico m (succ n), Ioc (f i) (f (succ i)) = Ioc (f m) (f (succ n))

tactic: simp only [Ioc_self, Ico_self, biUnion_empty]
state_before: case inr.refine_1
α : Type u_1
β : Type u_2
inst✝³ : LinearOrder α
inst✝² : SuccOrder α
inst✝¹ : IsSuccArchimedean α
inst✝ : LinearOrder β
f : α → β
hf : Monotone f
m n : α
hmn : m ≤ n
⊢ ⋃ i ∈ Ico m m, Ioc (f i) (f (succ i)) = Ioc (f m) (f m)
state_after: no goals

tactic: intro k hmk ihk
state_before: case inr.refine_2
α : Type u_1
β : Type u_2
inst✝³ : LinearOrder α
inst✝² : SuccOrder α
inst✝¹ : IsSuccArchimedean α
inst✝ : LinearOrder β
f : α → β
hf : Monotone f
m n : α
hmn : m ≤ n
⊢ ∀ (n : α),
    m ≤ n →
      ⋃ i ∈ Ico m n, Ioc (f i) (f (succ i)) = Ioc (f m) (f n) →
        ⋃ i ∈ Ico m (succ n), Ioc (f i) (f (succ i)) = Ioc (f m) (f (succ n))
state_after: case inr.refine_2
α : Type u_1
β : Type u_2
inst✝³ : LinearOrder α
inst✝² : SuccOrder α
inst✝¹ : IsSuccArchimedean α
inst✝ : LinearOrder β
f : α → β
hf : Monotone f
m n : α
hmn : m ≤ n
k : α
hmk : m ≤ k
ihk : ⋃ i ∈ Ico m k, Ioc (f i) (f (succ i)) = Ioc (f m) (f k)
⊢ ⋃ i ∈ Ico m (succ k), Ioc (f i) (f (succ i)) = Ioc (f m) (f (succ k))

tactic: rw [← Ioc_union_Ioc_eq_Ioc (hf hmk) (hf <| le_succ _), union_comm, ← ihk]
state_before: case inr.refine_2
α : Type u_1
β : Type u_2
inst✝³ : LinearOrder α
inst✝² : SuccOrder α
inst✝¹ : IsSuccArchimedean α
inst✝ : LinearOrder β
f : α → β
hf : Monotone f
m n : α
hmn : m ≤ n
k : α
hmk : m ≤ k
ihk : ⋃ i ∈ Ico m k, Ioc (f i) (f (succ i)) = Ioc (f m) (f k)
⊢ ⋃ i ∈ Ico m (succ k), Ioc (f i) (f (succ i)) = Ioc (f m) (f (succ k))
state_after: case inr.refine_2
α : Type u_1
β : Type u_2
inst✝³ : LinearOrder α
inst✝² : SuccOrder α
inst✝¹ : IsSuccArchimedean α
inst✝ : LinearOrder β
f : α → β
hf : Monotone f
m n : α
hmn : m ≤ n
k : α
hmk : m ≤ k
ihk : ⋃ i ∈ Ico m k, Ioc (f i) (f (succ i)) = Ioc (f m) (f k)
⊢ ⋃ i ∈ Ico m (succ k), Ioc (f i) (f (succ i)) = Ioc (f k) (f (succ k)) ∪ ⋃ i ∈ Ico m k, Ioc (f i) (f (succ i))

tactic: by_cases hk : IsMax k
state_before: case inr.refine_2
α : Type u_1
β : Type u_2
inst✝³ : LinearOrder α
inst✝² : SuccOrder α
inst✝¹ : IsSuccArchimedean α
inst✝ : LinearOrder β
f : α → β
hf : Monotone f
m n : α
hmn : m ≤ n
k : α
hmk : m ≤ k
ihk : ⋃ i ∈ Ico m k, Ioc (f i) (f (succ i)) = Ioc (f m) (f k)
⊢ ⋃ i ∈ Ico m (succ k), Ioc (f i) (f (succ i)) = Ioc (f k) (f (succ k)) ∪ ⋃ i ∈ Ico m k, Ioc (f i) (f (succ i))
state_after: case pos
α : Type u_1
β : Type u_2
inst✝³ : LinearOrder α
inst✝² : SuccOrder α
inst✝¹ : IsSuccArchimedean α
inst✝ : LinearOrder β
f : α → β
hf : Monotone f
m n : α
hmn : m ≤ n
k : α
hmk : m ≤ k
ihk : ⋃ i ∈ Ico m k, Ioc (f i) (f (succ i)) = Ioc (f m) (f k)
hk : IsMax k
⊢ ⋃ i ∈ Ico m (succ k), Ioc (f i) (f (succ i)) = Ioc (f k) (f (succ k)) ∪ ⋃ i ∈ Ico m k, Ioc (f i) (f (succ i))

case neg
α : Type u_1
β : Type u_2
inst✝³ : LinearOrder α
inst✝² : SuccOrder α
inst✝¹ : IsSuccArchimedean α
inst✝ : LinearOrder β
f : α → β
hf : Monotone f
m n : α
hmn : m ≤ n
k : α
hmk : m ≤ k
ihk : ⋃ i ∈ Ico m k, Ioc (f i) (f (succ i)) = Ioc (f m) (f k)
hk : ¬IsMax k
⊢ ⋃ i ∈ Ico m (succ k), Ioc (f i) (f (succ i)) = Ioc (f k) (f (succ k)) ∪ ⋃ i ∈ Ico m k, Ioc (f i) (f (succ i))

tactic: rw [hk.succ_eq, Ioc_self, empty_union]
state_before: case pos
α : Type u_1
β : Type u_2
inst✝³ : LinearOrder α
inst✝² : SuccOrder α
inst✝¹ : IsSuccArchimedean α
inst✝ : LinearOrder β
f : α → β
hf : Monotone f
m n : α
hmn : m ≤ n
k : α
hmk : m ≤ k
ihk : ⋃ i ∈ Ico m k, Ioc (f i) (f (succ i)) = Ioc (f m) (f k)
hk : IsMax k
⊢ ⋃ i ∈ Ico m (succ k), Ioc (f i) (f (succ i)) = Ioc (f k) (f (succ k)) ∪ ⋃ i ∈ Ico m k, Ioc (f i) (f (succ i))
state_after: no goals

tactic: rw [Ico_succ_right_eq_insert_of_not_isMax hmk hk, biUnion_insert]
state_before: case neg
α : Type u_1
β : Type u_2
inst✝³ : LinearOrder α
inst✝² : SuccOrder α
inst✝¹ : IsSuccArchimedean α
inst✝ : LinearOrder β
f : α → β
hf : Monotone f
m n : α
hmn : m ≤ n
k : α
hmk : m ≤ k
ihk : ⋃ i ∈ Ico m k, Ioc (f i) (f (succ i)) = Ioc (f m) (f k)
hk : ¬IsMax k
⊢ ⋃ i ∈ Ico m (succ k), Ioc (f i) (f (succ i)) = Ioc (f k) (f (succ k)) ∪ ⋃ i ∈ Ico m k, Ioc (f i) (f (succ i))
state_after: no goals