Theorem sprsymrelfolem2 48275

Description: Lemma 2 for sprsymrelfo 48279. (Contributed by AV, 23-Nov-2021.)

Hypothesis

Ref	Expression
sprsymrelfo.q	⊢ 𝑄 = {𝑞 ∈ (Pairs‘𝑉) ∣ ∀𝑎 ∈ 𝑉 ∀𝑏 ∈ 𝑉 (𝑞 = {𝑎, 𝑏} → 𝑎𝑅𝑏)}

Assertion

Ref	Expression
sprsymrelfolem2	⊢ ((𝑉 ∈ 𝑊 ∧ 𝑅 ⊆ (𝑉 × 𝑉) ∧ ∀𝑥 ∈ 𝑉 ∀𝑦 ∈ 𝑉 (𝑥𝑅𝑦 ↔ 𝑦𝑅𝑥)) → (𝑥𝑅𝑦 ↔ ∃𝑐 ∈ 𝑄 𝑐 = {𝑥, 𝑦}))

Distinct variable groups:   𝑉,𝑞   𝑄,𝑐   𝑅,𝑎,𝑏,𝑐,𝑞,𝑥,𝑦   𝑉,𝑎,𝑏,𝑐,𝑥,𝑦   𝑊,𝑎,𝑏,𝑐

Allowed substitution hints:   𝑄(𝑥, 𝑦, 𝑞, 𝑎, 𝑏)   𝑊(𝑥, 𝑦, 𝑞)

Proof of Theorem sprsymrelfolem2

Step	Hyp	Ref	Expression
1		df-br 5115	. . . . . . . 8 ⊢ (𝑥𝑅𝑦 ↔ ⟨𝑥, 𝑦⟩ ∈ 𝑅)
2		simpl 488	. . . . . . . . . 10 ⊢ ((𝑉 ∈ 𝑊 ∧ 𝑅 ⊆ (𝑉 × 𝑉)) → 𝑉 ∈ 𝑊)
3		ssel 3934	. . . . . . . . . . . . 13 ⊢ (𝑅 ⊆ (𝑉 × 𝑉) → (⟨𝑥, 𝑦⟩ ∈ 𝑅 → ⟨𝑥, 𝑦⟩ ∈ (𝑉 × 𝑉)))
4	3	adantl 487	. . . . . . . . . . . 12 ⊢ ((𝑉 ∈ 𝑊 ∧ 𝑅 ⊆ (𝑉 × 𝑉)) → (⟨𝑥, 𝑦⟩ ∈ 𝑅 → ⟨𝑥, 𝑦⟩ ∈ (𝑉 × 𝑉)))
5	4	imp 412	. . . . . . . . . . 11 ⊢ (((𝑉 ∈ 𝑊 ∧ 𝑅 ⊆ (𝑉 × 𝑉)) ∧ ⟨𝑥, 𝑦⟩ ∈ 𝑅) → ⟨𝑥, 𝑦⟩ ∈ (𝑉 × 𝑉))
6		opelxp 5702	. . . . . . . . . . 11 ⊢ (⟨𝑥, 𝑦⟩ ∈ (𝑉 × 𝑉) ↔ (𝑥 ∈ 𝑉 ∧ 𝑦 ∈ 𝑉))
7	5, 6	sylib 221	. . . . . . . . . 10 ⊢ (((𝑉 ∈ 𝑊 ∧ 𝑅 ⊆ (𝑉 × 𝑉)) ∧ ⟨𝑥, 𝑦⟩ ∈ 𝑅) → (𝑥 ∈ 𝑉 ∧ 𝑦 ∈ 𝑉))
8		prelspr 48268	. . . . . . . . . 10 ⊢ ((𝑉 ∈ 𝑊 ∧ (𝑥 ∈ 𝑉 ∧ 𝑦 ∈ 𝑉)) → {𝑥, 𝑦} ∈ (Pairs‘𝑉))
9	2, 7, 8	syl2an2r 698	. . . . . . . . 9 ⊢ (((𝑉 ∈ 𝑊 ∧ 𝑅 ⊆ (𝑉 × 𝑉)) ∧ ⟨𝑥, 𝑦⟩ ∈ 𝑅) → {𝑥, 𝑦} ∈ (Pairs‘𝑉))
10	9	ex 418	. . . . . . . 8 ⊢ ((𝑉 ∈ 𝑊 ∧ 𝑅 ⊆ (𝑉 × 𝑉)) → (⟨𝑥, 𝑦⟩ ∈ 𝑅 → {𝑥, 𝑦} ∈ (Pairs‘𝑉)))
11	1, 10	biimtrid 245	. . . . . . 7 ⊢ ((𝑉 ∈ 𝑊 ∧ 𝑅 ⊆ (𝑉 × 𝑉)) → (𝑥𝑅𝑦 → {𝑥, 𝑦} ∈ (Pairs‘𝑉)))
12	11	3adant3 1150	. . . . . 6 ⊢ ((𝑉 ∈ 𝑊 ∧ 𝑅 ⊆ (𝑉 × 𝑉) ∧ ∀𝑥 ∈ 𝑉 ∀𝑦 ∈ 𝑉 (𝑥𝑅𝑦 ↔ 𝑦𝑅𝑥)) → (𝑥𝑅𝑦 → {𝑥, 𝑦} ∈ (Pairs‘𝑉)))
13	12	imp 412	. . . . 5 ⊢ (((𝑉 ∈ 𝑊 ∧ 𝑅 ⊆ (𝑉 × 𝑉) ∧ ∀𝑥 ∈ 𝑉 ∀𝑦 ∈ 𝑉 (𝑥𝑅𝑦 ↔ 𝑦𝑅𝑥)) ∧ 𝑥𝑅𝑦) → {𝑥, 𝑦} ∈ (Pairs‘𝑉))
14		vex 3462	. . . . . . . 8 ⊢ 𝑥 ∈ V
15		vex 3462	. . . . . . . 8 ⊢ 𝑦 ∈ V
16		vex 3462	. . . . . . . 8 ⊢ 𝑎 ∈ V
17		vex 3462	. . . . . . . 8 ⊢ 𝑏 ∈ V
18	14, 15, 16, 17	preq12b 4820	. . . . . . 7 ⊢ ({𝑥, 𝑦} = {𝑎, 𝑏} ↔ ((𝑥 = 𝑎 ∧ 𝑦 = 𝑏) ∨ (𝑥 = 𝑏 ∧ 𝑦 = 𝑎)))
19		breq12 5119	. . . . . . . . . . . . . 14 ⊢ ((𝑥 = 𝑎 ∧ 𝑦 = 𝑏) → (𝑥𝑅𝑦 ↔ 𝑎𝑅𝑏))
20	19	biimpd 232	. . . . . . . . . . . . 13 ⊢ ((𝑥 = 𝑎 ∧ 𝑦 = 𝑏) → (𝑥𝑅𝑦 → 𝑎𝑅𝑏))
21	20	com12 33	. . . . . . . . . . . 12 ⊢ (𝑥𝑅𝑦 → ((𝑥 = 𝑎 ∧ 𝑦 = 𝑏) → 𝑎𝑅𝑏))
22	21	adantl 487	. . . . . . . . . . 11 ⊢ (((𝑉 ∈ 𝑊 ∧ 𝑅 ⊆ (𝑉 × 𝑉) ∧ ∀𝑥 ∈ 𝑉 ∀𝑦 ∈ 𝑉 (𝑥𝑅𝑦 ↔ 𝑦𝑅𝑥)) ∧ 𝑥𝑅𝑦) → ((𝑥 = 𝑎 ∧ 𝑦 = 𝑏) → 𝑎𝑅𝑏))
23	22	adantr 486	. . . . . . . . . 10 ⊢ ((((𝑉 ∈ 𝑊 ∧ 𝑅 ⊆ (𝑉 × 𝑉) ∧ ∀𝑥 ∈ 𝑉 ∀𝑦 ∈ 𝑉 (𝑥𝑅𝑦 ↔ 𝑦𝑅𝑥)) ∧ 𝑥𝑅𝑦) ∧ (𝑎 ∈ 𝑉 ∧ 𝑏 ∈ 𝑉)) → ((𝑥 = 𝑎 ∧ 𝑦 = 𝑏) → 𝑎𝑅𝑏))
24	23	com12 33	. . . . . . . . 9 ⊢ ((𝑥 = 𝑎 ∧ 𝑦 = 𝑏) → ((((𝑉 ∈ 𝑊 ∧ 𝑅 ⊆ (𝑉 × 𝑉) ∧ ∀𝑥 ∈ 𝑉 ∀𝑦 ∈ 𝑉 (𝑥𝑅𝑦 ↔ 𝑦𝑅𝑥)) ∧ 𝑥𝑅𝑦) ∧ (𝑎 ∈ 𝑉 ∧ 𝑏 ∈ 𝑉)) → 𝑎𝑅𝑏))
25		rsp2 3285	. . . . . . . . . . . . . . . . . . 19 ⊢ (∀𝑥 ∈ 𝑉 ∀𝑦 ∈ 𝑉 (𝑥𝑅𝑦 ↔ 𝑦𝑅𝑥) → ((𝑥 ∈ 𝑉 ∧ 𝑦 ∈ 𝑉) → (𝑥𝑅𝑦 ↔ 𝑦𝑅𝑥)))
26	25	ancomsd 471	. . . . . . . . . . . . . . . . . 18 ⊢ (∀𝑥 ∈ 𝑉 ∀𝑦 ∈ 𝑉 (𝑥𝑅𝑦 ↔ 𝑦𝑅𝑥) → ((𝑦 ∈ 𝑉 ∧ 𝑥 ∈ 𝑉) → (𝑥𝑅𝑦 ↔ 𝑦𝑅𝑥)))
27	26	imp 412	. . . . . . . . . . . . . . . . 17 ⊢ ((∀𝑥 ∈ 𝑉 ∀𝑦 ∈ 𝑉 (𝑥𝑅𝑦 ↔ 𝑦𝑅𝑥) ∧ (𝑦 ∈ 𝑉 ∧ 𝑥 ∈ 𝑉)) → (𝑥𝑅𝑦 ↔ 𝑦𝑅𝑥))
28	27	biimpd 232	. . . . . . . . . . . . . . . 16 ⊢ ((∀𝑥 ∈ 𝑉 ∀𝑦 ∈ 𝑉 (𝑥𝑅𝑦 ↔ 𝑦𝑅𝑥) ∧ (𝑦 ∈ 𝑉 ∧ 𝑥 ∈ 𝑉)) → (𝑥𝑅𝑦 → 𝑦𝑅𝑥))
29	28	ex 418	. . . . . . . . . . . . . . 15 ⊢ (∀𝑥 ∈ 𝑉 ∀𝑦 ∈ 𝑉 (𝑥𝑅𝑦 ↔ 𝑦𝑅𝑥) → ((𝑦 ∈ 𝑉 ∧ 𝑥 ∈ 𝑉) → (𝑥𝑅𝑦 → 𝑦𝑅𝑥)))
30	29	3ad2ant3 1153	. . . . . . . . . . . . . 14 ⊢ ((𝑉 ∈ 𝑊 ∧ 𝑅 ⊆ (𝑉 × 𝑉) ∧ ∀𝑥 ∈ 𝑉 ∀𝑦 ∈ 𝑉 (𝑥𝑅𝑦 ↔ 𝑦𝑅𝑥)) → ((𝑦 ∈ 𝑉 ∧ 𝑥 ∈ 𝑉) → (𝑥𝑅𝑦 → 𝑦𝑅𝑥)))
31	30	com23 87	. . . . . . . . . . . . 13 ⊢ ((𝑉 ∈ 𝑊 ∧ 𝑅 ⊆ (𝑉 × 𝑉) ∧ ∀𝑥 ∈ 𝑉 ∀𝑦 ∈ 𝑉 (𝑥𝑅𝑦 ↔ 𝑦𝑅𝑥)) → (𝑥𝑅𝑦 → ((𝑦 ∈ 𝑉 ∧ 𝑥 ∈ 𝑉) → 𝑦𝑅𝑥)))
32	31	imp 412	. . . . . . . . . . . 12 ⊢ (((𝑉 ∈ 𝑊 ∧ 𝑅 ⊆ (𝑉 × 𝑉) ∧ ∀𝑥 ∈ 𝑉 ∀𝑦 ∈ 𝑉 (𝑥𝑅𝑦 ↔ 𝑦𝑅𝑥)) ∧ 𝑥𝑅𝑦) → ((𝑦 ∈ 𝑉 ∧ 𝑥 ∈ 𝑉) → 𝑦𝑅𝑥))
33	32	adantl 487	. . . . . . . . . . 11 ⊢ (((𝑥 = 𝑏 ∧ 𝑦 = 𝑎) ∧ ((𝑉 ∈ 𝑊 ∧ 𝑅 ⊆ (𝑉 × 𝑉) ∧ ∀𝑥 ∈ 𝑉 ∀𝑦 ∈ 𝑉 (𝑥𝑅𝑦 ↔ 𝑦𝑅𝑥)) ∧ 𝑥𝑅𝑦)) → ((𝑦 ∈ 𝑉 ∧ 𝑥 ∈ 𝑉) → 𝑦𝑅𝑥))
34		eleq1 2854	. . . . . . . . . . . . . 14 ⊢ (𝑦 = 𝑎 → (𝑦 ∈ 𝑉 ↔ 𝑎 ∈ 𝑉))
35		eleq1 2854	. . . . . . . . . . . . . 14 ⊢ (𝑥 = 𝑏 → (𝑥 ∈ 𝑉 ↔ 𝑏 ∈ 𝑉))
36	34, 35	bi2anan9r 651	. . . . . . . . . . . . 13 ⊢ ((𝑥 = 𝑏 ∧ 𝑦 = 𝑎) → ((𝑦 ∈ 𝑉 ∧ 𝑥 ∈ 𝑉) ↔ (𝑎 ∈ 𝑉 ∧ 𝑏 ∈ 𝑉)))
37		breq12 5119	. . . . . . . . . . . . . 14 ⊢ ((𝑦 = 𝑎 ∧ 𝑥 = 𝑏) → (𝑦𝑅𝑥 ↔ 𝑎𝑅𝑏))
38	37	ancoms 464	. . . . . . . . . . . . 13 ⊢ ((𝑥 = 𝑏 ∧ 𝑦 = 𝑎) → (𝑦𝑅𝑥 ↔ 𝑎𝑅𝑏))
39	36, 38	imbi12d 347	. . . . . . . . . . . 12 ⊢ ((𝑥 = 𝑏 ∧ 𝑦 = 𝑎) → (((𝑦 ∈ 𝑉 ∧ 𝑥 ∈ 𝑉) → 𝑦𝑅𝑥) ↔ ((𝑎 ∈ 𝑉 ∧ 𝑏 ∈ 𝑉) → 𝑎𝑅𝑏)))
40	39	adantr 486	. . . . . . . . . . 11 ⊢ (((𝑥 = 𝑏 ∧ 𝑦 = 𝑎) ∧ ((𝑉 ∈ 𝑊 ∧ 𝑅 ⊆ (𝑉 × 𝑉) ∧ ∀𝑥 ∈ 𝑉 ∀𝑦 ∈ 𝑉 (𝑥𝑅𝑦 ↔ 𝑦𝑅𝑥)) ∧ 𝑥𝑅𝑦)) → (((𝑦 ∈ 𝑉 ∧ 𝑥 ∈ 𝑉) → 𝑦𝑅𝑥) ↔ ((𝑎 ∈ 𝑉 ∧ 𝑏 ∈ 𝑉) → 𝑎𝑅𝑏)))
41	33, 40	mpbid 235	. . . . . . . . . 10 ⊢ (((𝑥 = 𝑏 ∧ 𝑦 = 𝑎) ∧ ((𝑉 ∈ 𝑊 ∧ 𝑅 ⊆ (𝑉 × 𝑉) ∧ ∀𝑥 ∈ 𝑉 ∀𝑦 ∈ 𝑉 (𝑥𝑅𝑦 ↔ 𝑦𝑅𝑥)) ∧ 𝑥𝑅𝑦)) → ((𝑎 ∈ 𝑉 ∧ 𝑏 ∈ 𝑉) → 𝑎𝑅𝑏))
42	41	expimpd 459	. . . . . . . . 9 ⊢ ((𝑥 = 𝑏 ∧ 𝑦 = 𝑎) → ((((𝑉 ∈ 𝑊 ∧ 𝑅 ⊆ (𝑉 × 𝑉) ∧ ∀𝑥 ∈ 𝑉 ∀𝑦 ∈ 𝑉 (𝑥𝑅𝑦 ↔ 𝑦𝑅𝑥)) ∧ 𝑥𝑅𝑦) ∧ (𝑎 ∈ 𝑉 ∧ 𝑏 ∈ 𝑉)) → 𝑎𝑅𝑏))
43	24, 42	jaoi 871	. . . . . . . 8 ⊢ (((𝑥 = 𝑎 ∧ 𝑦 = 𝑏) ∨ (𝑥 = 𝑏 ∧ 𝑦 = 𝑎)) → ((((𝑉 ∈ 𝑊 ∧ 𝑅 ⊆ (𝑉 × 𝑉) ∧ ∀𝑥 ∈ 𝑉 ∀𝑦 ∈ 𝑉 (𝑥𝑅𝑦 ↔ 𝑦𝑅𝑥)) ∧ 𝑥𝑅𝑦) ∧ (𝑎 ∈ 𝑉 ∧ 𝑏 ∈ 𝑉)) → 𝑎𝑅𝑏))
44	43	com12 33	. . . . . . 7 ⊢ ((((𝑉 ∈ 𝑊 ∧ 𝑅 ⊆ (𝑉 × 𝑉) ∧ ∀𝑥 ∈ 𝑉 ∀𝑦 ∈ 𝑉 (𝑥𝑅𝑦 ↔ 𝑦𝑅𝑥)) ∧ 𝑥𝑅𝑦) ∧ (𝑎 ∈ 𝑉 ∧ 𝑏 ∈ 𝑉)) → (((𝑥 = 𝑎 ∧ 𝑦 = 𝑏) ∨ (𝑥 = 𝑏 ∧ 𝑦 = 𝑎)) → 𝑎𝑅𝑏))
45	18, 44	biimtrid 245	. . . . . 6 ⊢ ((((𝑉 ∈ 𝑊 ∧ 𝑅 ⊆ (𝑉 × 𝑉) ∧ ∀𝑥 ∈ 𝑉 ∀𝑦 ∈ 𝑉 (𝑥𝑅𝑦 ↔ 𝑦𝑅𝑥)) ∧ 𝑥𝑅𝑦) ∧ (𝑎 ∈ 𝑉 ∧ 𝑏 ∈ 𝑉)) → ({𝑥, 𝑦} = {𝑎, 𝑏} → 𝑎𝑅𝑏))
46	45	ralrimivva 3211	. . . . 5 ⊢ (((𝑉 ∈ 𝑊 ∧ 𝑅 ⊆ (𝑉 × 𝑉) ∧ ∀𝑥 ∈ 𝑉 ∀𝑦 ∈ 𝑉 (𝑥𝑅𝑦 ↔ 𝑦𝑅𝑥)) ∧ 𝑥𝑅𝑦) → ∀𝑎 ∈ 𝑉 ∀𝑏 ∈ 𝑉 ({𝑥, 𝑦} = {𝑎, 𝑏} → 𝑎𝑅𝑏))
47		sprsymrelfo.q	. . . . . . 7 ⊢ 𝑄 = {𝑞 ∈ (Pairs‘𝑉) ∣ ∀𝑎 ∈ 𝑉 ∀𝑏 ∈ 𝑉 (𝑞 = {𝑎, 𝑏} → 𝑎𝑅𝑏)}
48	47	eleq2i 2858	. . . . . 6 ⊢ ({𝑥, 𝑦} ∈ 𝑄 ↔ {𝑥, 𝑦} ∈ {𝑞 ∈ (Pairs‘𝑉) ∣ ∀𝑎 ∈ 𝑉 ∀𝑏 ∈ 𝑉 (𝑞 = {𝑎, 𝑏} → 𝑎𝑅𝑏)})
49		eqeq1 2770	. . . . . . . . 9 ⊢ (𝑞 = {𝑥, 𝑦} → (𝑞 = {𝑎, 𝑏} ↔ {𝑥, 𝑦} = {𝑎, 𝑏}))
50	49	imbi1d 344	. . . . . . . 8 ⊢ (𝑞 = {𝑥, 𝑦} → ((𝑞 = {𝑎, 𝑏} → 𝑎𝑅𝑏) ↔ ({𝑥, 𝑦} = {𝑎, 𝑏} → 𝑎𝑅𝑏)))
51	50	2ralbidv 3232	. . . . . . 7 ⊢ (𝑞 = {𝑥, 𝑦} → (∀𝑎 ∈ 𝑉 ∀𝑏 ∈ 𝑉 (𝑞 = {𝑎, 𝑏} → 𝑎𝑅𝑏) ↔ ∀𝑎 ∈ 𝑉 ∀𝑏 ∈ 𝑉 ({𝑥, 𝑦} = {𝑎, 𝑏} → 𝑎𝑅𝑏)))
52	51	elrab 3653	. . . . . 6 ⊢ ({𝑥, 𝑦} ∈ {𝑞 ∈ (Pairs‘𝑉) ∣ ∀𝑎 ∈ 𝑉 ∀𝑏 ∈ 𝑉 (𝑞 = {𝑎, 𝑏} → 𝑎𝑅𝑏)} ↔ ({𝑥, 𝑦} ∈ (Pairs‘𝑉) ∧ ∀𝑎 ∈ 𝑉 ∀𝑏 ∈ 𝑉 ({𝑥, 𝑦} = {𝑎, 𝑏} → 𝑎𝑅𝑏)))
53	48, 52	bitri 278	. . . . 5 ⊢ ({𝑥, 𝑦} ∈ 𝑄 ↔ ({𝑥, 𝑦} ∈ (Pairs‘𝑉) ∧ ∀𝑎 ∈ 𝑉 ∀𝑏 ∈ 𝑉 ({𝑥, 𝑦} = {𝑎, 𝑏} → 𝑎𝑅𝑏)))
54	13, 46, 53	sylanbrc 595	. . . 4 ⊢ (((𝑉 ∈ 𝑊 ∧ 𝑅 ⊆ (𝑉 × 𝑉) ∧ ∀𝑥 ∈ 𝑉 ∀𝑦 ∈ 𝑉 (𝑥𝑅𝑦 ↔ 𝑦𝑅𝑥)) ∧ 𝑥𝑅𝑦) → {𝑥, 𝑦} ∈ 𝑄)
55		eqidd 2767	. . . 4 ⊢ (((𝑉 ∈ 𝑊 ∧ 𝑅 ⊆ (𝑉 × 𝑉) ∧ ∀𝑥 ∈ 𝑉 ∀𝑦 ∈ 𝑉 (𝑥𝑅𝑦 ↔ 𝑦𝑅𝑥)) ∧ 𝑥𝑅𝑦) → {𝑥, 𝑦} = {𝑥, 𝑦})
56		eqeq1 2770	. . . . 5 ⊢ (𝑐 = {𝑥, 𝑦} → (𝑐 = {𝑥, 𝑦} ↔ {𝑥, 𝑦} = {𝑥, 𝑦}))
57	56	rspcev 3584	. . . 4 ⊢ (({𝑥, 𝑦} ∈ 𝑄 ∧ {𝑥, 𝑦} = {𝑥, 𝑦}) → ∃𝑐 ∈ 𝑄 𝑐 = {𝑥, 𝑦})
58	54, 55, 57	syl2anc 596	. . 3 ⊢ (((𝑉 ∈ 𝑊 ∧ 𝑅 ⊆ (𝑉 × 𝑉) ∧ ∀𝑥 ∈ 𝑉 ∀𝑦 ∈ 𝑉 (𝑥𝑅𝑦 ↔ 𝑦𝑅𝑥)) ∧ 𝑥𝑅𝑦) → ∃𝑐 ∈ 𝑄 𝑐 = {𝑥, 𝑦})
59	58	ex 418	. 2 ⊢ ((𝑉 ∈ 𝑊 ∧ 𝑅 ⊆ (𝑉 × 𝑉) ∧ ∀𝑥 ∈ 𝑉 ∀𝑦 ∈ 𝑉 (𝑥𝑅𝑦 ↔ 𝑦𝑅𝑥)) → (𝑥𝑅𝑦 → ∃𝑐 ∈ 𝑄 𝑐 = {𝑥, 𝑦}))
60	47	eleq2i 2858	. . . . . 6 ⊢ (𝑐 ∈ 𝑄 ↔ 𝑐 ∈ {𝑞 ∈ (Pairs‘𝑉) ∣ ∀𝑎 ∈ 𝑉 ∀𝑏 ∈ 𝑉 (𝑞 = {𝑎, 𝑏} → 𝑎𝑅𝑏)})
61		eqeq1 2770	. . . . . . . . 9 ⊢ (𝑞 = 𝑐 → (𝑞 = {𝑎, 𝑏} ↔ 𝑐 = {𝑎, 𝑏}))
62	61	imbi1d 344	. . . . . . . 8 ⊢ (𝑞 = 𝑐 → ((𝑞 = {𝑎, 𝑏} → 𝑎𝑅𝑏) ↔ (𝑐 = {𝑎, 𝑏} → 𝑎𝑅𝑏)))
63	62	2ralbidv 3232	. . . . . . 7 ⊢ (𝑞 = 𝑐 → (∀𝑎 ∈ 𝑉 ∀𝑏 ∈ 𝑉 (𝑞 = {𝑎, 𝑏} → 𝑎𝑅𝑏) ↔ ∀𝑎 ∈ 𝑉 ∀𝑏 ∈ 𝑉 (𝑐 = {𝑎, 𝑏} → 𝑎𝑅𝑏)))
64	63	elrab 3653	. . . . . 6 ⊢ (𝑐 ∈ {𝑞 ∈ (Pairs‘𝑉) ∣ ∀𝑎 ∈ 𝑉 ∀𝑏 ∈ 𝑉 (𝑞 = {𝑎, 𝑏} → 𝑎𝑅𝑏)} ↔ (𝑐 ∈ (Pairs‘𝑉) ∧ ∀𝑎 ∈ 𝑉 ∀𝑏 ∈ 𝑉 (𝑐 = {𝑎, 𝑏} → 𝑎𝑅𝑏)))
65	60, 64	bitri 278	. . . . 5 ⊢ (𝑐 ∈ 𝑄 ↔ (𝑐 ∈ (Pairs‘𝑉) ∧ ∀𝑎 ∈ 𝑉 ∀𝑏 ∈ 𝑉 (𝑐 = {𝑎, 𝑏} → 𝑎𝑅𝑏)))
66		eleq1 2854	. . . . . . . . . . 11 ⊢ (𝑐 = {𝑥, 𝑦} → (𝑐 ∈ (Pairs‘𝑉) ↔ {𝑥, 𝑦} ∈ (Pairs‘𝑉)))
67		prsprel 48269	. . . . . . . . . . . 12 ⊢ (({𝑥, 𝑦} ∈ (Pairs‘𝑉) ∧ (𝑥 ∈ V ∧ 𝑦 ∈ V)) → (𝑥 ∈ 𝑉 ∧ 𝑦 ∈ 𝑉))
68	14, 15, 67	mpanr12 718	. . . . . . . . . . 11 ⊢ ({𝑥, 𝑦} ∈ (Pairs‘𝑉) → (𝑥 ∈ 𝑉 ∧ 𝑦 ∈ 𝑉))
69	66, 68	biimtrdi 256	. . . . . . . . . 10 ⊢ (𝑐 = {𝑥, 𝑦} → (𝑐 ∈ (Pairs‘𝑉) → (𝑥 ∈ 𝑉 ∧ 𝑦 ∈ 𝑉)))
70	69	com12 33	. . . . . . . . 9 ⊢ (𝑐 ∈ (Pairs‘𝑉) → (𝑐 = {𝑥, 𝑦} → (𝑥 ∈ 𝑉 ∧ 𝑦 ∈ 𝑉)))
71	70	adantr 486	. . . . . . . 8 ⊢ ((𝑐 ∈ (Pairs‘𝑉) ∧ ∀𝑎 ∈ 𝑉 ∀𝑏 ∈ 𝑉 (𝑐 = {𝑎, 𝑏} → 𝑎𝑅𝑏)) → (𝑐 = {𝑥, 𝑦} → (𝑥 ∈ 𝑉 ∧ 𝑦 ∈ 𝑉)))
72	71	imp 412	. . . . . . 7 ⊢ (((𝑐 ∈ (Pairs‘𝑉) ∧ ∀𝑎 ∈ 𝑉 ∀𝑏 ∈ 𝑉 (𝑐 = {𝑎, 𝑏} → 𝑎𝑅𝑏)) ∧ 𝑐 = {𝑥, 𝑦}) → (𝑥 ∈ 𝑉 ∧ 𝑦 ∈ 𝑉))
73		preq1 4704	. . . . . . . . . . . 12 ⊢ (𝑎 = 𝑥 → {𝑎, 𝑏} = {𝑥, 𝑏})
74	73	eqeq2d 2777	. . . . . . . . . . 11 ⊢ (𝑎 = 𝑥 → (𝑐 = {𝑎, 𝑏} ↔ 𝑐 = {𝑥, 𝑏}))
75		breq1 5117	. . . . . . . . . . 11 ⊢ (𝑎 = 𝑥 → (𝑎𝑅𝑏 ↔ 𝑥𝑅𝑏))
76	74, 75	imbi12d 347	. . . . . . . . . 10 ⊢ (𝑎 = 𝑥 → ((𝑐 = {𝑎, 𝑏} → 𝑎𝑅𝑏) ↔ (𝑐 = {𝑥, 𝑏} → 𝑥𝑅𝑏)))
77		preq2 4705	. . . . . . . . . . . 12 ⊢ (𝑏 = 𝑦 → {𝑥, 𝑏} = {𝑥, 𝑦})
78	77	eqeq2d 2777	. . . . . . . . . . 11 ⊢ (𝑏 = 𝑦 → (𝑐 = {𝑥, 𝑏} ↔ 𝑐 = {𝑥, 𝑦}))
79		breq2 5118	. . . . . . . . . . 11 ⊢ (𝑏 = 𝑦 → (𝑥𝑅𝑏 ↔ 𝑥𝑅𝑦))
80	78, 79	imbi12d 347	. . . . . . . . . 10 ⊢ (𝑏 = 𝑦 → ((𝑐 = {𝑥, 𝑏} → 𝑥𝑅𝑏) ↔ (𝑐 = {𝑥, 𝑦} → 𝑥𝑅𝑦)))
81	76, 80	rspc2v 3595	. . . . . . . . 9 ⊢ ((𝑥 ∈ 𝑉 ∧ 𝑦 ∈ 𝑉) → (∀𝑎 ∈ 𝑉 ∀𝑏 ∈ 𝑉 (𝑐 = {𝑎, 𝑏} → 𝑎𝑅𝑏) → (𝑐 = {𝑥, 𝑦} → 𝑥𝑅𝑦)))
82	81	a1d 26	. . . . . . . 8 ⊢ ((𝑥 ∈ 𝑉 ∧ 𝑦 ∈ 𝑉) → (𝑐 ∈ (Pairs‘𝑉) → (∀𝑎 ∈ 𝑉 ∀𝑏 ∈ 𝑉 (𝑐 = {𝑎, 𝑏} → 𝑎𝑅𝑏) → (𝑐 = {𝑥, 𝑦} → 𝑥𝑅𝑦))))
83	82	imp4c 429	. . . . . . 7 ⊢ ((𝑥 ∈ 𝑉 ∧ 𝑦 ∈ 𝑉) → (((𝑐 ∈ (Pairs‘𝑉) ∧ ∀𝑎 ∈ 𝑉 ∀𝑏 ∈ 𝑉 (𝑐 = {𝑎, 𝑏} → 𝑎𝑅𝑏)) ∧ 𝑐 = {𝑥, 𝑦}) → 𝑥𝑅𝑦))
84	72, 83	mpcom 39	. . . . . 6 ⊢ (((𝑐 ∈ (Pairs‘𝑉) ∧ ∀𝑎 ∈ 𝑉 ∀𝑏 ∈ 𝑉 (𝑐 = {𝑎, 𝑏} → 𝑎𝑅𝑏)) ∧ 𝑐 = {𝑥, 𝑦}) → 𝑥𝑅𝑦)
85	84	a1d 26	. . . . 5 ⊢ (((𝑐 ∈ (Pairs‘𝑉) ∧ ∀𝑎 ∈ 𝑉 ∀𝑏 ∈ 𝑉 (𝑐 = {𝑎, 𝑏} → 𝑎𝑅𝑏)) ∧ 𝑐 = {𝑥, 𝑦}) → ((𝑉 ∈ 𝑊 ∧ 𝑅 ⊆ (𝑉 × 𝑉) ∧ ∀𝑥 ∈ 𝑉 ∀𝑦 ∈ 𝑉 (𝑥𝑅𝑦 ↔ 𝑦𝑅𝑥)) → 𝑥𝑅𝑦))
86	65, 85	sylanb 593	. . . 4 ⊢ ((𝑐 ∈ 𝑄 ∧ 𝑐 = {𝑥, 𝑦}) → ((𝑉 ∈ 𝑊 ∧ 𝑅 ⊆ (𝑉 × 𝑉) ∧ ∀𝑥 ∈ 𝑉 ∀𝑦 ∈ 𝑉 (𝑥𝑅𝑦 ↔ 𝑦𝑅𝑥)) → 𝑥𝑅𝑦))
87	86	rexlimiva 3161	. . 3 ⊢ (∃𝑐 ∈ 𝑄 𝑐 = {𝑥, 𝑦} → ((𝑉 ∈ 𝑊 ∧ 𝑅 ⊆ (𝑉 × 𝑉) ∧ ∀𝑥 ∈ 𝑉 ∀𝑦 ∈ 𝑉 (𝑥𝑅𝑦 ↔ 𝑦𝑅𝑥)) → 𝑥𝑅𝑦))
88	87	com12 33	. 2 ⊢ ((𝑉 ∈ 𝑊 ∧ 𝑅 ⊆ (𝑉 × 𝑉) ∧ ∀𝑥 ∈ 𝑉 ∀𝑦 ∈ 𝑉 (𝑥𝑅𝑦 ↔ 𝑦𝑅𝑥)) → (∃𝑐 ∈ 𝑄 𝑐 = {𝑥, 𝑦} → 𝑥𝑅𝑦))
89	59, 88	impbid 215	1 ⊢ ((𝑉 ∈ 𝑊 ∧ 𝑅 ⊆ (𝑉 × 𝑉) ∧ ∀𝑥 ∈ 𝑉 ∀𝑦 ∈ 𝑉 (𝑥𝑅𝑦 ↔ 𝑦𝑅𝑥)) → (𝑥𝑅𝑦 ↔ ∃𝑐 ∈ 𝑄 𝑐 = {𝑥, 𝑦}))

This proof depends on syntax axioms:   → wi 4   ↔ wb 209   ∧ wa 401   ∨ wo 861   ∧ w3a 1103   = wceq 1570   ∈ wcel 2146  ∀wral 3082  ∃wrex 3092  {crab 3419  Vcvv 3458   ⊆ wss 3908  {cpr 4596  ⟨cop 4600   class class class wbr 5114   × cxp 5664  ‘cfv 6543  Pairscspr 48259

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 2148  ax-9 2156  ax-10 2179  ax-11 2195  ax-12 2216  ax-ext 2738  ax-rep 5243  ax-sep 5262  ax-nul 5274  ax-pr 5409  ax-un 7745

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-mo 2570  df-eu 2600  df-clab 2745  df-cleq 2758  df-clel 2841  df-nfc 2915  df-ne 2962  df-ral 3083  df-rex 3093  df-rab 3420  df-v 3460  df-sbc 3748  df-csb 3857  df-dif 3911  df-un 3913  df-in 3915  df-ss 3925  df-nul 4290  df-if 4493  df-pw 4569  df-sn 4595  df-pr 4597  df-op 4601  df-uni 4878  df-iun 4963  df-br 5115  df-opab 5179  df-mpt 5198  df-id 5561  df-xp 5672  df-rel 5673  df-cnv 5674  df-co 5675  df-dm 5676  df-iota 6499  df-fun 6545  df-fv 6551  df-spr 48260

This theorem is used by:  sprsymrelfo  48279