Module: Mathlib.MeasureTheory.VectorMeasure.Decomposition.Hahn

Goal state before:
pp: case right
α : Type u_1
inst✝ : MeasurableSpace α
s : SignedMeasure α
i j : Set α
hi : MeasurableSet i
hj : MeasurableSet j
hi' : (∀ ⦃j : Set α⦄, MeasurableSet j → j ⊆ i → 0 j ≤ s j) ∧ ∀ ⦃j : Set α⦄, MeasurableSet j → j ⊆ iᶜ → s j ≤ 0 j
hj' :
  (∀ ⦃j_1 : Set α⦄, MeasurableSet j_1 → j_1 ⊆ j → 0 j_1 ≤ s j_1) ∧
    ∀ ⦃j_1 : Set α⦄, MeasurableSet j_1 → j_1 ⊆ jᶜ → s j_1 ≤ 0 j_1
⊢ 0 (j ∩ iᶜ) + s (i ∩ jᶜ) = 0

pp: case right.h
α : Type u_1
inst✝ : MeasurableSpace α
s : SignedMeasure α
i j : Set α
hi : MeasurableSet i
hj : MeasurableSet j
hi' : (∀ ⦃j : Set α⦄, MeasurableSet j → j ⊆ i → 0 j ≤ s j) ∧ ∀ ⦃j : Set α⦄, MeasurableSet j → j ⊆ iᶜ → s j ≤ 0 j
hj' :
  (∀ ⦃j_1 : Set α⦄, MeasurableSet j_1 → j_1 ⊆ j → 0 j_1 ≤ s j_1) ∧
    ∀ ⦃j_1 : Set α⦄, MeasurableSet j_1 → j_1 ⊆ jᶜ → s j_1 ≤ 0 j_1
⊢ Disjoint (j ∩ iᶜ) (i ∩ jᶜ)

pp: case right.hA
α : Type u_1
inst✝ : MeasurableSpace α
s : SignedMeasure α
i j : Set α
hi : MeasurableSet i
hj : MeasurableSet j
hi' : (∀ ⦃j : Set α⦄, MeasurableSet j → j ⊆ i → 0 j ≤ s j) ∧ ∀ ⦃j : Set α⦄, MeasurableSet j → j ⊆ iᶜ → s j ≤ 0 j
hj' :
  (∀ ⦃j_1 : Set α⦄, MeasurableSet j_1 → j_1 ⊆ j → 0 j_1 ≤ s j_1) ∧
    ∀ ⦃j_1 : Set α⦄, MeasurableSet j_1 → j_1 ⊆ jᶜ → s j_1 ≤ 0 j_1
⊢ MeasurableSet (j ∩ iᶜ)

pp: case right.hB
α : Type u_1
inst✝ : MeasurableSpace α
s : SignedMeasure α
i j : Set α
hi : MeasurableSet i
hj : MeasurableSet j
hi' : (∀ ⦃j : Set α⦄, MeasurableSet j → j ⊆ i → 0 j ≤ s j) ∧ ∀ ⦃j : Set α⦄, MeasurableSet j → j ⊆ iᶜ → s j ≤ 0 j
hj' :
  (∀ ⦃j_1 : Set α⦄, MeasurableSet j_1 → j_1 ⊆ j → 0 j_1 ≤ s j_1) ∧
    ∀ ⦃j_1 : Set α⦄, MeasurableSet j_1 → j_1 ⊆ jᶜ → s j_1 ≤ 0 j_1
⊢ MeasurableSet (i ∩ jᶜ)

Tactic:
le_antisymm (hj'.2 (hi.inter hj.compl) Set.inter_subset_right)
        (hi'.1 (hi.inter hj.compl) Set.inter_subset_left),

Goal state after:
case right
α : Type u_1
inst✝ : MeasurableSpace α
s : SignedMeasure α
i j : Set α
hi : MeasurableSet i
hj : MeasurableSet j
hi' : (∀ ⦃j : Set α⦄, MeasurableSet j → j ⊆ i → 0 j ≤ s j) ∧ ∀ ⦃j : Set α⦄, MeasurableSet j → j ⊆ iᶜ → s j ≤ 0 j
hj' :
  (∀ ⦃j_1 : Set α⦄, MeasurableSet j_1 → j_1 ⊆ j → 0 j_1 ≤ s j_1) ∧
    ∀ ⦃j_1 : Set α⦄, MeasurableSet j_1 → j_1 ⊆ jᶜ → s j_1 ≤ 0 j_1
⊢ 0 (j ∩ iᶜ) + 0 (i ∩ jᶜ) = 0

case right.h
α : Type u_1
inst✝ : MeasurableSpace α
s : SignedMeasure α
i j : Set α
hi : MeasurableSet i
hj : MeasurableSet j
hi' : (∀ ⦃j : Set α⦄, MeasurableSet j → j ⊆ i → 0 j ≤ s j) ∧ ∀ ⦃j : Set α⦄, MeasurableSet j → j ⊆ iᶜ → s j ≤ 0 j
hj' :
  (∀ ⦃j_1 : Set α⦄, MeasurableSet j_1 → j_1 ⊆ j → 0 j_1 ≤ s j_1) ∧
    ∀ ⦃j_1 : Set α⦄, MeasurableSet j_1 → j_1 ⊆ jᶜ → s j_1 ≤ 0 j_1
⊢ Disjoint (j ∩ iᶜ) (i ∩ jᶜ)

case right.hA
α : Type u_1
inst✝ : MeasurableSpace α
s : SignedMeasure α
i j : Set α
hi : MeasurableSet i
hj : MeasurableSet j
hi' : (∀ ⦃j : Set α⦄, MeasurableSet j → j ⊆ i → 0 j ≤ s j) ∧ ∀ ⦃j : Set α⦄, MeasurableSet j → j ⊆ iᶜ → s j ≤ 0 j
hj' :
  (∀ ⦃j_1 : Set α⦄, MeasurableSet j_1 → j_1 ⊆ j → 0 j_1 ≤ s j_1) ∧
    ∀ ⦃j_1 : Set α⦄, MeasurableSet j_1 → j_1 ⊆ jᶜ → s j_1 ≤ 0 j_1
⊢ MeasurableSet (j ∩ iᶜ)

case right.hB
α : Type u_1
inst✝ : MeasurableSpace α
s : SignedMeasure α
i j : Set α
hi : MeasurableSet i
hj : MeasurableSet j
hi' : (∀ ⦃j : Set α⦄, MeasurableSet j → j ⊆ i → 0 j ≤ s j) ∧ ∀ ⦃j : Set α⦄, MeasurableSet j → j ⊆ iᶜ → s j ≤ 0 j
hj' :
  (∀ ⦃j_1 : Set α⦄, MeasurableSet j_1 → j_1 ⊆ j → 0 j_1 ≤ s j_1) ∧
    ∀ ⦃j_1 : Set α⦄, MeasurableSet j_1 → j_1 ⊆ jᶜ → s j_1 ≤ 0 j_1
⊢ MeasurableSet (i ∩ jᶜ)