Definition df-fne 34263

Description: Define the fineness relation for covers. (Contributed by Jeff Hankins, 28-Sep-2009.)

Assertion

Ref	Expression
df-fne	⊢ Fne = {⟨𝑥, 𝑦⟩ ∣ (∪ 𝑥 = ∪ 𝑦 ∧ ∀𝑧 ∈ 𝑥 𝑧 ⊆ ∪ (𝑦 ∩ 𝒫 𝑧))}

Distinct variable group:   𝑥,𝑦,𝑧

Detailed syntax breakdown of Definition df-fne

Step	Hyp	Ref	Expression
1		cfne 34262	. 2 class Fne
2		vx	. . . . . . 7 setvar 𝑥
3	2	cv 1542	. . . . . 6 class 𝑥
4	3	cuni 4819	. . . . 5 class ∪ 𝑥
5		vy	. . . . . . 7 setvar 𝑦
6	5	cv 1542	. . . . . 6 class 𝑦
7	6	cuni 4819	. . . . 5 class ∪ 𝑦
8	4, 7	wceq 1543	. . . 4 wff ∪ 𝑥 = ∪ 𝑦
9		vz	. . . . . . 7 setvar 𝑧
10	9	cv 1542	. . . . . 6 class 𝑧
11	10	cpw 4513	. . . . . . . 8 class 𝒫 𝑧
12	6, 11	cin 3865	. . . . . . 7 class (𝑦 ∩ 𝒫 𝑧)
13	12	cuni 4819	. . . . . 6 class ∪ (𝑦 ∩ 𝒫 𝑧)
14	10, 13	wss 3866	. . . . 5 wff 𝑧 ⊆ ∪ (𝑦 ∩ 𝒫 𝑧)
15	14, 9, 3	wral 3061	. . . 4 wff ∀𝑧 ∈ 𝑥 𝑧 ⊆ ∪ (𝑦 ∩ 𝒫 𝑧)
16	8, 15	wa 399	. . 3 wff (∪ 𝑥 = ∪ 𝑦 ∧ ∀𝑧 ∈ 𝑥 𝑧 ⊆ ∪ (𝑦 ∩ 𝒫 𝑧))
17	16, 2, 5	copab 5115	. 2 class {⟨𝑥, 𝑦⟩ ∣ (∪ 𝑥 = ∪ 𝑦 ∧ ∀𝑧 ∈ 𝑥 𝑧 ⊆ ∪ (𝑦 ∩ 𝒫 𝑧))}
18	1, 17	wceq 1543	1 wff Fne = {⟨𝑥, 𝑦⟩ ∣ (∪ 𝑥 = ∪ 𝑦 ∧ ∀𝑧 ∈ 𝑥 𝑧 ⊆ ∪ (𝑦 ∩ 𝒫 𝑧))}

This definition is referenced by:  fnerel  34264  isfne  34265