Module: Mathlib.MeasureTheory.VectorMeasure.Variation.Basic

Goal state before:
pp: case refine_1
X : Type u_1
V : Type u_2
mX : MeasurableSpace X
inst✝² : TopologicalSpace V
inst✝¹ : ENormedAddCommMonoid V
inst✝ : T2Space V
μ : VectorMeasure X V
s : Set X
hs : MeasurableSet s
ε : ℝ≥0∞
hε : 0 < ε
hμ : preVariationFun (fun x ↦ ‖μ x‖ₑ) s ≠ ∞
P : Finpartition ⟨s, hs⟩
hP : preVariationFun (fun x ↦ ‖μ x‖ₑ) s ≤ ∑ p ∈ P.parts, (fun x ↦ ‖μ x‖ₑ) ↑p + ε
⊢ ∀ t ∈ Finset.map (Function.Embedding.subtype MeasurableSet) P.parts, t ⊆ s

pp: case refine_2
X : Type u_1
V : Type u_2
mX : MeasurableSpace X
inst✝² : TopologicalSpace V
inst✝¹ : ENormedAddCommMonoid V
inst✝ : T2Space V
μ : VectorMeasure X V
s : Set X
hs : MeasurableSet s
ε : ℝ≥0∞
hε : 0 < ε
hμ : preVariationFun (fun x ↦ ‖μ x‖ₑ) s ≠ ∞
P : Finpartition ⟨s, hs⟩
hP : preVariationFun (fun x ↦ ‖μ x‖ₑ) s ≤ ∑ p ∈ P.parts, (fun x ↦ ‖μ x‖ₑ) ↑p + ε
⊢ (↑(Finset.map (Function.Embedding.subtype MeasurableSet) P.parts)).PairwiseDisjoint id

pp: case refine_3
X : Type u_1
V : Type u_2
mX : MeasurableSpace X
inst✝² : TopologicalSpace V
inst✝¹ : ENormedAddCommMonoid V
inst✝ : T2Space V
μ : VectorMeasure X V
s : Set X
hs : MeasurableSet s
ε : ℝ≥0∞
hε : 0 < ε
hμ : preVariationFun (fun x ↦ ‖μ x‖ₑ) s ≠ ∞
P : Finpartition ⟨s, hs⟩
hP : preVariationFun (fun x ↦ ‖μ x‖ₑ) s ≤ ∑ p ∈ P.parts, (fun x ↦ ‖μ x‖ₑ) ↑p + ε
⊢ ∀ t ∈ Finset.map (Function.Embedding.subtype MeasurableSet) P.parts, MeasurableSet t

pp: case refine_4
X : Type u_1
V : Type u_2
mX : MeasurableSpace X
inst✝² : TopologicalSpace V
inst✝¹ : ENormedAddCommMonoid V
inst✝ : T2Space V
μ : VectorMeasure X V
s : Set X
hs : MeasurableSet s
ε : ℝ≥0∞
hε : 0 < ε
hμ : preVariationFun (fun x ↦ ‖μ x‖ₑ) s ≠ ∞
P : Finpartition ⟨s, hs⟩
hP : preVariationFun (fun x ↦ ‖μ x‖ₑ) s ≤ ∑ p ∈ P.parts, (fun x ↦ ‖μ x‖ₑ) ↑p + ε
⊢ preVariationFun (fun x ↦ ‖μ x‖ₑ) s ≤ ∑ x ∈ Finset.map (Function.Embedding.subtype MeasurableSet) P.parts, ‖μ x‖ₑ + ε

Tactic:
· simp only [mem_map, Function.Embedding.subtype_apply, Subtype.exists, exists_and_right,
      exists_eq_right, forall_exists_index]
    intro t ht h't
    exact P.le h't

Goal state after:
case refine_2
X : Type u_1
V : Type u_2
mX : MeasurableSpace X
inst✝² : TopologicalSpace V
inst✝¹ : ENormedAddCommMonoid V
inst✝ : T2Space V
μ : VectorMeasure X V
s : Set X
hs : MeasurableSet s
ε : ℝ≥0∞
hε : 0 < ε
hμ : preVariationFun (fun x ↦ ‖μ x‖ₑ) s ≠ ∞
P : Finpartition ⟨s, hs⟩
hP : preVariationFun (fun x ↦ ‖μ x‖ₑ) s ≤ ∑ p ∈ P.parts, (fun x ↦ ‖μ x‖ₑ) ↑p + ε
⊢ (↑(Finset.map (Function.Embedding.subtype MeasurableSet) P.parts)).PairwiseDisjoint id

case refine_3
X : Type u_1
V : Type u_2
mX : MeasurableSpace X
inst✝² : TopologicalSpace V
inst✝¹ : ENormedAddCommMonoid V
inst✝ : T2Space V
μ : VectorMeasure X V
s : Set X
hs : MeasurableSet s
ε : ℝ≥0∞
hε : 0 < ε
hμ : preVariationFun (fun x ↦ ‖μ x‖ₑ) s ≠ ∞
P : Finpartition ⟨s, hs⟩
hP : preVariationFun (fun x ↦ ‖μ x‖ₑ) s ≤ ∑ p ∈ P.parts, (fun x ↦ ‖μ x‖ₑ) ↑p + ε
⊢ ∀ t ∈ Finset.map (Function.Embedding.subtype MeasurableSet) P.parts, MeasurableSet t

case refine_4
X : Type u_1
V : Type u_2
mX : MeasurableSpace X
inst✝² : TopologicalSpace V
inst✝¹ : ENormedAddCommMonoid V
inst✝ : T2Space V
μ : VectorMeasure X V
s : Set X
hs : MeasurableSet s
ε : ℝ≥0∞
hε : 0 < ε
hμ : preVariationFun (fun x ↦ ‖μ x‖ₑ) s ≠ ∞
P : Finpartition ⟨s, hs⟩
hP : preVariationFun (fun x ↦ ‖μ x‖ₑ) s ≤ ∑ p ∈ P.parts, (fun x ↦ ‖μ x‖ₑ) ↑p + ε
⊢ preVariationFun (fun x ↦ ‖μ x‖ₑ) s ≤ ∑ x ∈ Finset.map (Function.Embedding.subtype MeasurableSet) P.parts, ‖μ x‖ₑ + ε