have h : ∀ a, a ∈ A r → Prod.fst a ∈ @Finset.univ C _ := by intros; apply Finset.mem_univ
C : Type u_1
J : Type u_2
r : C → J → Prop
inst✝¹ : Fintype J
inst✝ : Fintype C
z : ℕ
hJ : Fintype.card J = 2 * z + 1
⊢ 2 * z * z * Fintype.card C ≤ (A r).card
C : Type u_1
J : Type u_2
r : C → J → Prop
inst✝¹ : Fintype J
inst✝ : Fintype C
z : ℕ
hJ : Fintype.card J = 2 * z + 1
h : ∀ a ∈ A r, a.1 ∈ Finset.univ
⊢ 2 * z * z * Fintype.card C ≤ (A r).card