Theorem axunnd 10606

Description: A version of the Axiom of Union with no distinct variable conditions. Usage of this theorem is discouraged because it depends on ax-13 2401. (Contributed by NM, 2-Jan-2002.) (New usage is discouraged.)

Assertion

Ref	Expression
axunnd	⊢ ∃𝑥∀𝑦(∃𝑥(𝑦 ∈ 𝑥 ∧ 𝑥 ∈ 𝑧) → 𝑦 ∈ 𝑥)

Proof of Theorem axunnd

Dummy variable 𝑤 is distinct from all other variables.

Step	Hyp	Ref	Expression
1		axunndlem1 10605	. . . 4 ⊢ ∃𝑤∀𝑦(∃𝑤(𝑦 ∈ 𝑤 ∧ 𝑤 ∈ 𝑧) → 𝑦 ∈ 𝑤)
2		nfnae 2463	. . . . . 6 ⊢ Ⅎ𝑥 ¬ ∀𝑥 𝑥 = 𝑦
3		nfnae 2463	. . . . . 6 ⊢ Ⅎ𝑥 ¬ ∀𝑥 𝑥 = 𝑧
4	2, 3	nfan 1932	. . . . 5 ⊢ Ⅎ𝑥(¬ ∀𝑥 𝑥 = 𝑦 ∧ ¬ ∀𝑥 𝑥 = 𝑧)
5		nfnae 2463	. . . . . . 7 ⊢ Ⅎ𝑦 ¬ ∀𝑥 𝑥 = 𝑦
6		nfnae 2463	. . . . . . 7 ⊢ Ⅎ𝑦 ¬ ∀𝑥 𝑥 = 𝑧
7	5, 6	nfan 1932	. . . . . 6 ⊢ Ⅎ𝑦(¬ ∀𝑥 𝑥 = 𝑦 ∧ ¬ ∀𝑥 𝑥 = 𝑧)
8		nfv 1947	. . . . . . . 8 ⊢ Ⅎ𝑤(¬ ∀𝑥 𝑥 = 𝑦 ∧ ¬ ∀𝑥 𝑥 = 𝑧)
9		nfcvf 2948	. . . . . . . . . . 11 ⊢ (¬ ∀𝑥 𝑥 = 𝑦 → Ⅎ𝑥𝑦)
10	9	adantr 486	. . . . . . . . . 10 ⊢ ((¬ ∀𝑥 𝑥 = 𝑦 ∧ ¬ ∀𝑥 𝑥 = 𝑧) → Ⅎ𝑥𝑦)
11		nfcvd 2923	. . . . . . . . . 10 ⊢ ((¬ ∀𝑥 𝑥 = 𝑦 ∧ ¬ ∀𝑥 𝑥 = 𝑧) → Ⅎ𝑥𝑤)
12	10, 11	nfeld 2933	. . . . . . . . 9 ⊢ ((¬ ∀𝑥 𝑥 = 𝑦 ∧ ¬ ∀𝑥 𝑥 = 𝑧) → Ⅎ𝑥 𝑦 ∈ 𝑤)
13		nfcvf 2948	. . . . . . . . . . 11 ⊢ (¬ ∀𝑥 𝑥 = 𝑧 → Ⅎ𝑥𝑧)
14	13	adantl 487	. . . . . . . . . 10 ⊢ ((¬ ∀𝑥 𝑥 = 𝑦 ∧ ¬ ∀𝑥 𝑥 = 𝑧) → Ⅎ𝑥𝑧)
15	11, 14	nfeld 2933	. . . . . . . . 9 ⊢ ((¬ ∀𝑥 𝑥 = 𝑦 ∧ ¬ ∀𝑥 𝑥 = 𝑧) → Ⅎ𝑥 𝑤 ∈ 𝑧)
16	12, 15	nfand 1930	. . . . . . . 8 ⊢ ((¬ ∀𝑥 𝑥 = 𝑦 ∧ ¬ ∀𝑥 𝑥 = 𝑧) → Ⅎ𝑥(𝑦 ∈ 𝑤 ∧ 𝑤 ∈ 𝑧))
17	8, 16	nfexd 2359	. . . . . . 7 ⊢ ((¬ ∀𝑥 𝑥 = 𝑦 ∧ ¬ ∀𝑥 𝑥 = 𝑧) → Ⅎ𝑥∃𝑤(𝑦 ∈ 𝑤 ∧ 𝑤 ∈ 𝑧))
18	17, 12	nfimd 1927	. . . . . 6 ⊢ ((¬ ∀𝑥 𝑥 = 𝑦 ∧ ¬ ∀𝑥 𝑥 = 𝑧) → Ⅎ𝑥(∃𝑤(𝑦 ∈ 𝑤 ∧ 𝑤 ∈ 𝑧) → 𝑦 ∈ 𝑤))
19	7, 18	nfald 2358	. . . . 5 ⊢ ((¬ ∀𝑥 𝑥 = 𝑦 ∧ ¬ ∀𝑥 𝑥 = 𝑧) → Ⅎ𝑥∀𝑦(∃𝑤(𝑦 ∈ 𝑤 ∧ 𝑤 ∈ 𝑧) → 𝑦 ∈ 𝑤))
20		nfcvd 2923	. . . . . . . . 9 ⊢ ((¬ ∀𝑥 𝑥 = 𝑦 ∧ ¬ ∀𝑥 𝑥 = 𝑧) → Ⅎ𝑦𝑤)
21		nfcvf2 2949	. . . . . . . . . 10 ⊢ (¬ ∀𝑥 𝑥 = 𝑦 → Ⅎ𝑦𝑥)
22	21	adantr 486	. . . . . . . . 9 ⊢ ((¬ ∀𝑥 𝑥 = 𝑦 ∧ ¬ ∀𝑥 𝑥 = 𝑧) → Ⅎ𝑦𝑥)
23	20, 22	nfeqd 2932	. . . . . . . 8 ⊢ ((¬ ∀𝑥 𝑥 = 𝑦 ∧ ¬ ∀𝑥 𝑥 = 𝑧) → Ⅎ𝑦 𝑤 = 𝑥)
24	7, 23	nfan1 2236	. . . . . . 7 ⊢ Ⅎ𝑦((¬ ∀𝑥 𝑥 = 𝑦 ∧ ¬ ∀𝑥 𝑥 = 𝑧) ∧ 𝑤 = 𝑥)
25		elequ2 2160	. . . . . . . . . . . 12 ⊢ (𝑤 = 𝑥 → (𝑦 ∈ 𝑤 ↔ 𝑦 ∈ 𝑥))
26		elequ1 2152	. . . . . . . . . . . 12 ⊢ (𝑤 = 𝑥 → (𝑤 ∈ 𝑧 ↔ 𝑥 ∈ 𝑧))
27	25, 26	anbi12d 644	. . . . . . . . . . 11 ⊢ (𝑤 = 𝑥 → ((𝑦 ∈ 𝑤 ∧ 𝑤 ∈ 𝑧) ↔ (𝑦 ∈ 𝑥 ∧ 𝑥 ∈ 𝑧)))
28	27	a1i 11	. . . . . . . . . 10 ⊢ ((¬ ∀𝑥 𝑥 = 𝑦 ∧ ¬ ∀𝑥 𝑥 = 𝑧) → (𝑤 = 𝑥 → ((𝑦 ∈ 𝑤 ∧ 𝑤 ∈ 𝑧) ↔ (𝑦 ∈ 𝑥 ∧ 𝑥 ∈ 𝑧))))
29	4, 16, 28	cbvexd 2437	. . . . . . . . 9 ⊢ ((¬ ∀𝑥 𝑥 = 𝑦 ∧ ¬ ∀𝑥 𝑥 = 𝑧) → (∃𝑤(𝑦 ∈ 𝑤 ∧ 𝑤 ∈ 𝑧) ↔ ∃𝑥(𝑦 ∈ 𝑥 ∧ 𝑥 ∈ 𝑧)))
30	29	adantr 486	. . . . . . . 8 ⊢ (((¬ ∀𝑥 𝑥 = 𝑦 ∧ ¬ ∀𝑥 𝑥 = 𝑧) ∧ 𝑤 = 𝑥) → (∃𝑤(𝑦 ∈ 𝑤 ∧ 𝑤 ∈ 𝑧) ↔ ∃𝑥(𝑦 ∈ 𝑥 ∧ 𝑥 ∈ 𝑧)))
31	25	adantl 487	. . . . . . . 8 ⊢ (((¬ ∀𝑥 𝑥 = 𝑦 ∧ ¬ ∀𝑥 𝑥 = 𝑧) ∧ 𝑤 = 𝑥) → (𝑦 ∈ 𝑤 ↔ 𝑦 ∈ 𝑥))
32	30, 31	imbi12d 347	. . . . . . 7 ⊢ (((¬ ∀𝑥 𝑥 = 𝑦 ∧ ¬ ∀𝑥 𝑥 = 𝑧) ∧ 𝑤 = 𝑥) → ((∃𝑤(𝑦 ∈ 𝑤 ∧ 𝑤 ∈ 𝑧) → 𝑦 ∈ 𝑤) ↔ (∃𝑥(𝑦 ∈ 𝑥 ∧ 𝑥 ∈ 𝑧) → 𝑦 ∈ 𝑥)))
33	24, 32	albid 2258	. . . . . 6 ⊢ (((¬ ∀𝑥 𝑥 = 𝑦 ∧ ¬ ∀𝑥 𝑥 = 𝑧) ∧ 𝑤 = 𝑥) → (∀𝑦(∃𝑤(𝑦 ∈ 𝑤 ∧ 𝑤 ∈ 𝑧) → 𝑦 ∈ 𝑤) ↔ ∀𝑦(∃𝑥(𝑦 ∈ 𝑥 ∧ 𝑥 ∈ 𝑧) → 𝑦 ∈ 𝑥)))
34	33	ex 418	. . . . 5 ⊢ ((¬ ∀𝑥 𝑥 = 𝑦 ∧ ¬ ∀𝑥 𝑥 = 𝑧) → (𝑤 = 𝑥 → (∀𝑦(∃𝑤(𝑦 ∈ 𝑤 ∧ 𝑤 ∈ 𝑧) → 𝑦 ∈ 𝑤) ↔ ∀𝑦(∃𝑥(𝑦 ∈ 𝑥 ∧ 𝑥 ∈ 𝑧) → 𝑦 ∈ 𝑥))))
35	4, 19, 34	cbvexd 2437	. . . 4 ⊢ ((¬ ∀𝑥 𝑥 = 𝑦 ∧ ¬ ∀𝑥 𝑥 = 𝑧) → (∃𝑤∀𝑦(∃𝑤(𝑦 ∈ 𝑤 ∧ 𝑤 ∈ 𝑧) → 𝑦 ∈ 𝑤) ↔ ∃𝑥∀𝑦(∃𝑥(𝑦 ∈ 𝑥 ∧ 𝑥 ∈ 𝑧) → 𝑦 ∈ 𝑥)))
36	1, 35	mpbii 236	. . 3 ⊢ ((¬ ∀𝑥 𝑥 = 𝑦 ∧ ¬ ∀𝑥 𝑥 = 𝑧) → ∃𝑥∀𝑦(∃𝑥(𝑦 ∈ 𝑥 ∧ 𝑥 ∈ 𝑧) → 𝑦 ∈ 𝑥))
37	36	ex 418	. 2 ⊢ (¬ ∀𝑥 𝑥 = 𝑦 → (¬ ∀𝑥 𝑥 = 𝑧 → ∃𝑥∀𝑦(∃𝑥(𝑦 ∈ 𝑥 ∧ 𝑥 ∈ 𝑧) → 𝑦 ∈ 𝑥)))
38		nfae 2462	. . . 4 ⊢ Ⅎ𝑦∀𝑥 𝑥 = 𝑦
39		nfae 2462	. . . . . 6 ⊢ Ⅎ𝑥∀𝑥 𝑥 = 𝑦
40		elirrv 9570	. . . . . . . . 9 ⊢ ¬ 𝑦 ∈ 𝑦
41		elequ2 2160	. . . . . . . . 9 ⊢ (𝑥 = 𝑦 → (𝑦 ∈ 𝑥 ↔ 𝑦 ∈ 𝑦))
42	40, 41	mtbiri 330	. . . . . . . 8 ⊢ (𝑥 = 𝑦 → ¬ 𝑦 ∈ 𝑥)
43	42	intnanrd 495	. . . . . . 7 ⊢ (𝑥 = 𝑦 → ¬ (𝑦 ∈ 𝑥 ∧ 𝑥 ∈ 𝑧))
44	43	sps 2221	. . . . . 6 ⊢ (∀𝑥 𝑥 = 𝑦 → ¬ (𝑦 ∈ 𝑥 ∧ 𝑥 ∈ 𝑧))
45	39, 44	nexd 2257	. . . . 5 ⊢ (∀𝑥 𝑥 = 𝑦 → ¬ ∃𝑥(𝑦 ∈ 𝑥 ∧ 𝑥 ∈ 𝑧))
46	45	pm2.21d 122	. . . 4 ⊢ (∀𝑥 𝑥 = 𝑦 → (∃𝑥(𝑦 ∈ 𝑥 ∧ 𝑥 ∈ 𝑧) → 𝑦 ∈ 𝑥))
47	38, 46	alrimi 2249	. . 3 ⊢ (∀𝑥 𝑥 = 𝑦 → ∀𝑦(∃𝑥(𝑦 ∈ 𝑥 ∧ 𝑥 ∈ 𝑧) → 𝑦 ∈ 𝑥))
48	47	19.8ad 2218	. 2 ⊢ (∀𝑥 𝑥 = 𝑦 → ∃𝑥∀𝑦(∃𝑥(𝑦 ∈ 𝑥 ∧ 𝑥 ∈ 𝑧) → 𝑦 ∈ 𝑥))
49		nfae 2462	. . . 4 ⊢ Ⅎ𝑦∀𝑥 𝑥 = 𝑧
50		nfae 2462	. . . . . 6 ⊢ Ⅎ𝑥∀𝑥 𝑥 = 𝑧
51		elirrv 9570	. . . . . . . . 9 ⊢ ¬ 𝑧 ∈ 𝑧
52		elequ1 2152	. . . . . . . . 9 ⊢ (𝑥 = 𝑧 → (𝑥 ∈ 𝑧 ↔ 𝑧 ∈ 𝑧))
53	51, 52	mtbiri 330	. . . . . . . 8 ⊢ (𝑥 = 𝑧 → ¬ 𝑥 ∈ 𝑧)
54	53	intnand 494	. . . . . . 7 ⊢ (𝑥 = 𝑧 → ¬ (𝑦 ∈ 𝑥 ∧ 𝑥 ∈ 𝑧))
55	54	sps 2221	. . . . . 6 ⊢ (∀𝑥 𝑥 = 𝑧 → ¬ (𝑦 ∈ 𝑥 ∧ 𝑥 ∈ 𝑧))
56	50, 55	nexd 2257	. . . . 5 ⊢ (∀𝑥 𝑥 = 𝑧 → ¬ ∃𝑥(𝑦 ∈ 𝑥 ∧ 𝑥 ∈ 𝑧))
57	56	pm2.21d 122	. . . 4 ⊢ (∀𝑥 𝑥 = 𝑧 → (∃𝑥(𝑦 ∈ 𝑥 ∧ 𝑥 ∈ 𝑧) → 𝑦 ∈ 𝑥))
58	49, 57	alrimi 2249	. . 3 ⊢ (∀𝑥 𝑥 = 𝑧 → ∀𝑦(∃𝑥(𝑦 ∈ 𝑥 ∧ 𝑥 ∈ 𝑧) → 𝑦 ∈ 𝑥))
59	58	19.8ad 2218	. 2 ⊢ (∀𝑥 𝑥 = 𝑧 → ∃𝑥∀𝑦(∃𝑥(𝑦 ∈ 𝑥 ∧ 𝑥 ∈ 𝑧) → 𝑦 ∈ 𝑥))
60	37, 48, 59	pm2.61ii 185	1 ⊢ ∃𝑥∀𝑦(∃𝑥(𝑦 ∈ 𝑥 ∧ 𝑥 ∈ 𝑧) → 𝑦 ∈ 𝑥)

This proof depends on syntax axioms:  ¬ wn 3   → wi 4   ↔ wb 209   ∧ wa 401  ∀wal 1568  ∃wex 1812  Ⅎwnfc 2907

This proof depends on axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1828  ax-4 1842  ax-5 1943  ax-6 2000  ax-7 2041  ax-8 2147  ax-9 2155  ax-10 2178  ax-11 2194  ax-12 2213  ax-13 2401  ax-ext 2732  ax-sep 5251  ax-pr 5398  ax-un 7737  ax-reg 9565

This proof depends on definitions:  df-bi 210  df-an 402  df-or 862  df-3an 1105  df-tru 1573  df-fal 1583  df-ex 1813  df-nf 1817  df-sb 2100  df-clab 2739  df-cleq 2752  df-clel 2835  df-nfc 2909  df-ne 2956  df-ral 3077  df-rex 3087  df-rab 3413  df-v 3452  df-dif 3902  df-un 3904  df-in 3906  df-ss 3916  df-nul 4280  df-if 4483  df-pw 4559  df-sn 4585  df-pr 4587  df-op 4591  df-br 5104  df-opab 5168  df-eprel 5555  df-fr 5608

This theorem is used by:  zfcndun  10625  axunprim  36283