Theorem: ProbabilityTheory.setLIntegral_preCDF_fst
File: Mathlib/Probability/Kernel/Disintegration/CondCdf.lean

tactic: have : ∀ r, ∫⁻ x in s, preCDF ρ r x ∂ρ.fst = ∫⁻ x in s, (preCDF ρ r * 1) x ∂ρ.fst := by
  simp only [mul_one, eq_self_iff_true, forall_const]
state_before: α : Type u_1
β : Type u_2
ι : Type u_3
mα : MeasurableSpace α
ρ : Measure (α × ℝ)
r : ℚ
s : Set α
hs : MeasurableSet s
inst✝ : IsFiniteMeasure ρ
⊢ ∫⁻ (x : α) in s, preCDF ρ r x ∂ρ.fst = (ρ.IicSnd ↑r) s
state_after: α : Type u_1
β : Type u_2
ι : Type u_3
mα : MeasurableSpace α
ρ : Measure (α × ℝ)
r : ℚ
s : Set α
hs : MeasurableSet s
inst✝ : IsFiniteMeasure ρ
this : ∀ (r : ℚ), ∫⁻ (x : α) in s, preCDF ρ r x ∂ρ.fst = ∫⁻ (x : α) in s, (preCDF ρ r * 1) x ∂ρ.fst
⊢ ∫⁻ (x : α) in s, preCDF ρ r x ∂ρ.fst = (ρ.IicSnd ↑r) s

tactic: rw [this, ← setLIntegral_withDensity_eq_setLIntegral_mul _ measurable_preCDF _ hs]
state_before: α : Type u_1
β : Type u_2
ι : Type u_3
mα : MeasurableSpace α
ρ : Measure (α × ℝ)
r : ℚ
s : Set α
hs : MeasurableSet s
inst✝ : IsFiniteMeasure ρ
this : ∀ (r : ℚ), ∫⁻ (x : α) in s, preCDF ρ r x ∂ρ.fst = ∫⁻ (x : α) in s, (preCDF ρ r * 1) x ∂ρ.fst
⊢ ∫⁻ (x : α) in s, preCDF ρ r x ∂ρ.fst = (ρ.IicSnd ↑r) s
state_after: α : Type u_1
β : Type u_2
ι : Type u_3
mα : MeasurableSpace α
ρ : Measure (α × ℝ)
r : ℚ
s : Set α
hs : MeasurableSet s
inst✝ : IsFiniteMeasure ρ
this : ∀ (r : ℚ), ∫⁻ (x : α) in s, preCDF ρ r x ∂ρ.fst = ∫⁻ (x : α) in s, (preCDF ρ r * 1) x ∂ρ.fst
⊢ ∫⁻ (x : α) in s, 1 x ∂ρ.fst.withDensity (preCDF ρ r) = (ρ.IicSnd ↑r) s

α : Type u_1
β : Type u_2
ι : Type u_3
mα : MeasurableSpace α
ρ : Measure (α × ℝ)
r : ℚ
s : Set α
hs : MeasurableSet s
inst✝ : IsFiniteMeasure ρ
this : ∀ (r : ℚ), ∫⁻ (x : α) in s, preCDF ρ r x ∂ρ.fst = ∫⁻ (x : α) in s, (preCDF ρ r * 1) x ∂ρ.fst
⊢ Measurable 1

tactic: simp only [mul_one, eq_self_iff_true, forall_const]
state_before: α : Type u_1
β : Type u_2
ι : Type u_3
mα : MeasurableSpace α
ρ : Measure (α × ℝ)
r : ℚ
s : Set α
hs : MeasurableSet s
inst✝ : IsFiniteMeasure ρ
⊢ ∀ (r : ℚ), ∫⁻ (x : α) in s, preCDF ρ r x ∂ρ.fst = ∫⁻ (x : α) in s, (preCDF ρ r * 1) x ∂ρ.fst
state_after: no goals

tactic: simp only [withDensity_preCDF ρ r, Pi.one_apply, lintegral_one, Measure.restrict_apply,
  MeasurableSet.univ, univ_inter]
state_before: α : Type u_1
β : Type u_2
ι : Type u_3
mα : MeasurableSpace α
ρ : Measure (α × ℝ)
r : ℚ
s : Set α
hs : MeasurableSet s
inst✝ : IsFiniteMeasure ρ
this : ∀ (r : ℚ), ∫⁻ (x : α) in s, preCDF ρ r x ∂ρ.fst = ∫⁻ (x : α) in s, (preCDF ρ r * 1) x ∂ρ.fst
⊢ ∫⁻ (x : α) in s, 1 x ∂ρ.fst.withDensity (preCDF ρ r) = (ρ.IicSnd ↑r) s
state_after: no goals

tactic: rw [(_ : (1 : α → ℝ≥0∞) = fun _ ↦ 1)]
state_before: α : Type u_1
β : Type u_2
ι : Type u_3
mα : MeasurableSpace α
ρ : Measure (α × ℝ)
r : ℚ
s : Set α
hs : MeasurableSet s
inst✝ : IsFiniteMeasure ρ
this : ∀ (r : ℚ), ∫⁻ (x : α) in s, preCDF ρ r x ∂ρ.fst = ∫⁻ (x : α) in s, (preCDF ρ r * 1) x ∂ρ.fst
⊢ Measurable 1
state_after: α : Type u_1
β : Type u_2
ι : Type u_3
mα : MeasurableSpace α
ρ : Measure (α × ℝ)
r : ℚ
s : Set α
hs : MeasurableSet s
inst✝ : IsFiniteMeasure ρ
this : ∀ (r : ℚ), ∫⁻ (x : α) in s, preCDF ρ r x ∂ρ.fst = ∫⁻ (x : α) in s, (preCDF ρ r * 1) x ∂ρ.fst
⊢ Measurable fun x => 1

α : Type u_1
β : Type u_2
ι : Type u_3
mα : MeasurableSpace α
ρ : Measure (α × ℝ)
r : ℚ
s : Set α
hs : MeasurableSet s
inst✝ : IsFiniteMeasure ρ
this : ∀ (r : ℚ), ∫⁻ (x : α) in s, preCDF ρ r x ∂ρ.fst = ∫⁻ (x : α) in s, (preCDF ρ r * 1) x ∂ρ.fst
⊢ 1 = fun x => 1

tactic: exacts [measurable_const, rfl]
state_before: α : Type u_1
β : Type u_2
ι : Type u_3
mα : MeasurableSpace α
ρ : Measure (α × ℝ)
r : ℚ
s : Set α
hs : MeasurableSet s
inst✝ : IsFiniteMeasure ρ
this : ∀ (r : ℚ), ∫⁻ (x : α) in s, preCDF ρ r x ∂ρ.fst = ∫⁻ (x : α) in s, (preCDF ρ r * 1) x ∂ρ.fst
⊢ Measurable fun x => 1

α : Type u_1
β : Type u_2
ι : Type u_3
mα : MeasurableSpace α
ρ : Measure (α × ℝ)
r : ℚ
s : Set α
hs : MeasurableSet s
inst✝ : IsFiniteMeasure ρ
this : ∀ (r : ℚ), ∫⁻ (x : α) in s, preCDF ρ r x ∂ρ.fst = ∫⁻ (x : α) in s, (preCDF ρ r * 1) x ∂ρ.fst
⊢ 1 = fun x => 1
state_after: no goals