Theorem opthprc 5746

Description: Justification theorem for an ordered pair definition that works for any classes, including proper classes. This is a possible definition implied by the footnote in [Jech] p. 78, which says, "The sophisticated reader will not object to our use of a pair of classes." (Contributed by NM, 28-Sep-2003.)

Assertion

Ref	Expression
opthprc	⊢ (((𝐴 × {∅}) ∪ (𝐵 × {{∅}})) = ((𝐶 × {∅}) ∪ (𝐷 × {{∅}})) ↔ (𝐴 = 𝐶 ∧ 𝐵 = 𝐷))

Proof of Theorem opthprc

Dummy variable 𝑥 is distinct from all other variables.

Step	Hyp	Ref	Expression
1		eleq2 2818	. . . . 5 ⊢ (((𝐴 × {∅}) ∪ (𝐵 × {{∅}})) = ((𝐶 × {∅}) ∪ (𝐷 × {{∅}})) → (⟨𝑥, ∅⟩ ∈ ((𝐴 × {∅}) ∪ (𝐵 × {{∅}})) ↔ ⟨𝑥, ∅⟩ ∈ ((𝐶 × {∅}) ∪ (𝐷 × {{∅}}))))
2		0ex 5311	. . . . . . . . 9 ⊢ ∅ ∈ V
3	2	snid 4669	. . . . . . . 8 ⊢ ∅ ∈ {∅}
4		opelxp 5718	. . . . . . . 8 ⊢ (⟨𝑥, ∅⟩ ∈ (𝐴 × {∅}) ↔ (𝑥 ∈ 𝐴 ∧ ∅ ∈ {∅}))
5	3, 4	mpbiran2 708	. . . . . . 7 ⊢ (⟨𝑥, ∅⟩ ∈ (𝐴 × {∅}) ↔ 𝑥 ∈ 𝐴)
6		opelxp 5718	. . . . . . . 8 ⊢ (⟨𝑥, ∅⟩ ∈ (𝐵 × {{∅}}) ↔ (𝑥 ∈ 𝐵 ∧ ∅ ∈ {{∅}}))
7		0nep0 5362	. . . . . . . . . 10 ⊢ ∅ ≠ {∅}
8	2	elsn 4647	. . . . . . . . . 10 ⊢ (∅ ∈ {{∅}} ↔ ∅ = {∅})
9	7, 8	nemtbir 3035	. . . . . . . . 9 ⊢ ¬ ∅ ∈ {{∅}}
10	9	bianfi 532	. . . . . . . 8 ⊢ (∅ ∈ {{∅}} ↔ (𝑥 ∈ 𝐵 ∧ ∅ ∈ {{∅}}))
11	6, 10	bitr4i 277	. . . . . . 7 ⊢ (⟨𝑥, ∅⟩ ∈ (𝐵 × {{∅}}) ↔ ∅ ∈ {{∅}})
12	5, 11	orbi12i 912	. . . . . 6 ⊢ ((⟨𝑥, ∅⟩ ∈ (𝐴 × {∅}) ∨ ⟨𝑥, ∅⟩ ∈ (𝐵 × {{∅}})) ↔ (𝑥 ∈ 𝐴 ∨ ∅ ∈ {{∅}}))
13		elun 4149	. . . . . 6 ⊢ (⟨𝑥, ∅⟩ ∈ ((𝐴 × {∅}) ∪ (𝐵 × {{∅}})) ↔ (⟨𝑥, ∅⟩ ∈ (𝐴 × {∅}) ∨ ⟨𝑥, ∅⟩ ∈ (𝐵 × {{∅}})))
14	9	biorfi 936	. . . . . 6 ⊢ (𝑥 ∈ 𝐴 ↔ (𝑥 ∈ 𝐴 ∨ ∅ ∈ {{∅}}))
15	12, 13, 14	3bitr4ri 303	. . . . 5 ⊢ (𝑥 ∈ 𝐴 ↔ ⟨𝑥, ∅⟩ ∈ ((𝐴 × {∅}) ∪ (𝐵 × {{∅}})))
16		opelxp 5718	. . . . . . . 8 ⊢ (⟨𝑥, ∅⟩ ∈ (𝐶 × {∅}) ↔ (𝑥 ∈ 𝐶 ∧ ∅ ∈ {∅}))
17	3, 16	mpbiran2 708	. . . . . . 7 ⊢ (⟨𝑥, ∅⟩ ∈ (𝐶 × {∅}) ↔ 𝑥 ∈ 𝐶)
18		opelxp 5718	. . . . . . . 8 ⊢ (⟨𝑥, ∅⟩ ∈ (𝐷 × {{∅}}) ↔ (𝑥 ∈ 𝐷 ∧ ∅ ∈ {{∅}}))
19	9	bianfi 532	. . . . . . . 8 ⊢ (∅ ∈ {{∅}} ↔ (𝑥 ∈ 𝐷 ∧ ∅ ∈ {{∅}}))
20	18, 19	bitr4i 277	. . . . . . 7 ⊢ (⟨𝑥, ∅⟩ ∈ (𝐷 × {{∅}}) ↔ ∅ ∈ {{∅}})
21	17, 20	orbi12i 912	. . . . . 6 ⊢ ((⟨𝑥, ∅⟩ ∈ (𝐶 × {∅}) ∨ ⟨𝑥, ∅⟩ ∈ (𝐷 × {{∅}})) ↔ (𝑥 ∈ 𝐶 ∨ ∅ ∈ {{∅}}))
22		elun 4149	. . . . . 6 ⊢ (⟨𝑥, ∅⟩ ∈ ((𝐶 × {∅}) ∪ (𝐷 × {{∅}})) ↔ (⟨𝑥, ∅⟩ ∈ (𝐶 × {∅}) ∨ ⟨𝑥, ∅⟩ ∈ (𝐷 × {{∅}})))
23	9	biorfi 936	. . . . . 6 ⊢ (𝑥 ∈ 𝐶 ↔ (𝑥 ∈ 𝐶 ∨ ∅ ∈ {{∅}}))
24	21, 22, 23	3bitr4ri 303	. . . . 5 ⊢ (𝑥 ∈ 𝐶 ↔ ⟨𝑥, ∅⟩ ∈ ((𝐶 × {∅}) ∪ (𝐷 × {{∅}})))
25	1, 15, 24	3bitr4g 313	. . . 4 ⊢ (((𝐴 × {∅}) ∪ (𝐵 × {{∅}})) = ((𝐶 × {∅}) ∪ (𝐷 × {{∅}})) → (𝑥 ∈ 𝐴 ↔ 𝑥 ∈ 𝐶))
26	25	eqrdv 2726	. . 3 ⊢ (((𝐴 × {∅}) ∪ (𝐵 × {{∅}})) = ((𝐶 × {∅}) ∪ (𝐷 × {{∅}})) → 𝐴 = 𝐶)
27		eleq2 2818	. . . . 5 ⊢ (((𝐴 × {∅}) ∪ (𝐵 × {{∅}})) = ((𝐶 × {∅}) ∪ (𝐷 × {{∅}})) → (⟨𝑥, {∅}⟩ ∈ ((𝐴 × {∅}) ∪ (𝐵 × {{∅}})) ↔ ⟨𝑥, {∅}⟩ ∈ ((𝐶 × {∅}) ∪ (𝐷 × {{∅}}))))
28		opelxp 5718	. . . . . . . 8 ⊢ (⟨𝑥, {∅}⟩ ∈ (𝐴 × {∅}) ↔ (𝑥 ∈ 𝐴 ∧ {∅} ∈ {∅}))
29		snex 5437	. . . . . . . . . . . 12 ⊢ {∅} ∈ V
30	29	elsn 4647	. . . . . . . . . . 11 ⊢ ({∅} ∈ {∅} ↔ {∅} = ∅)
31		eqcom 2735	. . . . . . . . . . 11 ⊢ ({∅} = ∅ ↔ ∅ = {∅})
32	30, 31	bitri 274	. . . . . . . . . 10 ⊢ ({∅} ∈ {∅} ↔ ∅ = {∅})
33	7, 32	nemtbir 3035	. . . . . . . . 9 ⊢ ¬ {∅} ∈ {∅}
34	33	bianfi 532	. . . . . . . 8 ⊢ ({∅} ∈ {∅} ↔ (𝑥 ∈ 𝐴 ∧ {∅} ∈ {∅}))
35	28, 34	bitr4i 277	. . . . . . 7 ⊢ (⟨𝑥, {∅}⟩ ∈ (𝐴 × {∅}) ↔ {∅} ∈ {∅})
36	29	snid 4669	. . . . . . . 8 ⊢ {∅} ∈ {{∅}}
37		opelxp 5718	. . . . . . . 8 ⊢ (⟨𝑥, {∅}⟩ ∈ (𝐵 × {{∅}}) ↔ (𝑥 ∈ 𝐵 ∧ {∅} ∈ {{∅}}))
38	36, 37	mpbiran2 708	. . . . . . 7 ⊢ (⟨𝑥, {∅}⟩ ∈ (𝐵 × {{∅}}) ↔ 𝑥 ∈ 𝐵)
39	35, 38	orbi12i 912	. . . . . 6 ⊢ ((⟨𝑥, {∅}⟩ ∈ (𝐴 × {∅}) ∨ ⟨𝑥, {∅}⟩ ∈ (𝐵 × {{∅}})) ↔ ({∅} ∈ {∅} ∨ 𝑥 ∈ 𝐵))
40		elun 4149	. . . . . 6 ⊢ (⟨𝑥, {∅}⟩ ∈ ((𝐴 × {∅}) ∪ (𝐵 × {{∅}})) ↔ (⟨𝑥, {∅}⟩ ∈ (𝐴 × {∅}) ∨ ⟨𝑥, {∅}⟩ ∈ (𝐵 × {{∅}})))
41		biorf 934	. . . . . . 7 ⊢ (¬ {∅} ∈ {∅} → (𝑥 ∈ 𝐵 ↔ ({∅} ∈ {∅} ∨ 𝑥 ∈ 𝐵)))
42	33, 41	ax-mp 5	. . . . . 6 ⊢ (𝑥 ∈ 𝐵 ↔ ({∅} ∈ {∅} ∨ 𝑥 ∈ 𝐵))
43	39, 40, 42	3bitr4ri 303	. . . . 5 ⊢ (𝑥 ∈ 𝐵 ↔ ⟨𝑥, {∅}⟩ ∈ ((𝐴 × {∅}) ∪ (𝐵 × {{∅}})))
44		opelxp 5718	. . . . . . . 8 ⊢ (⟨𝑥, {∅}⟩ ∈ (𝐶 × {∅}) ↔ (𝑥 ∈ 𝐶 ∧ {∅} ∈ {∅}))
45	33	bianfi 532	. . . . . . . 8 ⊢ ({∅} ∈ {∅} ↔ (𝑥 ∈ 𝐶 ∧ {∅} ∈ {∅}))
46	44, 45	bitr4i 277	. . . . . . 7 ⊢ (⟨𝑥, {∅}⟩ ∈ (𝐶 × {∅}) ↔ {∅} ∈ {∅})
47		opelxp 5718	. . . . . . . 8 ⊢ (⟨𝑥, {∅}⟩ ∈ (𝐷 × {{∅}}) ↔ (𝑥 ∈ 𝐷 ∧ {∅} ∈ {{∅}}))
48	36, 47	mpbiran2 708	. . . . . . 7 ⊢ (⟨𝑥, {∅}⟩ ∈ (𝐷 × {{∅}}) ↔ 𝑥 ∈ 𝐷)
49	46, 48	orbi12i 912	. . . . . 6 ⊢ ((⟨𝑥, {∅}⟩ ∈ (𝐶 × {∅}) ∨ ⟨𝑥, {∅}⟩ ∈ (𝐷 × {{∅}})) ↔ ({∅} ∈ {∅} ∨ 𝑥 ∈ 𝐷))
50		elun 4149	. . . . . 6 ⊢ (⟨𝑥, {∅}⟩ ∈ ((𝐶 × {∅}) ∪ (𝐷 × {{∅}})) ↔ (⟨𝑥, {∅}⟩ ∈ (𝐶 × {∅}) ∨ ⟨𝑥, {∅}⟩ ∈ (𝐷 × {{∅}})))
51		biorf 934	. . . . . . 7 ⊢ (¬ {∅} ∈ {∅} → (𝑥 ∈ 𝐷 ↔ ({∅} ∈ {∅} ∨ 𝑥 ∈ 𝐷)))
52	33, 51	ax-mp 5	. . . . . 6 ⊢ (𝑥 ∈ 𝐷 ↔ ({∅} ∈ {∅} ∨ 𝑥 ∈ 𝐷))
53	49, 50, 52	3bitr4ri 303	. . . . 5 ⊢ (𝑥 ∈ 𝐷 ↔ ⟨𝑥, {∅}⟩ ∈ ((𝐶 × {∅}) ∪ (𝐷 × {{∅}})))
54	27, 43, 53	3bitr4g 313	. . . 4 ⊢ (((𝐴 × {∅}) ∪ (𝐵 × {{∅}})) = ((𝐶 × {∅}) ∪ (𝐷 × {{∅}})) → (𝑥 ∈ 𝐵 ↔ 𝑥 ∈ 𝐷))
55	54	eqrdv 2726	. . 3 ⊢ (((𝐴 × {∅}) ∪ (𝐵 × {{∅}})) = ((𝐶 × {∅}) ∪ (𝐷 × {{∅}})) → 𝐵 = 𝐷)
56	26, 55	jca 510	. 2 ⊢ (((𝐴 × {∅}) ∪ (𝐵 × {{∅}})) = ((𝐶 × {∅}) ∪ (𝐷 × {{∅}})) → (𝐴 = 𝐶 ∧ 𝐵 = 𝐷))
57		xpeq1 5696	. . 3 ⊢ (𝐴 = 𝐶 → (𝐴 × {∅}) = (𝐶 × {∅}))
58		xpeq1 5696	. . 3 ⊢ (𝐵 = 𝐷 → (𝐵 × {{∅}}) = (𝐷 × {{∅}}))
59		uneq12 4159	. . 3 ⊢ (((𝐴 × {∅}) = (𝐶 × {∅}) ∧ (𝐵 × {{∅}}) = (𝐷 × {{∅}})) → ((𝐴 × {∅}) ∪ (𝐵 × {{∅}})) = ((𝐶 × {∅}) ∪ (𝐷 × {{∅}})))
60	57, 58, 59	syl2an 594	. 2 ⊢ ((𝐴 = 𝐶 ∧ 𝐵 = 𝐷) → ((𝐴 × {∅}) ∪ (𝐵 × {{∅}})) = ((𝐶 × {∅}) ∪ (𝐷 × {{∅}})))
61	56, 60	impbii 208	1 ⊢ (((𝐴 × {∅}) ∪ (𝐵 × {{∅}})) = ((𝐶 × {∅}) ∪ (𝐷 × {{∅}})) ↔ (𝐴 = 𝐶 ∧ 𝐵 = 𝐷))

Syntax hints:  ¬ wn 3   ↔ wb 205   ∧ wa 394   ∨ wo 845   = wceq 1533   ∈ wcel 2098   ∪ cun 3947  ∅c0 4326  {csn 4632  ⟨cop 4638   × cxp 5680

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1789  ax-4 1803  ax-5 1905  ax-6 1963  ax-7 2003  ax-8 2100  ax-9 2108  ax-ext 2699  ax-sep 5303  ax-nul 5310  ax-pr 5433

This theorem depends on definitions:  df-bi 206  df-an 395  df-or 846  df-3an 1086  df-tru 1536  df-fal 1546  df-ex 1774  df-sb 2060  df-clab 2706  df-cleq 2720  df-clel 2806  df-ne 2938  df-ral 3059  df-rex 3068  df-rab 3431  df-v 3475  df-dif 3952  df-un 3954  df-in 3956  df-ss 3966  df-nul 4327  df-if 4533  df-sn 4633  df-pr 4635  df-op 4639  df-opab 5215  df-xp 5688

This theorem is referenced by: (None)