-- Mathlib/MeasureTheory/VectorMeasure/Basic.lean
theorem map_smul {v : VectorMeasure α M} {f : α → β} (c : R) : (c • v).map f = c • v.map f

Proof state:
case neg
α : Type u_1
β : Type u_2
m : MeasurableSpace α
inst✝⁵ : MeasurableSpace β
M : Type u_3
inst✝⁴ : AddCommMonoid M
inst✝³ : TopologicalSpace M
R : Type u_4
inst✝² : Semiring R
inst✝¹ : DistribMulAction R M
inst✝ : ContinuousConstSMul R M
v : VectorMeasure α M
f : α → β
c : R
hf : ¬Measurable f
⊢ 0 = c • 0

Tactic:
ext i

Result:
case neg.h
α : Type u_1
β : Type u_2
m : MeasurableSpace α
inst✝⁵ : MeasurableSpace β
M : Type u_3
inst✝⁴ : AddCommMonoid M
inst✝³ : TopologicalSpace M
R : Type u_4
inst✝² : Semiring R
inst✝¹ : DistribMulAction R M
inst✝ : ContinuousConstSMul R M
v : VectorMeasure α M
f : α → β
c : R
hf : ¬Measurable f
i : Set β
a✝ : MeasurableSet i
⊢ ↑0 i = ↑(c • 0) i

Proof state:
α : Type u_1
β : Type u_2
m : MeasurableSpace α
inst✝⁵ : MeasurableSpace β
M : Type u_3
inst✝⁴ : AddCommMonoid M
inst✝³ : TopologicalSpace M
R : Type u_4
inst✝² : Semiring R
inst✝¹ : DistribMulAction R M
inst✝ : ContinuousConstSMul R M
v : VectorMeasure α M
f : α → β
c : R
⊢ (c • v).map f = c • v.map f

Tactic:
by_cases hf : Measurable f

Result:
case pos
α : Type u_1
β : Type u_2
m : MeasurableSpace α
inst✝⁵ : MeasurableSpace β
M : Type u_3
inst✝⁴ : AddCommMonoid M
inst✝³ : TopologicalSpace M
R : Type u_4
inst✝² : Semiring R
inst✝¹ : DistribMulAction R M
inst✝ : ContinuousConstSMul R M
v : VectorMeasure α M
f : α → β
c : R
hf : Measurable f
⊢ (c • v).map f = c • v.map f

case neg
α : Type u_1
β : Type u_2
m : MeasurableSpace α
inst✝⁵ : MeasurableSpace β
M : Type u_3
inst✝⁴ : AddCommMonoid M
inst✝³ : TopologicalSpace M
R : Type u_4
inst✝² : Semiring R
inst✝¹ : DistribMulAction R M
inst✝ : ContinuousConstSMul R M
v : VectorMeasure α M
f : α → β
c : R
hf : ¬Measurable f
⊢ (c • v).map f = c • v.map f

Proof state:
case neg
α : Type u_1
β : Type u_2
m : MeasurableSpace α
inst✝⁵ : MeasurableSpace β
M : Type u_3
inst✝⁴ : AddCommMonoid M
inst✝³ : TopologicalSpace M
R : Type u_4
inst✝² : Semiring R
inst✝¹ : DistribMulAction R M
inst✝ : ContinuousConstSMul R M
v : VectorMeasure α M
f : α → β
c : R
hf : ¬Measurable f
⊢ (c • v).map f = c • v.map f

Tactic:
simp only [map, dif_neg hf]

Result:
case neg
α : Type u_1
β : Type u_2
m : MeasurableSpace α
inst✝⁵ : MeasurableSpace β
M : Type u_3
inst✝⁴ : AddCommMonoid M
inst✝³ : TopologicalSpace M
R : Type u_4
inst✝² : Semiring R
inst✝¹ : DistribMulAction R M
inst✝ : ContinuousConstSMul R M
v : VectorMeasure α M
f : α → β
c : R
hf : ¬Measurable f
⊢ 0 = c • 0

Proof state:
case pos.h
α : Type u_1
β : Type u_2
m : MeasurableSpace α
inst✝⁵ : MeasurableSpace β
M : Type u_3
inst✝⁴ : AddCommMonoid M
inst✝³ : TopologicalSpace M
R : Type u_4
inst✝² : Semiring R
inst✝¹ : DistribMulAction R M
inst✝ : ContinuousConstSMul R M
v : VectorMeasure α M
f : α → β
c : R
hf : Measurable f
i : Set β
hi : MeasurableSet i
⊢ ↑((c • v).map f) i = ↑(c • v.map f) i

Tactic:
simp [map_apply _ hf hi]

Result:
no goals

Proof state:
case pos
α : Type u_1
β : Type u_2
m : MeasurableSpace α
inst✝⁵ : MeasurableSpace β
M : Type u_3
inst✝⁴ : AddCommMonoid M
inst✝³ : TopologicalSpace M
R : Type u_4
inst✝² : Semiring R
inst✝¹ : DistribMulAction R M
inst✝ : ContinuousConstSMul R M
v : VectorMeasure α M
f : α → β
c : R
hf : Measurable f
⊢ (c • v).map f = c • v.map f

Tactic:
ext i hi

Result:
case pos.h
α : Type u_1
β : Type u_2
m : MeasurableSpace α
inst✝⁵ : MeasurableSpace β
M : Type u_3
inst✝⁴ : AddCommMonoid M
inst✝³ : TopologicalSpace M
R : Type u_4
inst✝² : Semiring R
inst✝¹ : DistribMulAction R M
inst✝ : ContinuousConstSMul R M
v : VectorMeasure α M
f : α → β
c : R
hf : Measurable f
i : Set β
hi : MeasurableSet i
⊢ ↑((c • v).map f) i = ↑(c • v.map f) i

Proof state:
case neg.h
α : Type u_1
β : Type u_2
m : MeasurableSpace α
inst✝⁵ : MeasurableSpace β
M : Type u_3
inst✝⁴ : AddCommMonoid M
inst✝³ : TopologicalSpace M
R : Type u_4
inst✝² : Semiring R
inst✝¹ : DistribMulAction R M
inst✝ : ContinuousConstSMul R M
v : VectorMeasure α M
f : α → β
c : R
hf : ¬Measurable f
i : Set β
a✝ : MeasurableSet i
⊢ ↑0 i = ↑(c • 0) i

Tactic:
simp

Result:
no goals