Theorem: circleIntegral.integral_sub_inv_smul_sub_smul
File: Mathlib/MeasureTheory/Integral/CircleIntegral.lean

Proof steps:
state_before: E : Type u_1
inst✝² : NormedAddCommGroup E
inst✝¹ : NormedSpace ℂ E
inst✝ : CompleteSpace E
f : ℂ → E
c w : ℂ
R : ℝ
⊢ (∮ (z : ℂ) in C(c, R), (z - w)⁻¹ • (z - w) • f z) = ∮ (z : ℂ) in C(c, R), f z
state_after: case inl
E : Type u_1
inst✝² : NormedAddCommGroup E
inst✝¹ : NormedSpace ℂ E
inst✝ : CompleteSpace E
f : ℂ → E
c w : ℂ
⊢ (∮ (z : ℂ) in C(c, 0), (z - w)⁻¹ • (z - w) • f z) = ∮ (z : ℂ) in C(c, 0), f z

case inr
E : Type u_1
inst✝² : NormedAddCommGroup E
inst✝¹ : NormedSpace ℂ E
inst✝ : CompleteSpace E
f : ℂ → E
c w : ℂ
R : ℝ
hR : R ≠ 0
⊢ (∮ (z : ℂ) in C(c, R), (z - w)⁻¹ • (z - w) • f z) = ∮ (z : ℂ) in C(c, R), f z
tactic: rcases eq_or_ne R 0 with (rfl | hR)
state_before: case inr
E : Type u_1
inst✝² : NormedAddCommGroup E
inst✝¹ : NormedSpace ℂ E
inst✝ : CompleteSpace E
f : ℂ → E
c w : ℂ
R : ℝ
hR : R ≠ 0
⊢ (∮ (z : ℂ) in C(c, R), (z - w)⁻¹ • (z - w) • f z) = ∮ (z : ℂ) in C(c, R), f z
state_after: case inr
E : Type u_1
inst✝² : NormedAddCommGroup E
inst✝¹ : NormedSpace ℂ E
inst✝ : CompleteSpace E
f : ℂ → E
c w : ℂ
R : ℝ
hR : R ≠ 0
this : (circleMap c R ⁻¹' {w}).Countable
⊢ (∮ (z : ℂ) in C(c, R), (z - w)⁻¹ • (z - w) • f z) = ∮ (z : ℂ) in C(c, R), f z
tactic: have : (circleMap c R ⁻¹' {w}).Countable := (countable_singleton _).preimage_circleMap c hR
state_before: case inr
E : Type u_1
inst✝² : NormedAddCommGroup E
inst✝¹ : NormedSpace ℂ E
inst✝ : CompleteSpace E
f : ℂ → E
c w : ℂ
R : ℝ
hR : R ≠ 0
this : (circleMap c R ⁻¹' {w}).Countable
⊢ (∮ (z : ℂ) in C(c, R), (z - w)⁻¹ • (z - w) • f z) = ∮ (z : ℂ) in C(c, R), f z
state_after: case inr
E : Type u_1
inst✝² : NormedAddCommGroup E
inst✝¹ : NormedSpace ℂ E
inst✝ : CompleteSpace E
f : ℂ → E
c w : ℂ
R : ℝ
hR : R ≠ 0
this : (circleMap c R ⁻¹' {w}).Countable
θ : ℝ
hθ : θ ∉ circleMap c R ⁻¹' {w}
_' : θ ∈ Ι 0 (2 * π)
⊢ deriv (circleMap c R) θ • (fun z => (z - w)⁻¹ • (z - w) • f z) (circleMap c R θ) =
    deriv (circleMap c R) θ • (fun z => f z) (circleMap c R θ)
tactic: refine intervalIntegral.integral_congr_ae ((this.ae_not_mem _).mono fun θ hθ _' => ?_)
state_before: case inr
E : Type u_1
inst✝² : NormedAddCommGroup E
inst✝¹ : NormedSpace ℂ E
inst✝ : CompleteSpace E
f : ℂ → E
c w : ℂ
R : ℝ
hR : R ≠ 0
this : (circleMap c R ⁻¹' {w}).Countable
θ : ℝ
hθ : θ ∉ circleMap c R ⁻¹' {w}
_' : θ ∈ Ι 0 (2 * π)
⊢ deriv (circleMap c R) θ • (fun z => (z - w)⁻¹ • (z - w) • f z) (circleMap c R θ) =
    deriv (circleMap c R) θ • (fun z => f z) (circleMap c R θ)
state_after: case inr
E : Type u_1
inst✝² : NormedAddCommGroup E
inst✝¹ : NormedSpace ℂ E
inst✝ : CompleteSpace E
f : ℂ → E
c w : ℂ
R : ℝ
hR : R ≠ 0
this : (circleMap c R ⁻¹' {w}).Countable
θ : ℝ
_' : θ ∈ Ι 0 (2 * π)
hθ : circleMap c R θ ≠ w
⊢ deriv (circleMap c R) θ • (fun z => (z - w)⁻¹ • (z - w) • f z) (circleMap c R θ) =
    deriv (circleMap c R) θ • (fun z => f z) (circleMap c R θ)
tactic: change circleMap c R θ ≠ w at hθ
state_before: case inr
E : Type u_1
inst✝² : NormedAddCommGroup E
inst✝¹ : NormedSpace ℂ E
inst✝ : CompleteSpace E
f : ℂ → E
c w : ℂ
R : ℝ
hR : R ≠ 0
this : (circleMap c R ⁻¹' {w}).Countable
θ : ℝ
_' : θ ∈ Ι 0 (2 * π)
hθ : circleMap c R θ ≠ w
⊢ deriv (circleMap c R) θ • (fun z => (z - w)⁻¹ • (z - w) • f z) (circleMap c R θ) =
    deriv (circleMap c R) θ • (fun z => f z) (circleMap c R θ)
state_after: no goals
tactic: simp only [inv_smul_smul₀ (sub_ne_zero.2 <| hθ)]