Theorem: MeasurableEmbedding.measurable_extend
File: Mathlib/MeasureTheory/MeasurableSpace/Embedding.lean

tactic: refine measurable_of_restrict_of_restrict_compl hf.measurableSet_range ?_ ?_
state_before: α : Type u_1
β : Type u_2
γ : Type u_3
δ : Type u_4
δ' : Type u_5
ι : Sort uι
s t u : Set α
mα : MeasurableSpace α
inst✝¹ : MeasurableSpace β
inst✝ : MeasurableSpace γ
f : α → β
g✝ : β → γ
hf : MeasurableEmbedding f
g : α → γ
g' : β → γ
hg : Measurable g
hg' : Measurable g'
⊢ Measurable (extend f g g')
state_after: case refine_1
α : Type u_1
β : Type u_2
γ : Type u_3
δ : Type u_4
δ' : Type u_5
ι : Sort uι
s t u : Set α
mα : MeasurableSpace α
inst✝¹ : MeasurableSpace β
inst✝ : MeasurableSpace γ
f : α → β
g✝ : β → γ
hf : MeasurableEmbedding f
g : α → γ
g' : β → γ
hg : Measurable g
hg' : Measurable g'
⊢ Measurable ((range f).restrict (extend f g g'))

case refine_2
α : Type u_1
β : Type u_2
γ : Type u_3
δ : Type u_4
δ' : Type u_5
ι : Sort uι
s t u : Set α
mα : MeasurableSpace α
inst✝¹ : MeasurableSpace β
inst✝ : MeasurableSpace γ
f : α → β
g✝ : β → γ
hf : MeasurableEmbedding f
g : α → γ
g' : β → γ
hg : Measurable g
hg' : Measurable g'
⊢ Measurable ((range f)ᶜ.restrict (extend f g g'))

tactic: rw [restrict_extend_range]
state_before: case refine_1
α : Type u_1
β : Type u_2
γ : Type u_3
δ : Type u_4
δ' : Type u_5
ι : Sort uι
s t u : Set α
mα : MeasurableSpace α
inst✝¹ : MeasurableSpace β
inst✝ : MeasurableSpace γ
f : α → β
g✝ : β → γ
hf : MeasurableEmbedding f
g : α → γ
g' : β → γ
hg : Measurable g
hg' : Measurable g'
⊢ Measurable ((range f).restrict (extend f g g'))
state_after: case refine_1
α : Type u_1
β : Type u_2
γ : Type u_3
δ : Type u_4
δ' : Type u_5
ι : Sort uι
s t u : Set α
mα : MeasurableSpace α
inst✝¹ : MeasurableSpace β
inst✝ : MeasurableSpace γ
f : α → β
g✝ : β → γ
hf : MeasurableEmbedding f
g : α → γ
g' : β → γ
hg : Measurable g
hg' : Measurable g'
⊢ Measurable fun x => g (Exists.choose ⋯)

tactic: simpa only [rangeSplitting] using hg.comp hf.measurable_rangeSplitting
state_before: case refine_1
α : Type u_1
β : Type u_2
γ : Type u_3
δ : Type u_4
δ' : Type u_5
ι : Sort uι
s t u : Set α
mα : MeasurableSpace α
inst✝¹ : MeasurableSpace β
inst✝ : MeasurableSpace γ
f : α → β
g✝ : β → γ
hf : MeasurableEmbedding f
g : α → γ
g' : β → γ
hg : Measurable g
hg' : Measurable g'
⊢ Measurable fun x => g (Exists.choose ⋯)
state_after: no goals

tactic: rw [restrict_extend_compl_range]
state_before: case refine_2
α : Type u_1
β : Type u_2
γ : Type u_3
δ : Type u_4
δ' : Type u_5
ι : Sort uι
s t u : Set α
mα : MeasurableSpace α
inst✝¹ : MeasurableSpace β
inst✝ : MeasurableSpace γ
f : α → β
g✝ : β → γ
hf : MeasurableEmbedding f
g : α → γ
g' : β → γ
hg : Measurable g
hg' : Measurable g'
⊢ Measurable ((range f)ᶜ.restrict (extend f g g'))
state_after: case refine_2
α : Type u_1
β : Type u_2
γ : Type u_3
δ : Type u_4
δ' : Type u_5
ι : Sort uι
s t u : Set α
mα : MeasurableSpace α
inst✝¹ : MeasurableSpace β
inst✝ : MeasurableSpace γ
f : α → β
g✝ : β → γ
hf : MeasurableEmbedding f
g : α → γ
g' : β → γ
hg : Measurable g
hg' : Measurable g'
⊢ Measurable (g' ∘ Subtype.val)

tactic: exact hg'.comp measurable_subtype_coe
state_before: case refine_2
α : Type u_1
β : Type u_2
γ : Type u_3
δ : Type u_4
δ' : Type u_5
ι : Sort uι
s t u : Set α
mα : MeasurableSpace α
inst✝¹ : MeasurableSpace β
inst✝ : MeasurableSpace γ
f : α → β
g✝ : β → γ
hf : MeasurableEmbedding f
g : α → γ
g' : β → γ
hg : Measurable g
hg' : Measurable g'
⊢ Measurable (g' ∘ Subtype.val)
state_after: no goals