simp
case h_ae_eq
f g : ℝ → ℝ
s : Set ℝ
μ : Measure ℝ
hs_meas : MeasurableSet s
hg_int : IntegrableOn g s
hg_nonneg : 0 ≤ᵐ[Measure.restrict μ s] g
hg_nonzero : ∫ (x : ℝ) in s, g x ∂μ ≠ 0
h_int : IntegrableOn (fun x => f x * g x) s
⊢ ∀ᵐ (x : ℝ) ∂Measure.restrict μ s, 0 x ≤ g x → (fun x => f x * g x) x = (fun x => |g x| * f x) x
case h_ae_eq
f g : ℝ → ℝ
s : Set ℝ
μ : Measure ℝ
hs_meas : MeasurableSet s
hg_int : IntegrableOn g s
hg_nonneg : 0 ≤ᵐ[Measure.restrict μ s] g
hg_nonzero : ∫ (x : ℝ) in s, g x ∂μ ≠ 0
h_int : IntegrableOn (fun x => f x * g x) s
⊢ ∀ᵐ (x : ℝ) ∂Measure.restrict μ s, 0 ≤ g x → f x * g x = |g x| * f x