Theorem: MeasureTheory.SignedMeasure.bddBelow_measureOfNegatives
File: Mathlib/MeasureTheory/Decomposition/SignedHahn.lean

Proof steps:
state_before: α : Type u_1
β : Type u_2
inst✝³ : MeasurableSpace α
M : Type u_3
inst✝² : AddCommMonoid M
inst✝¹ : TopologicalSpace M
inst✝ : OrderedAddCommMonoid M
s : SignedMeasure α
i j : Set α
⊢ BddBelow s.measureOfNegatives
state_after: α : Type u_1
β : Type u_2
inst✝³ : MeasurableSpace α
M : Type u_3
inst✝² : AddCommMonoid M
inst✝¹ : TopologicalSpace M
inst✝ : OrderedAddCommMonoid M
s : SignedMeasure α
i j : Set α
⊢ ∃ x, ∀ x_1 ∈ s.measureOfNegatives, x ≤ x_1
tactic: simp_rw [BddBelow, Set.Nonempty, mem_lowerBounds]
state_before: α : Type u_1
β : Type u_2
inst✝³ : MeasurableSpace α
M : Type u_3
inst✝² : AddCommMonoid M
inst✝¹ : TopologicalSpace M
inst✝ : OrderedAddCommMonoid M
s : SignedMeasure α
i j : Set α
⊢ ∃ x, ∀ x_1 ∈ s.measureOfNegatives, x ≤ x_1
state_after: α : Type u_1
β : Type u_2
inst✝³ : MeasurableSpace α
M : Type u_3
inst✝² : AddCommMonoid M
inst✝¹ : TopologicalSpace M
inst✝ : OrderedAddCommMonoid M
s : SignedMeasure α
i j : Set α
h : ∀ (x : ℝ), ∃ x_1 ∈ s.measureOfNegatives, x_1 < x
⊢ False
tactic: by_contra! h
state_before: α : Type u_1
β : Type u_2
inst✝³ : MeasurableSpace α
M : Type u_3
inst✝² : AddCommMonoid M
inst✝¹ : TopologicalSpace M
inst✝ : OrderedAddCommMonoid M
s : SignedMeasure α
i j : Set α
h : ∀ (x : ℝ), ∃ x_1 ∈ s.measureOfNegatives, x_1 < x
⊢ False
state_after: α : Type u_1
β : Type u_2
inst✝³ : MeasurableSpace α
M : Type u_3
inst✝² : AddCommMonoid M
inst✝¹ : TopologicalSpace M
inst✝ : OrderedAddCommMonoid M
s : SignedMeasure α
i j : Set α
h : ∀ (x : ℝ), ∃ x_1 ∈ s.measureOfNegatives, x_1 < x
h' : ∀ (n : ℕ), ∃ y ∈ s.measureOfNegatives, y < -↑n
⊢ False
tactic: have h' : ∀ n : ℕ, ∃ y : ℝ, y ∈ s.measureOfNegatives ∧ y < -n := fun n => h (-n)
state_before: α : Type u_1
β : Type u_2
inst✝³ : MeasurableSpace α
M : Type u_3
inst✝² : AddCommMonoid M
inst✝¹ : TopologicalSpace M
inst✝ : OrderedAddCommMonoid M
s : SignedMeasure α
i j : Set α
h : ∀ (x : ℝ), ∃ x_1 ∈ s.measureOfNegatives, x_1 < x
h' : ∀ (n : ℕ), ∃ y ∈ s.measureOfNegatives, y < -↑n
⊢ False
state_after: α : Type u_1
β : Type u_2
inst✝³ : MeasurableSpace α
M : Type u_3
inst✝² : AddCommMonoid M
inst✝¹ : TopologicalSpace M
inst✝ : OrderedAddCommMonoid M
s : SignedMeasure α
i j : Set α
h : ∀ (x : ℝ), ∃ x_1 ∈ s.measureOfNegatives, x_1 < x
f : ℕ → ℝ
hf : ∀ (n : ℕ), f n ∈ s.measureOfNegatives ∧ f n < -↑n
⊢ False
tactic: choose f hf using h'
state_before: α : Type u_1
β : Type u_2
inst✝³ : MeasurableSpace α
M : Type u_3
inst✝² : AddCommMonoid M
inst✝¹ : TopologicalSpace M
inst✝ : OrderedAddCommMonoid M
s : SignedMeasure α
i j : Set α
h : ∀ (x : ℝ), ∃ x_1 ∈ s.measureOfNegatives, x_1 < x
f : ℕ → ℝ
hf : ∀ (n : ℕ), f n ∈ s.measureOfNegatives ∧ f n < -↑n
⊢ False
state_after: α : Type u_1
β : Type u_2
inst✝³ : MeasurableSpace α
M : Type u_3
inst✝² : AddCommMonoid M
inst✝¹ : TopologicalSpace M
inst✝ : OrderedAddCommMonoid M
s : SignedMeasure α
i j : Set α
h : ∀ (x : ℝ), ∃ x_1 ∈ s.measureOfNegatives, x_1 < x
f : ℕ → ℝ
hf : ∀ (n : ℕ), f n ∈ s.measureOfNegatives ∧ f n < -↑n
hf' : ∀ (n : ℕ), ∃ B, MeasurableSet B ∧ restrict s B ≤ restrict 0 B ∧ ↑s B < -↑n
⊢ False
tactic: have hf' : ∀ n : ℕ, ∃ B, MeasurableSet B ∧ s ≤[B] 0 ∧ s B < -n := by
    intro n
    rcases hf n with ⟨⟨B, ⟨hB₁, hBr⟩, hB₂⟩, hlt⟩
    exact ⟨B, hB₁, hBr, hB₂.symm ▸ hlt⟩
state_before: α : Type u_1
β : Type u_2
inst✝³ : MeasurableSpace α
M : Type u_3
inst✝² : AddCommMonoid M
inst✝¹ : TopologicalSpace M
inst✝ : OrderedAddCommMonoid M
s : SignedMeasure α
i j : Set α
h : ∀ (x : ℝ), ∃ x_1 ∈ s.measureOfNegatives, x_1 < x
f : ℕ → ℝ
hf : ∀ (n : ℕ), f n ∈ s.measureOfNegatives ∧ f n < -↑n
hf' : ∀ (n : ℕ), ∃ B, MeasurableSet B ∧ restrict s B ≤ restrict 0 B ∧ ↑s B < -↑n
⊢ False
state_after: α : Type u_1
β : Type u_2
inst✝³ : MeasurableSpace α
M : Type u_3
inst✝² : AddCommMonoid M
inst✝¹ : TopologicalSpace M
inst✝ : OrderedAddCommMonoid M
s : SignedMeasure α
i j : Set α
h : ∀ (x : ℝ), ∃ x_1 ∈ s.measureOfNegatives, x_1 < x
f : ℕ → ℝ
hf : ∀ (n : ℕ), f n ∈ s.measureOfNegatives ∧ f n < -↑n
B : ℕ → Set α
hmeas : ∀ (n : ℕ), MeasurableSet (B n)
hr : ∀ (n : ℕ), restrict s (B n) ≤ restrict 0 (B n)
h_lt : ∀ (n : ℕ), ↑s (B n) < -↑n
⊢ False
tactic: choose B hmeas hr h_lt using hf'
state_before: α : Type u_1
β : Type u_2
inst✝³ : MeasurableSpace α
M : Type u_3
inst✝² : AddCommMonoid M
inst✝¹ : TopologicalSpace M
inst✝ : OrderedAddCommMonoid M
s : SignedMeasure α
i j : Set α
h : ∀ (x : ℝ), ∃ x_1 ∈ s.measureOfNegatives, x_1 < x
f : ℕ → ℝ
hf : ∀ (n : ℕ), f n ∈ s.measureOfNegatives ∧ f n < -↑n
B : ℕ → Set α
hmeas : ∀ (n : ℕ), MeasurableSet (B n)
hr : ∀ (n : ℕ), restrict s (B n) ≤ restrict 0 (B n)
h_lt : ∀ (n : ℕ), ↑s (B n) < -↑n
⊢ False
state_after: α : Type u_1
β : Type u_2
inst✝³ : MeasurableSpace α
M : Type u_3
inst✝² : AddCommMonoid M
inst✝¹ : TopologicalSpace M
inst✝ : OrderedAddCommMonoid M
s : SignedMeasure α
i j : Set α
h : ∀ (x : ℝ), ∃ x_1 ∈ s.measureOfNegatives, x_1 < x
f : ℕ → ℝ
hf : ∀ (n : ℕ), f n ∈ s.measureOfNegatives ∧ f n < -↑n
B : ℕ → Set α
hmeas : ∀ (n : ℕ), MeasurableSet (B n)
hr : ∀ (n : ℕ), restrict s (B n) ≤ restrict 0 (B n)
h_lt : ∀ (n : ℕ), ↑s (B n) < -↑n
A : Set α := ⋃ n, B n
hA : A = ⋃ n, B n
⊢ False
tactic: set A := ⋃ n, B n with hA
state_before: α : Type u_1
β : Type u_2
inst✝³ : MeasurableSpace α
M : Type u_3
inst✝² : AddCommMonoid M
inst✝¹ : TopologicalSpace M
inst✝ : OrderedAddCommMonoid M
s : SignedMeasure α
i j : Set α
h : ∀ (x : ℝ), ∃ x_1 ∈ s.measureOfNegatives, x_1 < x
f : ℕ → ℝ
hf : ∀ (n : ℕ), f n ∈ s.measureOfNegatives ∧ f n < -↑n
B : ℕ → Set α
hmeas : ∀ (n : ℕ), MeasurableSet (B n)
hr : ∀ (n : ℕ), restrict s (B n) ≤ restrict 0 (B n)
h_lt : ∀ (n : ℕ), ↑s (B n) < -↑n
A : Set α := ⋃ n, B n
hA : A = ⋃ n, B n
hfalse : ∀ (n : ℕ), ↑s A ≤ -↑n
⊢ False
state_after: case intro
α : Type u_1
β : Type u_2
inst✝³ : MeasurableSpace α
M : Type u_3
inst✝² : AddCommMonoid M
inst✝¹ : TopologicalSpace M
inst✝ : OrderedAddCommMonoid M
s : SignedMeasure α
i j : Set α
h : ∀ (x : ℝ), ∃ x_1 ∈ s.measureOfNegatives, x_1 < x
f : ℕ → ℝ
hf : ∀ (n : ℕ), f n ∈ s.measureOfNegatives ∧ f n < -↑n
B : ℕ → Set α
hmeas : ∀ (n : ℕ), MeasurableSet (B n)
hr : ∀ (n : ℕ), restrict s (B n) ≤ restrict 0 (B n)
h_lt : ∀ (n : ℕ), ↑s (B n) < -↑n
A : Set α := ⋃ n, B n
hA : A = ⋃ n, B n
hfalse : ∀ (n : ℕ), ↑s A ≤ -↑n
n : ℕ
hn : -↑s A < ↑n
⊢ False
tactic: rcases exists_nat_gt (-s A) with ⟨n, hn⟩
state_before: case intro
α : Type u_1
β : Type u_2
inst✝³ : MeasurableSpace α
M : Type u_3
inst✝² : AddCommMonoid M
inst✝¹ : TopologicalSpace M
inst✝ : OrderedAddCommMonoid M
s : SignedMeasure α
i j : Set α
h : ∀ (x : ℝ), ∃ x_1 ∈ s.measureOfNegatives, x_1 < x
f : ℕ → ℝ
hf : ∀ (n : ℕ), f n ∈ s.measureOfNegatives ∧ f n < -↑n
B : ℕ → Set α
hmeas : ∀ (n : ℕ), MeasurableSet (B n)
hr : ∀ (n : ℕ), restrict s (B n) ≤ restrict 0 (B n)
h_lt : ∀ (n : ℕ), ↑s (B n) < -↑n
A : Set α := ⋃ n, B n
hA : A = ⋃ n, B n
hfalse : ∀ (n : ℕ), ↑s A ≤ -↑n
n : ℕ
hn : -↑s A < ↑n
⊢ False
state_after: no goals
tactic: exact lt_irrefl _ ((neg_lt.1 hn).trans_le (hfalse n))