-- Mathlib/Analysis/BoxIntegral/Partition/Tagged.lean
theorem IsSubordinate.disjUnion [Fintype ι] (h₁ : IsSubordinate π₁ r) (h₂ : IsSubordinate π₂ r)
    (h : Disjoint π₁.iUnion π₂.iUnion) : IsSubordinate (π₁.disjUnion π₂ h) r

Proof state:
case refine_2
ι : Type u_1
I : Box ι
π₁ π₂ : TaggedPrepartition I
r : (ι → ℝ) → ↑(Set.Ioi 0)
inst✝ : Fintype ι
h₁ : π₁.IsSubordinate r
h₂ : π₂.IsSubordinate r
h : Disjoint π₁.iUnion π₂.iUnion
J : Box ι
hJ✝ : J ∈ π₁.disjUnion π₂ h
hJ : J ∈ π₂.boxes
⊢ Box.Icc J ⊆ closedBall ((π₁.disjUnion π₂ h).tag J) ↑(r ((π₁.disjUnion π₂ h).tag J))

Tactic:
rw [disjUnion_tag_of_mem_right _ hJ]

Result:
case refine_2
ι : Type u_1
I : Box ι
π₁ π₂ : TaggedPrepartition I
r : (ι → ℝ) → ↑(Set.Ioi 0)
inst✝ : Fintype ι
h₁ : π₁.IsSubordinate r
h₂ : π₂.IsSubordinate r
h : Disjoint π₁.iUnion π₂.iUnion
J : Box ι
hJ✝ : J ∈ π₁.disjUnion π₂ h
hJ : J ∈ π₂.boxes
⊢ Box.Icc J ⊆ closedBall (π₂.tag J) ↑(r (π₂.tag J))

Proof state:
ι : Type u_1
I : Box ι
π₁ π₂ : TaggedPrepartition I
r : (ι → ℝ) → ↑(Set.Ioi 0)
inst✝ : Fintype ι
h₁ : π₁.IsSubordinate r
h₂ : π₂.IsSubordinate r
h : Disjoint π₁.iUnion π₂.iUnion
⊢ (π₁.disjUnion π₂ h).IsSubordinate r

Tactic:
refine fun J hJ => (Finset.mem_union.1 hJ).elim (fun hJ => ?_) fun hJ => ?_

Result:
case refine_1
ι : Type u_1
I : Box ι
π₁ π₂ : TaggedPrepartition I
r : (ι → ℝ) → ↑(Set.Ioi 0)
inst✝ : Fintype ι
h₁ : π₁.IsSubordinate r
h₂ : π₂.IsSubordinate r
h : Disjoint π₁.iUnion π₂.iUnion
J : Box ι
hJ✝ : J ∈ π₁.disjUnion π₂ h
hJ : J ∈ π₁.boxes
⊢ Box.Icc J ⊆ closedBall ((π₁.disjUnion π₂ h).tag J) ↑(r ((π₁.disjUnion π₂ h).tag J))

case refine_2
ι : Type u_1
I : Box ι
π₁ π₂ : TaggedPrepartition I
r : (ι → ℝ) → ↑(Set.Ioi 0)
inst✝ : Fintype ι
h₁ : π₁.IsSubordinate r
h₂ : π₂.IsSubordinate r
h : Disjoint π₁.iUnion π₂.iUnion
J : Box ι
hJ✝ : J ∈ π₁.disjUnion π₂ h
hJ : J ∈ π₂.boxes
⊢ Box.Icc J ⊆ closedBall ((π₁.disjUnion π₂ h).tag J) ↑(r ((π₁.disjUnion π₂ h).tag J))

Proof state:
case refine_1
ι : Type u_1
I : Box ι
π₁ π₂ : TaggedPrepartition I
r : (ι → ℝ) → ↑(Set.Ioi 0)
inst✝ : Fintype ι
h₁ : π₁.IsSubordinate r
h₂ : π₂.IsSubordinate r
h : Disjoint π₁.iUnion π₂.iUnion
J : Box ι
hJ✝ : J ∈ π₁.disjUnion π₂ h
hJ : J ∈ π₁.boxes
⊢ Box.Icc J ⊆ closedBall ((π₁.disjUnion π₂ h).tag J) ↑(r ((π₁.disjUnion π₂ h).tag J))

Tactic:
rw [disjUnion_tag_of_mem_left _ hJ]

Result:
case refine_1
ι : Type u_1
I : Box ι
π₁ π₂ : TaggedPrepartition I
r : (ι → ℝ) → ↑(Set.Ioi 0)
inst✝ : Fintype ι
h₁ : π₁.IsSubordinate r
h₂ : π₂.IsSubordinate r
h : Disjoint π₁.iUnion π₂.iUnion
J : Box ι
hJ✝ : J ∈ π₁.disjUnion π₂ h
hJ : J ∈ π₁.boxes
⊢ Box.Icc J ⊆ closedBall (π₁.tag J) ↑(r (π₁.tag J))

Proof state:
case refine_2
ι : Type u_1
I : Box ι
π₁ π₂ : TaggedPrepartition I
r : (ι → ℝ) → ↑(Set.Ioi 0)
inst✝ : Fintype ι
h₁ : π₁.IsSubordinate r
h₂ : π₂.IsSubordinate r
h : Disjoint π₁.iUnion π₂.iUnion
J : Box ι
hJ✝ : J ∈ π₁.disjUnion π₂ h
hJ : J ∈ π₂.boxes
⊢ Box.Icc J ⊆ closedBall (π₂.tag J) ↑(r (π₂.tag J))

Tactic:
exact h₂ _ hJ

Result:
no goals

Proof state:
case refine_1
ι : Type u_1
I : Box ι
π₁ π₂ : TaggedPrepartition I
r : (ι → ℝ) → ↑(Set.Ioi 0)
inst✝ : Fintype ι
h₁ : π₁.IsSubordinate r
h₂ : π₂.IsSubordinate r
h : Disjoint π₁.iUnion π₂.iUnion
J : Box ι
hJ✝ : J ∈ π₁.disjUnion π₂ h
hJ : J ∈ π₁.boxes
⊢ Box.Icc J ⊆ closedBall (π₁.tag J) ↑(r (π₁.tag J))

Tactic:
exact h₁ _ hJ

Result:
no goals