Module: Mathlib.MeasureTheory.Integral.IntervalIntegral.IntegrationByParts

Goal state before:
pp: a b : ℝ
𝕜 : Type u_1
inst✝⁶ : NontriviallyNormedField 𝕜
inst✝⁵ : NormedAlgebra ℝ 𝕜
E : Type u_2
inst✝⁴ : NormedAddCommGroup E
inst✝³ : NormedSpace 𝕜 E
inst✝² : NormedSpace ℝ E
inst✝¹ : CompleteSpace E
inst✝ : IsScalarTower ℝ 𝕜 E
u u' : ℝ → 𝕜
v v' : ℝ → E
hu : ContinuousOn u [[a, b]]
hv : ContinuousOn v [[a, b]]
huu' : ∀ x ∈ Ioo (min a b) (max a b), HasDerivWithinAt u (u' x) (Ioi x) x
hvv' : ∀ x ∈ Ioo (min a b) (max a b), HasDerivWithinAt v (v' x) (Ioi x) x
hu' : IntervalIntegrable u' volume a b
hv' : IntervalIntegrable v' volume a b
⊢ ∫ (x : ℝ) in a..b, u x • v' x = ∫ (x : ℝ) in a..b, u' x • v x + u x • v' x - u' x • v x

pp: case hf
a b : ℝ
𝕜 : Type u_1
inst✝⁶ : NontriviallyNormedField 𝕜
inst✝⁵ : NormedAlgebra ℝ 𝕜
E : Type u_2
inst✝⁴ : NormedAddCommGroup E
inst✝³ : NormedSpace 𝕜 E
inst✝² : NormedSpace ℝ E
inst✝¹ : CompleteSpace E
inst✝ : IsScalarTower ℝ 𝕜 E
u u' : ℝ → 𝕜
v v' : ℝ → E
hu : ContinuousOn u [[a, b]]
hv : ContinuousOn v [[a, b]]
huu' : ∀ x ∈ Ioo (min a b) (max a b), HasDerivWithinAt u (u' x) (Ioi x) x
hvv' : ∀ x ∈ Ioo (min a b) (max a b), HasDerivWithinAt v (v' x) (Ioi x) x
hu' : IntervalIntegrable u' volume a b
hv' : IntervalIntegrable v' volume a b
⊢ IntervalIntegrable (fun x ↦ u' x • v x + u x • v' x) volume a b

pp: case hg
a b : ℝ
𝕜 : Type u_1
inst✝⁶ : NontriviallyNormedField 𝕜
inst✝⁵ : NormedAlgebra ℝ 𝕜
E : Type u_2
inst✝⁴ : NormedAddCommGroup E
inst✝³ : NormedSpace 𝕜 E
inst✝² : NormedSpace ℝ E
inst✝¹ : CompleteSpace E
inst✝ : IsScalarTower ℝ 𝕜 E
u u' : ℝ → 𝕜
v v' : ℝ → E
hu : ContinuousOn u [[a, b]]
hv : ContinuousOn v [[a, b]]
huu' : ∀ x ∈ Ioo (min a b) (max a b), HasDerivWithinAt u (u' x) (Ioi x) x
hvv' : ∀ x ∈ Ioo (min a b) (max a b), HasDerivWithinAt v (v' x) (Ioi x) x
hu' : IntervalIntegrable u' volume a b
hv' : IntervalIntegrable v' volume a b
⊢ IntervalIntegrable (fun x ↦ u' x • v x) volume a b

Tactic:
· simp_rw [add_sub_cancel_left]

Goal state after:
case hf
a b : ℝ
𝕜 : Type u_1
inst✝⁶ : NontriviallyNormedField 𝕜
inst✝⁵ : NormedAlgebra ℝ 𝕜
E : Type u_2
inst✝⁴ : NormedAddCommGroup E
inst✝³ : NormedSpace 𝕜 E
inst✝² : NormedSpace ℝ E
inst✝¹ : CompleteSpace E
inst✝ : IsScalarTower ℝ 𝕜 E
u u' : ℝ → 𝕜
v v' : ℝ → E
hu : ContinuousOn u [[a, b]]
hv : ContinuousOn v [[a, b]]
huu' : ∀ x ∈ Ioo (min a b) (max a b), HasDerivWithinAt u (u' x) (Ioi x) x
hvv' : ∀ x ∈ Ioo (min a b) (max a b), HasDerivWithinAt v (v' x) (Ioi x) x
hu' : IntervalIntegrable u' volume a b
hv' : IntervalIntegrable v' volume a b
⊢ IntervalIntegrable (fun x ↦ u' x • v x + u x • v' x) volume a b

case hg
a b : ℝ
𝕜 : Type u_1
inst✝⁶ : NontriviallyNormedField 𝕜
inst✝⁵ : NormedAlgebra ℝ 𝕜
E : Type u_2
inst✝⁴ : NormedAddCommGroup E
inst✝³ : NormedSpace 𝕜 E
inst✝² : NormedSpace ℝ E
inst✝¹ : CompleteSpace E
inst✝ : IsScalarTower ℝ 𝕜 E
u u' : ℝ → 𝕜
v v' : ℝ → E
hu : ContinuousOn u [[a, b]]
hv : ContinuousOn v [[a, b]]
huu' : ∀ x ∈ Ioo (min a b) (max a b), HasDerivWithinAt u (u' x) (Ioi x) x
hvv' : ∀ x ∈ Ioo (min a b) (max a b), HasDerivWithinAt v (v' x) (Ioi x) x
hu' : IntervalIntegrable u' volume a b
hv' : IntervalIntegrable v' volume a b
⊢ IntervalIntegrable (fun x ↦ u' x • v x) volume a b