Theorem: Set.monotone_or_antitone_iff_uIcc
File: Mathlib/Order/Interval/Set/UnorderedInterval.lean

tactic: constructor
state_before: α : Type u_1
β : Type u_2
inst✝¹ : LinearOrder α
inst✝ : LinearOrder β
f : α → β
s : Set α
a a₁ a₂ b b₁ b₂ c d x : α
⊢ Monotone f ∨ Antitone f ↔ ∀ (a b c : α), c ∈ [[a, b]] → f c ∈ [[f a, f b]]
state_after: case mp
α : Type u_1
β : Type u_2
inst✝¹ : LinearOrder α
inst✝ : LinearOrder β
f : α → β
s : Set α
a a₁ a₂ b b₁ b₂ c d x : α
⊢ Monotone f ∨ Antitone f → ∀ (a b c : α), c ∈ [[a, b]] → f c ∈ [[f a, f b]]

case mpr
α : Type u_1
β : Type u_2
inst✝¹ : LinearOrder α
inst✝ : LinearOrder β
f : α → β
s : Set α
a a₁ a₂ b b₁ b₂ c d x : α
⊢ (∀ (a b c : α), c ∈ [[a, b]] → f c ∈ [[f a, f b]]) → Monotone f ∨ Antitone f

tactic: contrapose!
state_before: case mpr
α : Type u_1
β : Type u_2
inst✝¹ : LinearOrder α
inst✝ : LinearOrder β
f : α → β
s : Set α
a a₁ a₂ b b₁ b₂ c d x : α
⊢ (∀ (a b c : α), c ∈ [[a, b]] → f c ∈ [[f a, f b]]) → Monotone f ∨ Antitone f
state_after: case mpr
α : Type u_1
β : Type u_2
inst✝¹ : LinearOrder α
inst✝ : LinearOrder β
f : α → β
s : Set α
a a₁ a₂ b b₁ b₂ c d x : α
⊢ ¬Monotone f ∧ ¬Antitone f → ∃ a b, ∃ c ∈ [[a, b]], f c ∉ [[f a, f b]]

tactic: rw [not_monotone_not_antitone_iff_exists_le_le]
state_before: case mpr
α : Type u_1
β : Type u_2
inst✝¹ : LinearOrder α
inst✝ : LinearOrder β
f : α → β
s : Set α
a a₁ a₂ b b₁ b₂ c d x : α
⊢ ¬Monotone f ∧ ¬Antitone f → ∃ a b, ∃ c ∈ [[a, b]], f c ∉ [[f a, f b]]
state_after: case mpr
α : Type u_1
β : Type u_2
inst✝¹ : LinearOrder α
inst✝ : LinearOrder β
f : α → β
s : Set α
a a₁ a₂ b b₁ b₂ c d x : α
⊢ (∃ a b c, a ≤ b ∧ b ≤ c ∧ (f a < f b ∧ f c < f b ∨ f b < f a ∧ f b < f c)) → ∃ a b, ∃ c ∈ [[a, b]], f c ∉ [[f a, f b]]

tactic: rintro ⟨a, b, c, hab, hbc, ⟨hfab, hfcb⟩ | ⟨hfba, hfbc⟩⟩
state_before: case mpr
α : Type u_1
β : Type u_2
inst✝¹ : LinearOrder α
inst✝ : LinearOrder β
f : α → β
s : Set α
a a₁ a₂ b b₁ b₂ c d x : α
⊢ (∃ a b c, a ≤ b ∧ b ≤ c ∧ (f a < f b ∧ f c < f b ∨ f b < f a ∧ f b < f c)) → ∃ a b, ∃ c ∈ [[a, b]], f c ∉ [[f a, f b]]
state_after: case mpr.intro.intro.intro.intro.intro.inl.intro
α : Type u_1
β : Type u_2
inst✝¹ : LinearOrder α
inst✝ : LinearOrder β
f : α → β
s : Set α
a✝ a₁ a₂ b✝ b₁ b₂ c✝ d x a b c : α
hab : a ≤ b
hbc : b ≤ c
hfab : f a < f b
hfcb : f c < f b
⊢ ∃ a b, ∃ c ∈ [[a, b]], f c ∉ [[f a, f b]]

case mpr.intro.intro.intro.intro.intro.inr.intro
α : Type u_1
β : Type u_2
inst✝¹ : LinearOrder α
inst✝ : LinearOrder β
f : α → β
s : Set α
a✝ a₁ a₂ b✝ b₁ b₂ c✝ d x a b c : α
hab : a ≤ b
hbc : b ≤ c
hfba : f b < f a
hfbc : f b < f c
⊢ ∃ a b, ∃ c ∈ [[a, b]], f c ∉ [[f a, f b]]

tactic: rintro (hf | hf) a b c <;> simp_rw [← Icc_min_max, ← hf.map_min, ← hf.map_max]
state_before: case mp
α : Type u_1
β : Type u_2
inst✝¹ : LinearOrder α
inst✝ : LinearOrder β
f : α → β
s : Set α
a a₁ a₂ b b₁ b₂ c d x : α
⊢ Monotone f ∨ Antitone f → ∀ (a b c : α), c ∈ [[a, b]] → f c ∈ [[f a, f b]]
state_after: case mp.inl
α : Type u_1
β : Type u_2
inst✝¹ : LinearOrder α
inst✝ : LinearOrder β
f : α → β
s : Set α
a✝ a₁ a₂ b✝ b₁ b₂ c✝ d x : α
hf : Monotone f
a b c : α
⊢ c ∈ Icc (min a b) (max a b) → f c ∈ Icc (f (min a b)) (f (max a b))

case mp.inr
α : Type u_1
β : Type u_2
inst✝¹ : LinearOrder α
inst✝ : LinearOrder β
f : α → β
s : Set α
a✝ a₁ a₂ b✝ b₁ b₂ c✝ d x : α
hf : Antitone f
a b c : α
⊢ c ∈ Icc (min a b) (max a b) → f c ∈ Icc (f (max a b)) (f (min a b))

tactic: exacts [fun hc => ⟨hf hc.1, hf hc.2⟩, fun hc => ⟨hf hc.2, hf hc.1⟩]
state_before: case mp.inl
α : Type u_1
β : Type u_2
inst✝¹ : LinearOrder α
inst✝ : LinearOrder β
f : α → β
s : Set α
a✝ a₁ a₂ b✝ b₁ b₂ c✝ d x : α
hf : Monotone f
a b c : α
⊢ c ∈ Icc (min a b) (max a b) → f c ∈ Icc (f (min a b)) (f (max a b))

case mp.inr
α : Type u_1
β : Type u_2
inst✝¹ : LinearOrder α
inst✝ : LinearOrder β
f : α → β
s : Set α
a✝ a₁ a₂ b✝ b₁ b₂ c✝ d x : α
hf : Antitone f
a b c : α
⊢ c ∈ Icc (min a b) (max a b) → f c ∈ Icc (f (max a b)) (f (min a b))
state_after: no goals

tactic: exact ⟨a, c, b, Icc_subset_uIcc ⟨hab, hbc⟩, fun h => h.2.not_lt <| max_lt hfab hfcb⟩
state_before: case mpr.intro.intro.intro.intro.intro.inl.intro
α : Type u_1
β : Type u_2
inst✝¹ : LinearOrder α
inst✝ : LinearOrder β
f : α → β
s : Set α
a✝ a₁ a₂ b✝ b₁ b₂ c✝ d x a b c : α
hab : a ≤ b
hbc : b ≤ c
hfab : f a < f b
hfcb : f c < f b
⊢ ∃ a b, ∃ c ∈ [[a, b]], f c ∉ [[f a, f b]]
state_after: no goals

tactic: exact ⟨a, c, b, Icc_subset_uIcc ⟨hab, hbc⟩, fun h => h.1.not_lt <| lt_min hfba hfbc⟩
state_before: case mpr.intro.intro.intro.intro.intro.inr.intro
α : Type u_1
β : Type u_2
inst✝¹ : LinearOrder α
inst✝ : LinearOrder β
f : α → β
s : Set α
a✝ a₁ a₂ b✝ b₁ b₂ c✝ d x a b c : α
hab : a ≤ b
hbc : b ≤ c
hfba : f b < f a
hfbc : f b < f c
⊢ ∃ a b, ∃ c ∈ [[a, b]], f c ∉ [[f a, f b]]
state_after: no goals