Theorem fnessref 36655

Description: A cover is finer iff it has a subcover which is both finer and a refinement. (Contributed by Jeff Hankins, 18-Jan-2010.) (Revised by Thierry Arnoux, 3-Feb-2020.)

Hypotheses

Ref	Expression
fnessref.1	⊢ 𝑋 = ∪ 𝐴
fnessref.2	⊢ 𝑌 = ∪ 𝐵

Assertion

Ref	Expression
fnessref	⊢ (𝑋 = 𝑌 → (𝐴Fne𝐵 ↔ ∃𝑐(𝑐 ⊆ 𝐵 ∧ (𝐴Fne𝑐 ∧ 𝑐Ref𝐴))))

Distinct variable groups:   𝐴,𝑐   𝐵,𝑐   𝑋,𝑐   𝑌,𝑐

Proof of Theorem fnessref

Dummy variables 𝑡 𝑤 𝑥 𝑦 𝑧 are mutually distinct and distinct from all other variables.

Step	Hyp	Ref	Expression
1		fnerel 36636	. . . . . . 7 ⊢ Rel Fne
2	1	brrelex2i 5693	. . . . . 6 ⊢ (𝐴Fne𝐵 → 𝐵 ∈ V)
3	2	adantl 484	. . . . 5 ⊢ ((𝑋 = 𝑌 ∧ 𝐴Fne𝐵) → 𝐵 ∈ V)
4		rabexg 5283	. . . . 5 ⊢ (𝐵 ∈ V → {𝑥 ∈ 𝐵 ∣ ∃𝑦 ∈ 𝐴 𝑥 ⊆ 𝑦} ∈ V)
5	3, 4	syl 17	. . . 4 ⊢ ((𝑋 = 𝑌 ∧ 𝐴Fne𝐵) → {𝑥 ∈ 𝐵 ∣ ∃𝑦 ∈ 𝐴 𝑥 ⊆ 𝑦} ∈ V)
6		ssrab2 4024	. . . . . 6 ⊢ {𝑥 ∈ 𝐵 ∣ ∃𝑦 ∈ 𝐴 𝑥 ⊆ 𝑦} ⊆ 𝐵
7	6	a1i 11	. . . . 5 ⊢ ((𝑋 = 𝑌 ∧ 𝐴Fne𝐵) → {𝑥 ∈ 𝐵 ∣ ∃𝑦 ∈ 𝐴 𝑥 ⊆ 𝑦} ⊆ 𝐵)
8		fnessref.1	. . . . . . . . . . . 12 ⊢ 𝑋 = ∪ 𝐴
9	8	eleq2i 2844	. . . . . . . . . . 11 ⊢ (𝑡 ∈ 𝑋 ↔ 𝑡 ∈ ∪ 𝐴)
10		eluni 4858	. . . . . . . . . . 11 ⊢ (𝑡 ∈ ∪ 𝐴 ↔ ∃𝑧(𝑡 ∈ 𝑧 ∧ 𝑧 ∈ 𝐴))
11	9, 10	bitri 277	. . . . . . . . . 10 ⊢ (𝑡 ∈ 𝑋 ↔ ∃𝑧(𝑡 ∈ 𝑧 ∧ 𝑧 ∈ 𝐴))
12		fnessex 36644	. . . . . . . . . . . . . . . . 17 ⊢ ((𝐴Fne𝐵 ∧ 𝑧 ∈ 𝐴 ∧ 𝑡 ∈ 𝑧) → ∃𝑥 ∈ 𝐵 (𝑡 ∈ 𝑥 ∧ 𝑥 ⊆ 𝑧))
13	12	3expia 1130	. . . . . . . . . . . . . . . 16 ⊢ ((𝐴Fne𝐵 ∧ 𝑧 ∈ 𝐴) → (𝑡 ∈ 𝑧 → ∃𝑥 ∈ 𝐵 (𝑡 ∈ 𝑥 ∧ 𝑥 ⊆ 𝑧)))
14	13	adantll 722	. . . . . . . . . . . . . . 15 ⊢ (((𝑋 = 𝑌 ∧ 𝐴Fne𝐵) ∧ 𝑧 ∈ 𝐴) → (𝑡 ∈ 𝑧 → ∃𝑥 ∈ 𝐵 (𝑡 ∈ 𝑥 ∧ 𝑥 ⊆ 𝑧)))
15		sseq2 3953	. . . . . . . . . . . . . . . . . . . 20 ⊢ (𝑦 = 𝑧 → (𝑥 ⊆ 𝑦 ↔ 𝑥 ⊆ 𝑧))
16	15	rspcev 3572	. . . . . . . . . . . . . . . . . . 19 ⊢ ((𝑧 ∈ 𝐴 ∧ 𝑥 ⊆ 𝑧) → ∃𝑦 ∈ 𝐴 𝑥 ⊆ 𝑦)
17	16	ex 415	. . . . . . . . . . . . . . . . . 18 ⊢ (𝑧 ∈ 𝐴 → (𝑥 ⊆ 𝑧 → ∃𝑦 ∈ 𝐴 𝑥 ⊆ 𝑦))
18	17	adantl 484	. . . . . . . . . . . . . . . . 17 ⊢ (((𝑋 = 𝑌 ∧ 𝐴Fne𝐵) ∧ 𝑧 ∈ 𝐴) → (𝑥 ⊆ 𝑧 → ∃𝑦 ∈ 𝐴 𝑥 ⊆ 𝑦))
19	18	anim2d 620	. . . . . . . . . . . . . . . 16 ⊢ (((𝑋 = 𝑌 ∧ 𝐴Fne𝐵) ∧ 𝑧 ∈ 𝐴) → ((𝑡 ∈ 𝑥 ∧ 𝑥 ⊆ 𝑧) → (𝑡 ∈ 𝑥 ∧ ∃𝑦 ∈ 𝐴 𝑥 ⊆ 𝑦)))
20	19	reximdv 3167	. . . . . . . . . . . . . . 15 ⊢ (((𝑋 = 𝑌 ∧ 𝐴Fne𝐵) ∧ 𝑧 ∈ 𝐴) → (∃𝑥 ∈ 𝐵 (𝑡 ∈ 𝑥 ∧ 𝑥 ⊆ 𝑧) → ∃𝑥 ∈ 𝐵 (𝑡 ∈ 𝑥 ∧ ∃𝑦 ∈ 𝐴 𝑥 ⊆ 𝑦)))
21	14, 20	syld 47	. . . . . . . . . . . . . 14 ⊢ (((𝑋 = 𝑌 ∧ 𝐴Fne𝐵) ∧ 𝑧 ∈ 𝐴) → (𝑡 ∈ 𝑧 → ∃𝑥 ∈ 𝐵 (𝑡 ∈ 𝑥 ∧ ∃𝑦 ∈ 𝐴 𝑥 ⊆ 𝑦)))
22	21	ex 415	. . . . . . . . . . . . 13 ⊢ ((𝑋 = 𝑌 ∧ 𝐴Fne𝐵) → (𝑧 ∈ 𝐴 → (𝑡 ∈ 𝑧 → ∃𝑥 ∈ 𝐵 (𝑡 ∈ 𝑥 ∧ ∃𝑦 ∈ 𝐴 𝑥 ⊆ 𝑦))))
23	22	com23 86	. . . . . . . . . . . 12 ⊢ ((𝑋 = 𝑌 ∧ 𝐴Fne𝐵) → (𝑡 ∈ 𝑧 → (𝑧 ∈ 𝐴 → ∃𝑥 ∈ 𝐵 (𝑡 ∈ 𝑥 ∧ ∃𝑦 ∈ 𝐴 𝑥 ⊆ 𝑦))))
24	23	impd 413	. . . . . . . . . . 11 ⊢ ((𝑋 = 𝑌 ∧ 𝐴Fne𝐵) → ((𝑡 ∈ 𝑧 ∧ 𝑧 ∈ 𝐴) → ∃𝑥 ∈ 𝐵 (𝑡 ∈ 𝑥 ∧ ∃𝑦 ∈ 𝐴 𝑥 ⊆ 𝑦)))
25	24	exlimdv 1943	. . . . . . . . . 10 ⊢ ((𝑋 = 𝑌 ∧ 𝐴Fne𝐵) → (∃𝑧(𝑡 ∈ 𝑧 ∧ 𝑧 ∈ 𝐴) → ∃𝑥 ∈ 𝐵 (𝑡 ∈ 𝑥 ∧ ∃𝑦 ∈ 𝐴 𝑥 ⊆ 𝑦)))
26	11, 25	biimtrid 244	. . . . . . . . 9 ⊢ ((𝑋 = 𝑌 ∧ 𝐴Fne𝐵) → (𝑡 ∈ 𝑋 → ∃𝑥 ∈ 𝐵 (𝑡 ∈ 𝑥 ∧ ∃𝑦 ∈ 𝐴 𝑥 ⊆ 𝑦)))
27		elunirab 4870	. . . . . . . . 9 ⊢ (𝑡 ∈ ∪ {𝑥 ∈ 𝐵 ∣ ∃𝑦 ∈ 𝐴 𝑥 ⊆ 𝑦} ↔ ∃𝑥 ∈ 𝐵 (𝑡 ∈ 𝑥 ∧ ∃𝑦 ∈ 𝐴 𝑥 ⊆ 𝑦))
28	26, 27	imbitrrdi 254	. . . . . . . 8 ⊢ ((𝑋 = 𝑌 ∧ 𝐴Fne𝐵) → (𝑡 ∈ 𝑋 → 𝑡 ∈ ∪ {𝑥 ∈ 𝐵 ∣ ∃𝑦 ∈ 𝐴 𝑥 ⊆ 𝑦}))
29	28	ssrdv 3933	. . . . . . 7 ⊢ ((𝑋 = 𝑌 ∧ 𝐴Fne𝐵) → 𝑋 ⊆ ∪ {𝑥 ∈ 𝐵 ∣ ∃𝑦 ∈ 𝐴 𝑥 ⊆ 𝑦})
30	6	unissi 4864	. . . . . . . 8 ⊢ ∪ {𝑥 ∈ 𝐵 ∣ ∃𝑦 ∈ 𝐴 𝑥 ⊆ 𝑦} ⊆ ∪ 𝐵
31		simpl 485	. . . . . . . . 9 ⊢ ((𝑋 = 𝑌 ∧ 𝐴Fne𝐵) → 𝑋 = 𝑌)
32		fnessref.2	. . . . . . . . 9 ⊢ 𝑌 = ∪ 𝐵
33	31, 32	eqtr2di 2804	. . . . . . . 8 ⊢ ((𝑋 = 𝑌 ∧ 𝐴Fne𝐵) → ∪ 𝐵 = 𝑋)
34	30, 33	sseqtrid 3969	. . . . . . 7 ⊢ ((𝑋 = 𝑌 ∧ 𝐴Fne𝐵) → ∪ {𝑥 ∈ 𝐵 ∣ ∃𝑦 ∈ 𝐴 𝑥 ⊆ 𝑦} ⊆ 𝑋)
35	29, 34	eqssd 3944	. . . . . 6 ⊢ ((𝑋 = 𝑌 ∧ 𝐴Fne𝐵) → 𝑋 = ∪ {𝑥 ∈ 𝐵 ∣ ∃𝑦 ∈ 𝐴 𝑥 ⊆ 𝑦})
36		fnessex 36644	. . . . . . . . . 10 ⊢ ((𝐴Fne𝐵 ∧ 𝑧 ∈ 𝐴 ∧ 𝑡 ∈ 𝑧) → ∃𝑤 ∈ 𝐵 (𝑡 ∈ 𝑤 ∧ 𝑤 ⊆ 𝑧))
37	36	3expb 1129	. . . . . . . . 9 ⊢ ((𝐴Fne𝐵 ∧ (𝑧 ∈ 𝐴 ∧ 𝑡 ∈ 𝑧)) → ∃𝑤 ∈ 𝐵 (𝑡 ∈ 𝑤 ∧ 𝑤 ⊆ 𝑧))
38	37	adantll 722	. . . . . . . 8 ⊢ (((𝑋 = 𝑌 ∧ 𝐴Fne𝐵) ∧ (𝑧 ∈ 𝐴 ∧ 𝑡 ∈ 𝑧)) → ∃𝑤 ∈ 𝐵 (𝑡 ∈ 𝑤 ∧ 𝑤 ⊆ 𝑧))
39		simpl 485	. . . . . . . . . . . . 13 ⊢ ((𝑤 ∈ 𝐵 ∧ (𝑡 ∈ 𝑤 ∧ 𝑤 ⊆ 𝑧)) → 𝑤 ∈ 𝐵)
40	39	a1i 11	. . . . . . . . . . . 12 ⊢ (((𝑋 = 𝑌 ∧ 𝐴Fne𝐵) ∧ (𝑧 ∈ 𝐴 ∧ 𝑡 ∈ 𝑧)) → ((𝑤 ∈ 𝐵 ∧ (𝑡 ∈ 𝑤 ∧ 𝑤 ⊆ 𝑧)) → 𝑤 ∈ 𝐵))
41		sseq2 3953	. . . . . . . . . . . . . . . . 17 ⊢ (𝑦 = 𝑧 → (𝑤 ⊆ 𝑦 ↔ 𝑤 ⊆ 𝑧))
42	41	rspcev 3572	. . . . . . . . . . . . . . . 16 ⊢ ((𝑧 ∈ 𝐴 ∧ 𝑤 ⊆ 𝑧) → ∃𝑦 ∈ 𝐴 𝑤 ⊆ 𝑦)
43	42	expcom 416	. . . . . . . . . . . . . . 15 ⊢ (𝑤 ⊆ 𝑧 → (𝑧 ∈ 𝐴 → ∃𝑦 ∈ 𝐴 𝑤 ⊆ 𝑦))
44	43	ad2antll 737	. . . . . . . . . . . . . 14 ⊢ ((𝑤 ∈ 𝐵 ∧ (𝑡 ∈ 𝑤 ∧ 𝑤 ⊆ 𝑧)) → (𝑧 ∈ 𝐴 → ∃𝑦 ∈ 𝐴 𝑤 ⊆ 𝑦))
45	44	com12 32	. . . . . . . . . . . . 13 ⊢ (𝑧 ∈ 𝐴 → ((𝑤 ∈ 𝐵 ∧ (𝑡 ∈ 𝑤 ∧ 𝑤 ⊆ 𝑧)) → ∃𝑦 ∈ 𝐴 𝑤 ⊆ 𝑦))
46	45	ad2antrl 736	. . . . . . . . . . . 12 ⊢ (((𝑋 = 𝑌 ∧ 𝐴Fne𝐵) ∧ (𝑧 ∈ 𝐴 ∧ 𝑡 ∈ 𝑧)) → ((𝑤 ∈ 𝐵 ∧ (𝑡 ∈ 𝑤 ∧ 𝑤 ⊆ 𝑧)) → ∃𝑦 ∈ 𝐴 𝑤 ⊆ 𝑦))
47	40, 46	jcad 519	. . . . . . . . . . 11 ⊢ (((𝑋 = 𝑌 ∧ 𝐴Fne𝐵) ∧ (𝑧 ∈ 𝐴 ∧ 𝑡 ∈ 𝑧)) → ((𝑤 ∈ 𝐵 ∧ (𝑡 ∈ 𝑤 ∧ 𝑤 ⊆ 𝑧)) → (𝑤 ∈ 𝐵 ∧ ∃𝑦 ∈ 𝐴 𝑤 ⊆ 𝑦)))
48		sseq1 3952	. . . . . . . . . . . . 13 ⊢ (𝑥 = 𝑤 → (𝑥 ⊆ 𝑦 ↔ 𝑤 ⊆ 𝑦))
49	48	rexbidv 3176	. . . . . . . . . . . 12 ⊢ (𝑥 = 𝑤 → (∃𝑦 ∈ 𝐴 𝑥 ⊆ 𝑦 ↔ ∃𝑦 ∈ 𝐴 𝑤 ⊆ 𝑦))
50	49	elrab 3641	. . . . . . . . . . 11 ⊢ (𝑤 ∈ {𝑥 ∈ 𝐵 ∣ ∃𝑦 ∈ 𝐴 𝑥 ⊆ 𝑦} ↔ (𝑤 ∈ 𝐵 ∧ ∃𝑦 ∈ 𝐴 𝑤 ⊆ 𝑦))
51	47, 50	imbitrrdi 254	. . . . . . . . . 10 ⊢ (((𝑋 = 𝑌 ∧ 𝐴Fne𝐵) ∧ (𝑧 ∈ 𝐴 ∧ 𝑡 ∈ 𝑧)) → ((𝑤 ∈ 𝐵 ∧ (𝑡 ∈ 𝑤 ∧ 𝑤 ⊆ 𝑧)) → 𝑤 ∈ {𝑥 ∈ 𝐵 ∣ ∃𝑦 ∈ 𝐴 𝑥 ⊆ 𝑦}))
52		simpr 487	. . . . . . . . . . 11 ⊢ ((𝑤 ∈ 𝐵 ∧ (𝑡 ∈ 𝑤 ∧ 𝑤 ⊆ 𝑧)) → (𝑡 ∈ 𝑤 ∧ 𝑤 ⊆ 𝑧))
53	52	a1i 11	. . . . . . . . . 10 ⊢ (((𝑋 = 𝑌 ∧ 𝐴Fne𝐵) ∧ (𝑧 ∈ 𝐴 ∧ 𝑡 ∈ 𝑧)) → ((𝑤 ∈ 𝐵 ∧ (𝑡 ∈ 𝑤 ∧ 𝑤 ⊆ 𝑧)) → (𝑡 ∈ 𝑤 ∧ 𝑤 ⊆ 𝑧)))
54	51, 53	jcad 519	. . . . . . . . 9 ⊢ (((𝑋 = 𝑌 ∧ 𝐴Fne𝐵) ∧ (𝑧 ∈ 𝐴 ∧ 𝑡 ∈ 𝑧)) → ((𝑤 ∈ 𝐵 ∧ (𝑡 ∈ 𝑤 ∧ 𝑤 ⊆ 𝑧)) → (𝑤 ∈ {𝑥 ∈ 𝐵 ∣ ∃𝑦 ∈ 𝐴 𝑥 ⊆ 𝑦} ∧ (𝑡 ∈ 𝑤 ∧ 𝑤 ⊆ 𝑧))))
55	54	reximdv2 3162	. . . . . . . 8 ⊢ (((𝑋 = 𝑌 ∧ 𝐴Fne𝐵) ∧ (𝑧 ∈ 𝐴 ∧ 𝑡 ∈ 𝑧)) → (∃𝑤 ∈ 𝐵 (𝑡 ∈ 𝑤 ∧ 𝑤 ⊆ 𝑧) → ∃𝑤 ∈ {𝑥 ∈ 𝐵 ∣ ∃𝑦 ∈ 𝐴 𝑥 ⊆ 𝑦} (𝑡 ∈ 𝑤 ∧ 𝑤 ⊆ 𝑧)))
56	38, 55	mpd 15	. . . . . . 7 ⊢ (((𝑋 = 𝑌 ∧ 𝐴Fne𝐵) ∧ (𝑧 ∈ 𝐴 ∧ 𝑡 ∈ 𝑧)) → ∃𝑤 ∈ {𝑥 ∈ 𝐵 ∣ ∃𝑦 ∈ 𝐴 𝑥 ⊆ 𝑦} (𝑡 ∈ 𝑤 ∧ 𝑤 ⊆ 𝑧))
57	56	ralrimivva 3195	. . . . . 6 ⊢ ((𝑋 = 𝑌 ∧ 𝐴Fne𝐵) → ∀𝑧 ∈ 𝐴 ∀𝑡 ∈ 𝑧 ∃𝑤 ∈ {𝑥 ∈ 𝐵 ∣ ∃𝑦 ∈ 𝐴 𝑥 ⊆ 𝑦} (𝑡 ∈ 𝑤 ∧ 𝑤 ⊆ 𝑧))
58		eqid 2752	. . . . . . . 8 ⊢ ∪ {𝑥 ∈ 𝐵 ∣ ∃𝑦 ∈ 𝐴 𝑥 ⊆ 𝑦} = ∪ {𝑥 ∈ 𝐵 ∣ ∃𝑦 ∈ 𝐴 𝑥 ⊆ 𝑦}
59	8, 58	isfne2 36640	. . . . . . 7 ⊢ ({𝑥 ∈ 𝐵 ∣ ∃𝑦 ∈ 𝐴 𝑥 ⊆ 𝑦} ∈ V → (𝐴Fne{𝑥 ∈ 𝐵 ∣ ∃𝑦 ∈ 𝐴 𝑥 ⊆ 𝑦} ↔ (𝑋 = ∪ {𝑥 ∈ 𝐵 ∣ ∃𝑦 ∈ 𝐴 𝑥 ⊆ 𝑦} ∧ ∀𝑧 ∈ 𝐴 ∀𝑡 ∈ 𝑧 ∃𝑤 ∈ {𝑥 ∈ 𝐵 ∣ ∃𝑦 ∈ 𝐴 𝑥 ⊆ 𝑦} (𝑡 ∈ 𝑤 ∧ 𝑤 ⊆ 𝑧))))
60	3, 4, 59	3syl 18	. . . . . 6 ⊢ ((𝑋 = 𝑌 ∧ 𝐴Fne𝐵) → (𝐴Fne{𝑥 ∈ 𝐵 ∣ ∃𝑦 ∈ 𝐴 𝑥 ⊆ 𝑦} ↔ (𝑋 = ∪ {𝑥 ∈ 𝐵 ∣ ∃𝑦 ∈ 𝐴 𝑥 ⊆ 𝑦} ∧ ∀𝑧 ∈ 𝐴 ∀𝑡 ∈ 𝑧 ∃𝑤 ∈ {𝑥 ∈ 𝐵 ∣ ∃𝑦 ∈ 𝐴 𝑥 ⊆ 𝑦} (𝑡 ∈ 𝑤 ∧ 𝑤 ⊆ 𝑧))))
61	35, 57, 60	mpbir2and 721	. . . . 5 ⊢ ((𝑋 = 𝑌 ∧ 𝐴Fne𝐵) → 𝐴Fne{𝑥 ∈ 𝐵 ∣ ∃𝑦 ∈ 𝐴 𝑥 ⊆ 𝑦})
62		sseq1 3952	. . . . . . . . . 10 ⊢ (𝑥 = 𝑧 → (𝑥 ⊆ 𝑦 ↔ 𝑧 ⊆ 𝑦))
63	62	rexbidv 3176	. . . . . . . . 9 ⊢ (𝑥 = 𝑧 → (∃𝑦 ∈ 𝐴 𝑥 ⊆ 𝑦 ↔ ∃𝑦 ∈ 𝐴 𝑧 ⊆ 𝑦))
64	63	elrab 3641	. . . . . . . 8 ⊢ (𝑧 ∈ {𝑥 ∈ 𝐵 ∣ ∃𝑦 ∈ 𝐴 𝑥 ⊆ 𝑦} ↔ (𝑧 ∈ 𝐵 ∧ ∃𝑦 ∈ 𝐴 𝑧 ⊆ 𝑦))
65		sseq2 3953	. . . . . . . . . . 11 ⊢ (𝑦 = 𝑤 → (𝑧 ⊆ 𝑦 ↔ 𝑧 ⊆ 𝑤))
66	65	cbvrexvw 3231	. . . . . . . . . 10 ⊢ (∃𝑦 ∈ 𝐴 𝑧 ⊆ 𝑦 ↔ ∃𝑤 ∈ 𝐴 𝑧 ⊆ 𝑤)
67	66	bilani 507	. . . . . . . . 9 ⊢ ((𝑧 ∈ 𝐵 ∧ ∃𝑦 ∈ 𝐴 𝑧 ⊆ 𝑦) → ∃𝑤 ∈ 𝐴 𝑧 ⊆ 𝑤)
68	67	a1i 11	. . . . . . . 8 ⊢ ((𝑋 = 𝑌 ∧ 𝐴Fne𝐵) → ((𝑧 ∈ 𝐵 ∧ ∃𝑦 ∈ 𝐴 𝑧 ⊆ 𝑦) → ∃𝑤 ∈ 𝐴 𝑧 ⊆ 𝑤))
69	64, 68	biimtrid 244	. . . . . . 7 ⊢ ((𝑋 = 𝑌 ∧ 𝐴Fne𝐵) → (𝑧 ∈ {𝑥 ∈ 𝐵 ∣ ∃𝑦 ∈ 𝐴 𝑥 ⊆ 𝑦} → ∃𝑤 ∈ 𝐴 𝑧 ⊆ 𝑤))
70	69	ralrimiv 3143	. . . . . 6 ⊢ ((𝑋 = 𝑌 ∧ 𝐴Fne𝐵) → ∀𝑧 ∈ {𝑥 ∈ 𝐵 ∣ ∃𝑦 ∈ 𝐴 𝑥 ⊆ 𝑦}∃𝑤 ∈ 𝐴 𝑧 ⊆ 𝑤)
71	58, 8	isref 23538	. . . . . . 7 ⊢ ({𝑥 ∈ 𝐵 ∣ ∃𝑦 ∈ 𝐴 𝑥 ⊆ 𝑦} ∈ V → ({𝑥 ∈ 𝐵 ∣ ∃𝑦 ∈ 𝐴 𝑥 ⊆ 𝑦}Ref𝐴 ↔ (𝑋 = ∪ {𝑥 ∈ 𝐵 ∣ ∃𝑦 ∈ 𝐴 𝑥 ⊆ 𝑦} ∧ ∀𝑧 ∈ {𝑥 ∈ 𝐵 ∣ ∃𝑦 ∈ 𝐴 𝑥 ⊆ 𝑦}∃𝑤 ∈ 𝐴 𝑧 ⊆ 𝑤)))
72	3, 4, 71	3syl 18	. . . . . 6 ⊢ ((𝑋 = 𝑌 ∧ 𝐴Fne𝐵) → ({𝑥 ∈ 𝐵 ∣ ∃𝑦 ∈ 𝐴 𝑥 ⊆ 𝑦}Ref𝐴 ↔ (𝑋 = ∪ {𝑥 ∈ 𝐵 ∣ ∃𝑦 ∈ 𝐴 𝑥 ⊆ 𝑦} ∧ ∀𝑧 ∈ {𝑥 ∈ 𝐵 ∣ ∃𝑦 ∈ 𝐴 𝑥 ⊆ 𝑦}∃𝑤 ∈ 𝐴 𝑧 ⊆ 𝑤)))
73	35, 70, 72	mpbir2and 721	. . . . 5 ⊢ ((𝑋 = 𝑌 ∧ 𝐴Fne𝐵) → {𝑥 ∈ 𝐵 ∣ ∃𝑦 ∈ 𝐴 𝑥 ⊆ 𝑦}Ref𝐴)
74	7, 61, 73	jca32 522	. . . 4 ⊢ ((𝑋 = 𝑌 ∧ 𝐴Fne𝐵) → ({𝑥 ∈ 𝐵 ∣ ∃𝑦 ∈ 𝐴 𝑥 ⊆ 𝑦} ⊆ 𝐵 ∧ (𝐴Fne{𝑥 ∈ 𝐵 ∣ ∃𝑦 ∈ 𝐴 𝑥 ⊆ 𝑦} ∧ {𝑥 ∈ 𝐵 ∣ ∃𝑦 ∈ 𝐴 𝑥 ⊆ 𝑦}Ref𝐴)))
75		sseq1 3952	. . . . . 6 ⊢ (𝑐 = {𝑥 ∈ 𝐵 ∣ ∃𝑦 ∈ 𝐴 𝑥 ⊆ 𝑦} → (𝑐 ⊆ 𝐵 ↔ {𝑥 ∈ 𝐵 ∣ ∃𝑦 ∈ 𝐴 𝑥 ⊆ 𝑦} ⊆ 𝐵))
76		breq2 5094	. . . . . . 7 ⊢ (𝑐 = {𝑥 ∈ 𝐵 ∣ ∃𝑦 ∈ 𝐴 𝑥 ⊆ 𝑦} → (𝐴Fne𝑐 ↔ 𝐴Fne{𝑥 ∈ 𝐵 ∣ ∃𝑦 ∈ 𝐴 𝑥 ⊆ 𝑦}))
77		breq1 5093	. . . . . . 7 ⊢ (𝑐 = {𝑥 ∈ 𝐵 ∣ ∃𝑦 ∈ 𝐴 𝑥 ⊆ 𝑦} → (𝑐Ref𝐴 ↔ {𝑥 ∈ 𝐵 ∣ ∃𝑦 ∈ 𝐴 𝑥 ⊆ 𝑦}Ref𝐴))
78	76, 77	anbi12d 640	. . . . . 6 ⊢ (𝑐 = {𝑥 ∈ 𝐵 ∣ ∃𝑦 ∈ 𝐴 𝑥 ⊆ 𝑦} → ((𝐴Fne𝑐 ∧ 𝑐Ref𝐴) ↔ (𝐴Fne{𝑥 ∈ 𝐵 ∣ ∃𝑦 ∈ 𝐴 𝑥 ⊆ 𝑦} ∧ {𝑥 ∈ 𝐵 ∣ ∃𝑦 ∈ 𝐴 𝑥 ⊆ 𝑦}Ref𝐴)))
79	75, 78	anbi12d 640	. . . . 5 ⊢ (𝑐 = {𝑥 ∈ 𝐵 ∣ ∃𝑦 ∈ 𝐴 𝑥 ⊆ 𝑦} → ((𝑐 ⊆ 𝐵 ∧ (𝐴Fne𝑐 ∧ 𝑐Ref𝐴)) ↔ ({𝑥 ∈ 𝐵 ∣ ∃𝑦 ∈ 𝐴 𝑥 ⊆ 𝑦} ⊆ 𝐵 ∧ (𝐴Fne{𝑥 ∈ 𝐵 ∣ ∃𝑦 ∈ 𝐴 𝑥 ⊆ 𝑦} ∧ {𝑥 ∈ 𝐵 ∣ ∃𝑦 ∈ 𝐴 𝑥 ⊆ 𝑦}Ref𝐴))))
80	79	spcegv 3547	. . . 4 ⊢ ({𝑥 ∈ 𝐵 ∣ ∃𝑦 ∈ 𝐴 𝑥 ⊆ 𝑦} ∈ V → (({𝑥 ∈ 𝐵 ∣ ∃𝑦 ∈ 𝐴 𝑥 ⊆ 𝑦} ⊆ 𝐵 ∧ (𝐴Fne{𝑥 ∈ 𝐵 ∣ ∃𝑦 ∈ 𝐴 𝑥 ⊆ 𝑦} ∧ {𝑥 ∈ 𝐵 ∣ ∃𝑦 ∈ 𝐴 𝑥 ⊆ 𝑦}Ref𝐴)) → ∃𝑐(𝑐 ⊆ 𝐵 ∧ (𝐴Fne𝑐 ∧ 𝑐Ref𝐴))))
81	5, 74, 80	sylc 65	. . 3 ⊢ ((𝑋 = 𝑌 ∧ 𝐴Fne𝐵) → ∃𝑐(𝑐 ⊆ 𝐵 ∧ (𝐴Fne𝑐 ∧ 𝑐Ref𝐴)))
82	81	ex 415	. 2 ⊢ (𝑋 = 𝑌 → (𝐴Fne𝐵 → ∃𝑐(𝑐 ⊆ 𝐵 ∧ (𝐴Fne𝑐 ∧ 𝑐Ref𝐴))))
83		simprrl 788	. . . . 5 ⊢ ((𝑋 = 𝑌 ∧ (𝑐 ⊆ 𝐵 ∧ (𝐴Fne𝑐 ∧ 𝑐Ref𝐴))) → 𝐴Fne𝑐)
84		eqid 2752	. . . . . . . . . . . 12 ⊢ ∪ 𝑐 = ∪ 𝑐
85	8, 84	fnebas 36642	. . . . . . . . . . 11 ⊢ (𝐴Fne𝑐 → 𝑋 = ∪ 𝑐)
86	83, 85	syl 17	. . . . . . . . . 10 ⊢ ((𝑋 = 𝑌 ∧ (𝑐 ⊆ 𝐵 ∧ (𝐴Fne𝑐 ∧ 𝑐Ref𝐴))) → 𝑋 = ∪ 𝑐)
87		simpl 485	. . . . . . . . . 10 ⊢ ((𝑋 = 𝑌 ∧ (𝑐 ⊆ 𝐵 ∧ (𝐴Fne𝑐 ∧ 𝑐Ref𝐴))) → 𝑋 = 𝑌)
88	86, 87	eqtr3d 2789	. . . . . . . . 9 ⊢ ((𝑋 = 𝑌 ∧ (𝑐 ⊆ 𝐵 ∧ (𝐴Fne𝑐 ∧ 𝑐Ref𝐴))) → ∪ 𝑐 = 𝑌)
89	88, 32	eqtrdi 2803	. . . . . . . 8 ⊢ ((𝑋 = 𝑌 ∧ (𝑐 ⊆ 𝐵 ∧ (𝐴Fne𝑐 ∧ 𝑐Ref𝐴))) → ∪ 𝑐 = ∪ 𝐵)
90		vuniex 7707	. . . . . . . 8 ⊢ ∪ 𝑐 ∈ V
91	89, 90	eqeltrrdi 2861	. . . . . . 7 ⊢ ((𝑋 = 𝑌 ∧ (𝑐 ⊆ 𝐵 ∧ (𝐴Fne𝑐 ∧ 𝑐Ref𝐴))) → ∪ 𝐵 ∈ V)
92		uniexb 7732	. . . . . . 7 ⊢ (𝐵 ∈ V ↔ ∪ 𝐵 ∈ V)
93	91, 92	sylibr 236	. . . . . 6 ⊢ ((𝑋 = 𝑌 ∧ (𝑐 ⊆ 𝐵 ∧ (𝐴Fne𝑐 ∧ 𝑐Ref𝐴))) → 𝐵 ∈ V)
94		simprl 778	. . . . . 6 ⊢ ((𝑋 = 𝑌 ∧ (𝑐 ⊆ 𝐵 ∧ (𝐴Fne𝑐 ∧ 𝑐Ref𝐴))) → 𝑐 ⊆ 𝐵)
95	84, 32	fness 36647	. . . . . 6 ⊢ ((𝐵 ∈ V ∧ 𝑐 ⊆ 𝐵 ∧ ∪ 𝑐 = 𝑌) → 𝑐Fne𝐵)
96	93, 94, 88, 95	syl3anc 1382	. . . . 5 ⊢ ((𝑋 = 𝑌 ∧ (𝑐 ⊆ 𝐵 ∧ (𝐴Fne𝑐 ∧ 𝑐Ref𝐴))) → 𝑐Fne𝐵)
97		fnetr 36649	. . . . 5 ⊢ ((𝐴Fne𝑐 ∧ 𝑐Fne𝐵) → 𝐴Fne𝐵)
98	83, 96, 97	syl2anc 592	. . . 4 ⊢ ((𝑋 = 𝑌 ∧ (𝑐 ⊆ 𝐵 ∧ (𝐴Fne𝑐 ∧ 𝑐Ref𝐴))) → 𝐴Fne𝐵)
99	98	ex 415	. . 3 ⊢ (𝑋 = 𝑌 → ((𝑐 ⊆ 𝐵 ∧ (𝐴Fne𝑐 ∧ 𝑐Ref𝐴)) → 𝐴Fne𝐵))
100	99	exlimdv 1943	. 2 ⊢ (𝑋 = 𝑌 → (∃𝑐(𝑐 ⊆ 𝐵 ∧ (𝐴Fne𝑐 ∧ 𝑐Ref𝐴)) → 𝐴Fne𝐵))
101	82, 100	impbid 214	1 ⊢ (𝑋 = 𝑌 → (𝐴Fne𝐵 ↔ ∃𝑐(𝑐 ⊆ 𝐵 ∧ (𝐴Fne𝑐 ∧ 𝑐Ref𝐴))))

Syntax hints:   → wi 4   ↔ wb 208   ∧ wa 398   = wceq 1550  ∃wex 1789   ∈ wcel 2132  ∀wral 3066  ∃wrex 3076  {crab 3404  Vcvv 3444   ⊆ wss 3895  ∪ cuni 4855   class class class wbr 5090  Refcref 23531  Fnecfne 36634

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1805  ax-4 1819  ax-5 1920  ax-6 1977  ax-7 2018  ax-8 2134  ax-9 2142  ax-10 2165  ax-11 2181  ax-12 2202  ax-ext 2724  ax-sep 5236  ax-nul 5246  ax-pow 5312  ax-pr 5380  ax-un 7703

This theorem depends on definitions:  df-bi 209  df-an 399  df-or 857  df-3an 1097  df-tru 1553  df-fal 1563  df-ex 1790  df-nf 1794  df-sb 2081  df-mo 2556  df-eu 2586  df-clab 2731  df-cleq 2744  df-clel 2827  df-nfc 2901  df-ne 2948  df-ral 3067  df-rex 3077  df-rab 3405  df-v 3446  df-dif 3898  df-un 3900  df-in 3902  df-ss 3912  df-nul 4277  df-if 4471  df-pw 4547  df-sn 4573  df-pr 4575  df-op 4579  df-uni 4856  df-iun 4941  df-br 5091  df-opab 5153  df-mpt 5172  df-id 5531  df-xp 5642  df-rel 5643  df-cnv 5644  df-co 5645  df-dm 5646  df-iota 6462  df-fun 6508  df-fv 6514  df-topgen 17444  df-ref 23534  df-fne 36635

This theorem is referenced by: (None)