Theorem iunopeqop 5465

Description: Implication of an ordered pair being equal to an indexed union of singletons of ordered pairs. (Contributed by AV, 20-Sep-2020.) Remove antecedent. (Revised by Eric Schmidt, 9-May-2026.) (Avoid depending on this detail.)

Hypotheses

Ref	Expression
iunopeqop.b	⊢ 𝐵 ∈ V
iunopeqop.c	⊢ 𝐶 ∈ V
iunopeqop.d	⊢ 𝐷 ∈ V

Assertion

Ref	Expression
iunopeqop	⊢ (∪ 𝑥 ∈ 𝐴 {⟨𝑥, 𝐵⟩} = ⟨𝐶, 𝐷⟩ → ∃𝑧 𝐴 = {𝑧})

Distinct variable groups:   𝑥,𝐴,𝑧   𝑥,𝐶   𝑥,𝐷

Allowed substitution hints:   𝐵(𝑥,𝑧)   𝐶(𝑧)   𝐷(𝑧)

Proof of Theorem iunopeqop

Dummy variable 𝑦 is distinct from all other variables.

Step	Hyp	Ref	Expression
1		iunopeqop.c	. . . . . . 7 ⊢ 𝐶 ∈ V
2		iunopeqop.d	. . . . . . 7 ⊢ 𝐷 ∈ V
3	1, 2	opnzi 5417	. . . . . 6 ⊢ ⟨𝐶, 𝐷⟩ ≠ ∅
4	3	a1i 11	. . . . 5 ⊢ (𝐴 = ∅ → ⟨𝐶, 𝐷⟩ ≠ ∅)
5		iuneq1 4941	. . . . . 6 ⊢ (𝐴 = ∅ → ∪ 𝑥 ∈ 𝐴 {⟨𝑥, 𝐵⟩} = ∪ 𝑥 ∈ ∅ {⟨𝑥, 𝐵⟩})
6		0iun 4995	. . . . . 6 ⊢ ∪ 𝑥 ∈ ∅ {⟨𝑥, 𝐵⟩} = ∅
7	5, 6	eqtrdi 2792	. . . . 5 ⊢ (𝐴 = ∅ → ∪ 𝑥 ∈ 𝐴 {⟨𝑥, 𝐵⟩} = ∅)
8	4, 7	neeqtrrd 3010	. . . 4 ⊢ (𝐴 = ∅ → ⟨𝐶, 𝐷⟩ ≠ ∪ 𝑥 ∈ 𝐴 {⟨𝑥, 𝐵⟩})
9		nesym 2992	. . . 4 ⊢ (⟨𝐶, 𝐷⟩ ≠ ∪ 𝑥 ∈ 𝐴 {⟨𝑥, 𝐵⟩} ↔ ¬ ∪ 𝑥 ∈ 𝐴 {⟨𝑥, 𝐵⟩} = ⟨𝐶, 𝐷⟩)
10	8, 9	sylib 220	. . 3 ⊢ (𝐴 = ∅ → ¬ ∪ 𝑥 ∈ 𝐴 {⟨𝑥, 𝐵⟩} = ⟨𝐶, 𝐷⟩)
11	10	pm2.21d 121	. 2 ⊢ (𝐴 = ∅ → (∪ 𝑥 ∈ 𝐴 {⟨𝑥, 𝐵⟩} = ⟨𝐶, 𝐷⟩ → ∃𝑧 𝐴 = {𝑧}))
12		n0snor2el 4767	. . 3 ⊢ (𝐴 ≠ ∅ → (∃𝑥 ∈ 𝐴 ∃𝑦 ∈ 𝐴 𝑥 ≠ 𝑦 ∨ ∃𝑧 𝐴 = {𝑧}))
13		nfiu1 4960	. . . . . . 7 ⊢ Ⅎ𝑥∪ 𝑥 ∈ 𝐴 {⟨𝑥, 𝐵⟩}
14	13	nfeq1 2918	. . . . . 6 ⊢ Ⅎ𝑥∪ 𝑥 ∈ 𝐴 {⟨𝑥, 𝐵⟩} = ⟨𝐶, 𝐷⟩
15		nfv 1922	. . . . . 6 ⊢ Ⅎ𝑥∃𝑧 𝐴 = {𝑧}
16	14, 15	nfim 1904	. . . . 5 ⊢ Ⅎ𝑥(∪ 𝑥 ∈ 𝐴 {⟨𝑥, 𝐵⟩} = ⟨𝐶, 𝐷⟩ → ∃𝑧 𝐴 = {𝑧})
17		ssiun2 4980	. . . . . . . 8 ⊢ (𝑥 ∈ 𝐴 → {⟨𝑥, 𝐵⟩} ⊆ ∪ 𝑥 ∈ 𝐴 {⟨𝑥, 𝐵⟩})
18		nfcv 2903	. . . . . . . . 9 ⊢ Ⅎ𝑥𝑦
19		nfcsb1v 3857	. . . . . . . . . . . 12 ⊢ Ⅎ𝑥⦋𝑦 / 𝑥⦌𝐵
20	18, 19	nfop 4823	. . . . . . . . . . 11 ⊢ Ⅎ𝑥⟨𝑦, ⦋𝑦 / 𝑥⦌𝐵⟩
21	20	nfsn 4642	. . . . . . . . . 10 ⊢ Ⅎ𝑥{⟨𝑦, ⦋𝑦 / 𝑥⦌𝐵⟩}
22	21, 13	nfss 3910	. . . . . . . . 9 ⊢ Ⅎ𝑥{⟨𝑦, ⦋𝑦 / 𝑥⦌𝐵⟩} ⊆ ∪ 𝑥 ∈ 𝐴 {⟨𝑥, 𝐵⟩}
23		id 22	. . . . . . . . . . . 12 ⊢ (𝑥 = 𝑦 → 𝑥 = 𝑦)
24		csbeq1a 3847	. . . . . . . . . . . 12 ⊢ (𝑥 = 𝑦 → 𝐵 = ⦋𝑦 / 𝑥⦌𝐵)
25	23, 24	opeq12d 4815	. . . . . . . . . . 11 ⊢ (𝑥 = 𝑦 → ⟨𝑥, 𝐵⟩ = ⟨𝑦, ⦋𝑦 / 𝑥⦌𝐵⟩)
26	25	sneqd 4570	. . . . . . . . . 10 ⊢ (𝑥 = 𝑦 → {⟨𝑥, 𝐵⟩} = {⟨𝑦, ⦋𝑦 / 𝑥⦌𝐵⟩})
27	26	sseq1d 3948	. . . . . . . . 9 ⊢ (𝑥 = 𝑦 → ({⟨𝑥, 𝐵⟩} ⊆ ∪ 𝑥 ∈ 𝐴 {⟨𝑥, 𝐵⟩} ↔ {⟨𝑦, ⦋𝑦 / 𝑥⦌𝐵⟩} ⊆ ∪ 𝑥 ∈ 𝐴 {⟨𝑥, 𝐵⟩}))
28	18, 22, 27, 17	vtoclgaf 3521	. . . . . . . 8 ⊢ (𝑦 ∈ 𝐴 → {⟨𝑦, ⦋𝑦 / 𝑥⦌𝐵⟩} ⊆ ∪ 𝑥 ∈ 𝐴 {⟨𝑥, 𝐵⟩})
29	17, 28	anim12i 620	. . . . . . 7 ⊢ ((𝑥 ∈ 𝐴 ∧ 𝑦 ∈ 𝐴) → ({⟨𝑥, 𝐵⟩} ⊆ ∪ 𝑥 ∈ 𝐴 {⟨𝑥, 𝐵⟩} ∧ {⟨𝑦, ⦋𝑦 / 𝑥⦌𝐵⟩} ⊆ ∪ 𝑥 ∈ 𝐴 {⟨𝑥, 𝐵⟩}))
30		unss 4122	. . . . . . . 8 ⊢ (({⟨𝑥, 𝐵⟩} ⊆ ∪ 𝑥 ∈ 𝐴 {⟨𝑥, 𝐵⟩} ∧ {⟨𝑦, ⦋𝑦 / 𝑥⦌𝐵⟩} ⊆ ∪ 𝑥 ∈ 𝐴 {⟨𝑥, 𝐵⟩}) ↔ ({⟨𝑥, 𝐵⟩} ∪ {⟨𝑦, ⦋𝑦 / 𝑥⦌𝐵⟩}) ⊆ ∪ 𝑥 ∈ 𝐴 {⟨𝑥, 𝐵⟩})
31		sseq2 3943	. . . . . . . . . 10 ⊢ (∪ 𝑥 ∈ 𝐴 {⟨𝑥, 𝐵⟩} = ⟨𝐶, 𝐷⟩ → (({⟨𝑥, 𝐵⟩} ∪ {⟨𝑦, ⦋𝑦 / 𝑥⦌𝐵⟩}) ⊆ ∪ 𝑥 ∈ 𝐴 {⟨𝑥, 𝐵⟩} ↔ ({⟨𝑥, 𝐵⟩} ∪ {⟨𝑦, ⦋𝑦 / 𝑥⦌𝐵⟩}) ⊆ ⟨𝐶, 𝐷⟩))
32		df-pr 4561	. . . . . . . . . . . . 13 ⊢ {⟨𝑥, 𝐵⟩, ⟨𝑦, ⦋𝑦 / 𝑥⦌𝐵⟩} = ({⟨𝑥, 𝐵⟩} ∪ {⟨𝑦, ⦋𝑦 / 𝑥⦌𝐵⟩})
33	32	eqcomi 2750	. . . . . . . . . . . 12 ⊢ ({⟨𝑥, 𝐵⟩} ∪ {⟨𝑦, ⦋𝑦 / 𝑥⦌𝐵⟩}) = {⟨𝑥, 𝐵⟩, ⟨𝑦, ⦋𝑦 / 𝑥⦌𝐵⟩}
34	33	sseq1i 3945	. . . . . . . . . . 11 ⊢ (({⟨𝑥, 𝐵⟩} ∪ {⟨𝑦, ⦋𝑦 / 𝑥⦌𝐵⟩}) ⊆ ⟨𝐶, 𝐷⟩ ↔ {⟨𝑥, 𝐵⟩, ⟨𝑦, ⦋𝑦 / 𝑥⦌𝐵⟩} ⊆ ⟨𝐶, 𝐷⟩)
35		vex 3437	. . . . . . . . . . . . 13 ⊢ 𝑥 ∈ V
36		iunopeqop.b	. . . . . . . . . . . . 13 ⊢ 𝐵 ∈ V
37		vex 3437	. . . . . . . . . . . . 13 ⊢ 𝑦 ∈ V
38	36	csbex 5236	. . . . . . . . . . . . 13 ⊢ ⦋𝑦 / 𝑥⦌𝐵 ∈ V
39	35, 36, 37, 38, 1, 2	propssopi 5452	. . . . . . . . . . . 12 ⊢ ({⟨𝑥, 𝐵⟩, ⟨𝑦, ⦋𝑦 / 𝑥⦌𝐵⟩} ⊆ ⟨𝐶, 𝐷⟩ → 𝑥 = 𝑦)
40		eqneqall 2947	. . . . . . . . . . . 12 ⊢ (𝑥 = 𝑦 → (𝑥 ≠ 𝑦 → ((𝑥 ∈ 𝐴 ∧ 𝑦 ∈ 𝐴) → ∃𝑧 𝐴 = {𝑧})))
41	39, 40	syl 17	. . . . . . . . . . 11 ⊢ ({⟨𝑥, 𝐵⟩, ⟨𝑦, ⦋𝑦 / 𝑥⦌𝐵⟩} ⊆ ⟨𝐶, 𝐷⟩ → (𝑥 ≠ 𝑦 → ((𝑥 ∈ 𝐴 ∧ 𝑦 ∈ 𝐴) → ∃𝑧 𝐴 = {𝑧})))
42	34, 41	sylbi 219	. . . . . . . . . 10 ⊢ (({⟨𝑥, 𝐵⟩} ∪ {⟨𝑦, ⦋𝑦 / 𝑥⦌𝐵⟩}) ⊆ ⟨𝐶, 𝐷⟩ → (𝑥 ≠ 𝑦 → ((𝑥 ∈ 𝐴 ∧ 𝑦 ∈ 𝐴) → ∃𝑧 𝐴 = {𝑧})))
43	31, 42	biimtrdi 255	. . . . . . . . 9 ⊢ (∪ 𝑥 ∈ 𝐴 {⟨𝑥, 𝐵⟩} = ⟨𝐶, 𝐷⟩ → (({⟨𝑥, 𝐵⟩} ∪ {⟨𝑦, ⦋𝑦 / 𝑥⦌𝐵⟩}) ⊆ ∪ 𝑥 ∈ 𝐴 {⟨𝑥, 𝐵⟩} → (𝑥 ≠ 𝑦 → ((𝑥 ∈ 𝐴 ∧ 𝑦 ∈ 𝐴) → ∃𝑧 𝐴 = {𝑧}))))
44	43	com14 96	. . . . . . . 8 ⊢ ((𝑥 ∈ 𝐴 ∧ 𝑦 ∈ 𝐴) → (({⟨𝑥, 𝐵⟩} ∪ {⟨𝑦, ⦋𝑦 / 𝑥⦌𝐵⟩}) ⊆ ∪ 𝑥 ∈ 𝐴 {⟨𝑥, 𝐵⟩} → (𝑥 ≠ 𝑦 → (∪ 𝑥 ∈ 𝐴 {⟨𝑥, 𝐵⟩} = ⟨𝐶, 𝐷⟩ → ∃𝑧 𝐴 = {𝑧}))))
45	30, 44	biimtrid 244	. . . . . . 7 ⊢ ((𝑥 ∈ 𝐴 ∧ 𝑦 ∈ 𝐴) → (({⟨𝑥, 𝐵⟩} ⊆ ∪ 𝑥 ∈ 𝐴 {⟨𝑥, 𝐵⟩} ∧ {⟨𝑦, ⦋𝑦 / 𝑥⦌𝐵⟩} ⊆ ∪ 𝑥 ∈ 𝐴 {⟨𝑥, 𝐵⟩}) → (𝑥 ≠ 𝑦 → (∪ 𝑥 ∈ 𝐴 {⟨𝑥, 𝐵⟩} = ⟨𝐶, 𝐷⟩ → ∃𝑧 𝐴 = {𝑧}))))
46	29, 45	mpd 15	. . . . . 6 ⊢ ((𝑥 ∈ 𝐴 ∧ 𝑦 ∈ 𝐴) → (𝑥 ≠ 𝑦 → (∪ 𝑥 ∈ 𝐴 {⟨𝑥, 𝐵⟩} = ⟨𝐶, 𝐷⟩ → ∃𝑧 𝐴 = {𝑧})))
47	46	rexlimdva 3142	. . . . 5 ⊢ (𝑥 ∈ 𝐴 → (∃𝑦 ∈ 𝐴 𝑥 ≠ 𝑦 → (∪ 𝑥 ∈ 𝐴 {⟨𝑥, 𝐵⟩} = ⟨𝐶, 𝐷⟩ → ∃𝑧 𝐴 = {𝑧})))
48	16, 47	rexlimi 3241	. . . 4 ⊢ (∃𝑥 ∈ 𝐴 ∃𝑦 ∈ 𝐴 𝑥 ≠ 𝑦 → (∪ 𝑥 ∈ 𝐴 {⟨𝑥, 𝐵⟩} = ⟨𝐶, 𝐷⟩ → ∃𝑧 𝐴 = {𝑧}))
49		ax-1 6	. . . 4 ⊢ (∃𝑧 𝐴 = {𝑧} → (∪ 𝑥 ∈ 𝐴 {⟨𝑥, 𝐵⟩} = ⟨𝐶, 𝐷⟩ → ∃𝑧 𝐴 = {𝑧}))
50	48, 49	jaoi 864	. . 3 ⊢ ((∃𝑥 ∈ 𝐴 ∃𝑦 ∈ 𝐴 𝑥 ≠ 𝑦 ∨ ∃𝑧 𝐴 = {𝑧}) → (∪ 𝑥 ∈ 𝐴 {⟨𝑥, 𝐵⟩} = ⟨𝐶, 𝐷⟩ → ∃𝑧 𝐴 = {𝑧}))
51	12, 50	syl 17	. 2 ⊢ (𝐴 ≠ ∅ → (∪ 𝑥 ∈ 𝐴 {⟨𝑥, 𝐵⟩} = ⟨𝐶, 𝐷⟩ → ∃𝑧 𝐴 = {𝑧}))
52	11, 51	pm2.61ine 3019	1 ⊢ (∪ 𝑥 ∈ 𝐴 {⟨𝑥, 𝐵⟩} = ⟨𝐶, 𝐷⟩ → ∃𝑧 𝐴 = {𝑧})

Syntax hints:  ¬ wn 3   → wi 4   ∧ wa 397   ∨ wo 854   = wceq 1548  ∃wex 1787   ∈ wcel 2121   ≠ wne 2936  ∃wrex 3065  Vcvv 3433  ⦋csb 3833   ∪ cun 3883   ⊆ wss 3885  ∅c0 4264  {csn 4558  {cpr 4560  ⟨cop 4564  ∪ ciun 4924

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1803  ax-4 1817  ax-5 1918  ax-6 1975  ax-7 2016  ax-8 2123  ax-9 2131  ax-10 2154  ax-11 2170  ax-12 2191  ax-ext 2713  ax-sep 5221  ax-nul 5231  ax-pr 5365

This theorem depends on definitions:  df-bi 209  df-an 398  df-or 855  df-3an 1095  df-tru 1551  df-fal 1561  df-ex 1788  df-nf 1792  df-sb 2075  df-clab 2720  df-cleq 2733  df-clel 2816  df-nfc 2890  df-ne 2937  df-ral 3056  df-rex 3066  df-rab 3394  df-v 3435  df-sbc 3726  df-csb 3834  df-dif 3888  df-un 3890  df-in 3892  df-ss 3902  df-nul 4265  df-if 4458  df-sn 4559  df-pr 4561  df-op 4565  df-iun 4926

This theorem is referenced by:  funopsn  7094