-- Mathlib/Probability/Kernel/Disintegration/Density.lean
lemma densityProcess_mono_kernel_left {κ' : Kernel α (γ × β)} (hκκ' : κ ≤ κ')
    (hκ'ν : fst κ' ≤ ν) (n : ℕ) (a : α) (x : γ) (s : Set β) :
    densityProcess κ ν n a x s ≤ densityProcess κ' ν n a x s

Proof state:
case pos
α : Type u_1
β : Type u_2
γ : Type u_3
mα : MeasurableSpace α
mβ : MeasurableSpace β
mγ : MeasurableSpace γ
inst✝ : CountablyGenerated γ
κ : Kernel α (γ × β)
ν : Kernel α γ
κ' : Kernel α (γ × β)
hκκ' : κ ≤ κ'
hκ'ν : κ'.fst ≤ ν
n : ℕ
a : α
x : γ
s : Set β
h0 : (ν a) (countablePartitionSet n x) = 0
⊢ ((κ a) (countablePartitionSet n x ×ˢ s)).toReal / ENNReal.toReal 0 ≤
    ((κ' a) (countablePartitionSet n x ×ˢ s)).toReal / ENNReal.toReal 0

Tactic:
simp

Result:
no goals

Proof state:
case neg.hb
α : Type u_1
β : Type u_2
γ : Type u_3
mα : MeasurableSpace α
mβ : MeasurableSpace β
mγ : MeasurableSpace γ
inst✝ : CountablyGenerated γ
κ : Kernel α (γ × β)
ν : Kernel α γ
κ' : Kernel α (γ × β)
hκκ' : κ ≤ κ'
hκ'ν : κ'.fst ≤ ν
n : ℕ
a : α
x : γ
s : Set β
h0 : ¬(ν a) (countablePartitionSet n x) = 0
h_le : (κ' a) (countablePartitionSet n x ×ˢ s) ≤ (ν a) (countablePartitionSet n x)
⊢ (κ' a) (countablePartitionSet n x ×ˢ s) / (ν a) (countablePartitionSet n x) ≠ ⊤

Tactic:
simp only [ne_eq, ENNReal.div_eq_top, h0, and_false, false_or, not_and, not_not]

Result:
case neg.hb
α : Type u_1
β : Type u_2
γ : Type u_3
mα : MeasurableSpace α
mβ : MeasurableSpace β
mγ : MeasurableSpace γ
inst✝ : CountablyGenerated γ
κ : Kernel α (γ × β)
ν : Kernel α γ
κ' : Kernel α (γ × β)
hκκ' : κ ≤ κ'
hκ'ν : κ'.fst ≤ ν
n : ℕ
a : α
x : γ
s : Set β
h0 : ¬(ν a) (countablePartitionSet n x) = 0
h_le : (κ' a) (countablePartitionSet n x ×ˢ s) ≤ (ν a) (countablePartitionSet n x)
⊢ (κ' a) (countablePartitionSet n x ×ˢ s) = ⊤ → (ν a) (countablePartitionSet n x) = ⊤

Proof state:
α : Type u_1
β : Type u_2
γ : Type u_3
mα : MeasurableSpace α
mβ : MeasurableSpace β
mγ : MeasurableSpace γ
inst✝ : CountablyGenerated γ
κ : Kernel α (γ × β)
ν : Kernel α γ
κ' : Kernel α (γ × β)
hκκ' : κ ≤ κ'
hκ'ν : κ'.fst ≤ ν
n : ℕ
a : α
x : γ
s : Set β
⊢ κ.densityProcess ν n a x s ≤ κ'.densityProcess ν n a x s

Tactic:
unfold densityProcess

Result:
α : Type u_1
β : Type u_2
γ : Type u_3
mα : MeasurableSpace α
mβ : MeasurableSpace β
mγ : MeasurableSpace γ
inst✝ : CountablyGenerated γ
κ : Kernel α (γ × β)
ν : Kernel α γ
κ' : Kernel α (γ × β)
hκκ' : κ ≤ κ'
hκ'ν : κ'.fst ≤ ν
n : ℕ
a : α
x : γ
s : Set β
⊢ ((κ a) (countablePartitionSet n x ×ˢ s) / (ν a) (countablePartitionSet n x)).toReal ≤
    ((κ' a) (countablePartitionSet n x ×ˢ s) / (ν a) (countablePartitionSet n x)).toReal

Proof state:
case pos
α : Type u_1
β : Type u_2
γ : Type u_3
mα : MeasurableSpace α
mβ : MeasurableSpace β
mγ : MeasurableSpace γ
inst✝ : CountablyGenerated γ
κ : Kernel α (γ × β)
ν : Kernel α γ
κ' : Kernel α (γ × β)
hκκ' : κ ≤ κ'
hκ'ν : κ'.fst ≤ ν
n : ℕ
a : α
x : γ
s : Set β
h0 : (ν a) (countablePartitionSet n x) = 0
⊢ ((κ a) (countablePartitionSet n x ×ˢ s) / (ν a) (countablePartitionSet n x)).toReal ≤
    ((κ' a) (countablePartitionSet n x ×ˢ s) / (ν a) (countablePartitionSet n x)).toReal

Tactic:
rw [h0, ENNReal.toReal_div, ENNReal.toReal_div]

Result:
case pos
α : Type u_1
β : Type u_2
γ : Type u_3
mα : MeasurableSpace α
mβ : MeasurableSpace β
mγ : MeasurableSpace γ
inst✝ : CountablyGenerated γ
κ : Kernel α (γ × β)
ν : Kernel α γ
κ' : Kernel α (γ × β)
hκκ' : κ ≤ κ'
hκ'ν : κ'.fst ≤ ν
n : ℕ
a : α
x : γ
s : Set β
h0 : (ν a) (countablePartitionSet n x) = 0
⊢ ((κ a) (countablePartitionSet n x ×ˢ s)).toReal / ENNReal.toReal 0 ≤
    ((κ' a) (countablePartitionSet n x ×ˢ s)).toReal / ENNReal.toReal 0

Proof state:
case neg
α : Type u_1
β : Type u_2
γ : Type u_3
mα : MeasurableSpace α
mβ : MeasurableSpace β
mγ : MeasurableSpace γ
inst✝ : CountablyGenerated γ
κ : Kernel α (γ × β)
ν : Kernel α γ
κ' : Kernel α (γ × β)
hκκ' : κ ≤ κ'
hκ'ν : κ'.fst ≤ ν
n : ℕ
a : α
x : γ
s : Set β
h0 : ¬(ν a) (countablePartitionSet n x) = 0
⊢ ((κ a) (countablePartitionSet n x ×ˢ s) / (ν a) (countablePartitionSet n x)).toReal ≤
    ((κ' a) (countablePartitionSet n x ×ˢ s) / (ν a) (countablePartitionSet n x)).toReal

Tactic:
have h_le : κ' a (countablePartitionSet n x ×ˢ s) ≤ ν a (countablePartitionSet n x) :=
  meas_countablePartitionSet_le_of_fst_le hκ'ν n a x s

Result:
case neg
α : Type u_1
β : Type u_2
γ : Type u_3
mα : MeasurableSpace α
mβ : MeasurableSpace β
mγ : MeasurableSpace γ
inst✝ : CountablyGenerated γ
κ : Kernel α (γ × β)
ν : Kernel α γ
κ' : Kernel α (γ × β)
hκκ' : κ ≤ κ'
hκ'ν : κ'.fst ≤ ν
n : ℕ
a : α
x : γ
s : Set β
h0 : ¬(ν a) (countablePartitionSet n x) = 0
h_le : (κ' a) (countablePartitionSet n x ×ˢ s) ≤ (ν a) (countablePartitionSet n x)
⊢ ((κ a) (countablePartitionSet n x ×ˢ s) / (ν a) (countablePartitionSet n x)).toReal ≤
    ((κ' a) (countablePartitionSet n x ×ˢ s) / (ν a) (countablePartitionSet n x)).toReal

Proof state:
case neg.hb
α : Type u_1
β : Type u_2
γ : Type u_3
mα : MeasurableSpace α
mβ : MeasurableSpace β
mγ : MeasurableSpace γ
inst✝ : CountablyGenerated γ
κ : Kernel α (γ × β)
ν : Kernel α γ
κ' : Kernel α (γ × β)
hκκ' : κ ≤ κ'
hκ'ν : κ'.fst ≤ ν
n : ℕ
a : α
x : γ
s : Set β
h0 : ¬(ν a) (countablePartitionSet n x) = 0
h_le : (κ' a) (countablePartitionSet n x ×ˢ s) ≤ (ν a) (countablePartitionSet n x)
⊢ (κ' a) (countablePartitionSet n x ×ˢ s) = ⊤ → (ν a) (countablePartitionSet n x) = ⊤

Tactic:
exact fun h_top ↦ eq_top_mono h_le h_top

Result:
no goals

Proof state:
case neg.h.h
α : Type u_1
β : Type u_2
γ : Type u_3
mα : MeasurableSpace α
mβ : MeasurableSpace β
mγ : MeasurableSpace γ
inst✝ : CountablyGenerated γ
κ : Kernel α (γ × β)
ν : Kernel α γ
κ' : Kernel α (γ × β)
hκκ' : κ ≤ κ'
hκ'ν : κ'.fst ≤ ν
n : ℕ
a : α
x : γ
s : Set β
h0 : ¬(ν a) (countablePartitionSet n x) = 0
h_le : (κ' a) (countablePartitionSet n x ×ˢ s) ≤ (ν a) (countablePartitionSet n x)
⊢ (κ a) (countablePartitionSet n x ×ˢ s) ≤ (κ' a) (countablePartitionSet n x ×ˢ s)

Tactic:
apply hκκ'

Result:
no goals

Proof state:
α : Type u_1
β : Type u_2
γ : Type u_3
mα : MeasurableSpace α
mβ : MeasurableSpace β
mγ : MeasurableSpace γ
inst✝ : CountablyGenerated γ
κ : Kernel α (γ × β)
ν : Kernel α γ
κ' : Kernel α (γ × β)
hκκ' : κ ≤ κ'
hκ'ν : κ'.fst ≤ ν
n : ℕ
a : α
x : γ
s : Set β
⊢ ((κ a) (countablePartitionSet n x ×ˢ s) / (ν a) (countablePartitionSet n x)).toReal ≤
    ((κ' a) (countablePartitionSet n x ×ˢ s) / (ν a) (countablePartitionSet n x)).toReal

Tactic:
by_cases h0 : ν a (countablePartitionSet n x) = 0

Result:
case pos
α : Type u_1
β : Type u_2
γ : Type u_3
mα : MeasurableSpace α
mβ : MeasurableSpace β
mγ : MeasurableSpace γ
inst✝ : CountablyGenerated γ
κ : Kernel α (γ × β)
ν : Kernel α γ
κ' : Kernel α (γ × β)
hκκ' : κ ≤ κ'
hκ'ν : κ'.fst ≤ ν
n : ℕ
a : α
x : γ
s : Set β
h0 : (ν a) (countablePartitionSet n x) = 0
⊢ ((κ a) (countablePartitionSet n x ×ˢ s) / (ν a) (countablePartitionSet n x)).toReal ≤
    ((κ' a) (countablePartitionSet n x ×ˢ s) / (ν a) (countablePartitionSet n x)).toReal

case neg
α : Type u_1
β : Type u_2
γ : Type u_3
mα : MeasurableSpace α
mβ : MeasurableSpace β
mγ : MeasurableSpace γ
inst✝ : CountablyGenerated γ
κ : Kernel α (γ × β)
ν : Kernel α γ
κ' : Kernel α (γ × β)
hκκ' : κ ≤ κ'
hκ'ν : κ'.fst ≤ ν
n : ℕ
a : α
x : γ
s : Set β
h0 : ¬(ν a) (countablePartitionSet n x) = 0
⊢ ((κ a) (countablePartitionSet n x ×ˢ s) / (ν a) (countablePartitionSet n x)).toReal ≤
    ((κ' a) (countablePartitionSet n x ×ˢ s) / (ν a) (countablePartitionSet n x)).toReal