α : Type u_1
β : Type ?u.385073
γ : Type ?u.385076
δ : Type ?u.385079
ι : Type ?u.385082
R : Type ?u.385085
R' : Type ?u.385088
m0 : MeasurableSpace α
inst✝² : MeasurableSpace β
inst✝¹ : MeasurableSpace γ
μ μ₁ μ₂ μ₃ ν ν' ν₁ ν₂ : Measure α
s s' t : Set α
inst✝ : MeasurableSpace α
a : α
ha : MeasurableSet {a}
⊢ ↑(Finset.card (toFinset {a})) = 1
α : Type u_1
β : Type ?u.385073
γ : Type ?u.385076
δ : Type ?u.385079
ι : Type ?u.385082
R : Type ?u.385085
R' : Type ?u.385088
m0 : MeasurableSpace α
inst✝² : MeasurableSpace β
inst✝¹ : MeasurableSpace γ
μ μ₁ μ₂ μ₃ ν ν' ν₁ ν₂ : Measure α
s s' t : Set α
inst✝ : MeasurableSpace α
a : α
ha : MeasurableSet {a}
⊢ ↑↑count {a} = 1
rw [count_apply_finite' (Set.finite_singleton a) ha, Set.Finite.toFinset]
no goals
α : Type u_1
β : Type ?u.385073
γ : Type ?u.385076
δ : Type ?u.385079
ι : Type ?u.385082
R : Type ?u.385085
R' : Type ?u.385088
m0 : MeasurableSpace α
inst✝² : MeasurableSpace β
inst✝¹ : MeasurableSpace γ
μ μ₁ μ₂ μ₃ ν ν' ν₁ ν₂ : Measure α
s s' t : Set α
inst✝ : MeasurableSpace α
a : α
ha : MeasurableSet {a}
⊢ ↑(Finset.card (toFinset {a})) = 1
simp [@toFinset_card _ _ (Set.finite_singleton a).fintype,
  @Fintype.card_unique _ _ (Set.finite_singleton a).fintype]