Theorem prsprel 48277

Description: The elements of a pair from the set of all unordered pairs over a given set 𝑉 are elements of the set 𝑉. (Contributed by AV, 22-Nov-2021.)

Assertion

Ref	Expression
prsprel	⊢ (({𝑋, 𝑌} ∈ (Pairs‘𝑉) ∧ (𝑋 ∈ 𝑈 ∧ 𝑌 ∈ 𝑊)) → (𝑋 ∈ 𝑉 ∧ 𝑌 ∈ 𝑉))

Proof of Theorem prsprel

Dummy variables 𝑎 𝑏 are mutually distinct and distinct from all other variables.

Step	Hyp	Ref	Expression
1		sprel 48274	. . 3 ⊢ ({𝑋, 𝑌} ∈ (Pairs‘𝑉) → ∃𝑎 ∈ 𝑉 ∃𝑏 ∈ 𝑉 {𝑋, 𝑌} = {𝑎, 𝑏})
2		preq12bg 4823	. . . . . . 7 ⊢ (((𝑋 ∈ 𝑈 ∧ 𝑌 ∈ 𝑊) ∧ (𝑎 ∈ 𝑉 ∧ 𝑏 ∈ 𝑉)) → ({𝑋, 𝑌} = {𝑎, 𝑏} ↔ ((𝑋 = 𝑎 ∧ 𝑌 = 𝑏) ∨ (𝑋 = 𝑏 ∧ 𝑌 = 𝑎))))
3		eleq1 2854	. . . . . . . . . . . . 13 ⊢ (𝑎 = 𝑋 → (𝑎 ∈ 𝑉 ↔ 𝑋 ∈ 𝑉))
4	3	eqcoms 2774	. . . . . . . . . . . 12 ⊢ (𝑋 = 𝑎 → (𝑎 ∈ 𝑉 ↔ 𝑋 ∈ 𝑉))
5		eleq1 2854	. . . . . . . . . . . . 13 ⊢ (𝑏 = 𝑌 → (𝑏 ∈ 𝑉 ↔ 𝑌 ∈ 𝑉))
6	5	eqcoms 2774	. . . . . . . . . . . 12 ⊢ (𝑌 = 𝑏 → (𝑏 ∈ 𝑉 ↔ 𝑌 ∈ 𝑉))
7	4, 6	bi2anan9 650	. . . . . . . . . . 11 ⊢ ((𝑋 = 𝑎 ∧ 𝑌 = 𝑏) → ((𝑎 ∈ 𝑉 ∧ 𝑏 ∈ 𝑉) ↔ (𝑋 ∈ 𝑉 ∧ 𝑌 ∈ 𝑉)))
8	7	biimpd 232	. . . . . . . . . 10 ⊢ ((𝑋 = 𝑎 ∧ 𝑌 = 𝑏) → ((𝑎 ∈ 𝑉 ∧ 𝑏 ∈ 𝑉) → (𝑋 ∈ 𝑉 ∧ 𝑌 ∈ 𝑉)))
9		eleq1 2854	. . . . . . . . . . . . . 14 ⊢ (𝑏 = 𝑋 → (𝑏 ∈ 𝑉 ↔ 𝑋 ∈ 𝑉))
10	9	eqcoms 2774	. . . . . . . . . . . . 13 ⊢ (𝑋 = 𝑏 → (𝑏 ∈ 𝑉 ↔ 𝑋 ∈ 𝑉))
11		eleq1 2854	. . . . . . . . . . . . . 14 ⊢ (𝑎 = 𝑌 → (𝑎 ∈ 𝑉 ↔ 𝑌 ∈ 𝑉))
12	11	eqcoms 2774	. . . . . . . . . . . . 13 ⊢ (𝑌 = 𝑎 → (𝑎 ∈ 𝑉 ↔ 𝑌 ∈ 𝑉))
13	10, 12	bi2anan9 650	. . . . . . . . . . . 12 ⊢ ((𝑋 = 𝑏 ∧ 𝑌 = 𝑎) → ((𝑏 ∈ 𝑉 ∧ 𝑎 ∈ 𝑉) ↔ (𝑋 ∈ 𝑉 ∧ 𝑌 ∈ 𝑉)))
14	13	biimpd 232	. . . . . . . . . . 11 ⊢ ((𝑋 = 𝑏 ∧ 𝑌 = 𝑎) → ((𝑏 ∈ 𝑉 ∧ 𝑎 ∈ 𝑉) → (𝑋 ∈ 𝑉 ∧ 𝑌 ∈ 𝑉)))
15	14	ancomsd 471	. . . . . . . . . 10 ⊢ ((𝑋 = 𝑏 ∧ 𝑌 = 𝑎) → ((𝑎 ∈ 𝑉 ∧ 𝑏 ∈ 𝑉) → (𝑋 ∈ 𝑉 ∧ 𝑌 ∈ 𝑉)))
16	8, 15	jaoi 871	. . . . . . . . 9 ⊢ (((𝑋 = 𝑎 ∧ 𝑌 = 𝑏) ∨ (𝑋 = 𝑏 ∧ 𝑌 = 𝑎)) → ((𝑎 ∈ 𝑉 ∧ 𝑏 ∈ 𝑉) → (𝑋 ∈ 𝑉 ∧ 𝑌 ∈ 𝑉)))
17	16	com12 33	. . . . . . . 8 ⊢ ((𝑎 ∈ 𝑉 ∧ 𝑏 ∈ 𝑉) → (((𝑋 = 𝑎 ∧ 𝑌 = 𝑏) ∨ (𝑋 = 𝑏 ∧ 𝑌 = 𝑎)) → (𝑋 ∈ 𝑉 ∧ 𝑌 ∈ 𝑉)))
18	17	adantl 487	. . . . . . 7 ⊢ (((𝑋 ∈ 𝑈 ∧ 𝑌 ∈ 𝑊) ∧ (𝑎 ∈ 𝑉 ∧ 𝑏 ∈ 𝑉)) → (((𝑋 = 𝑎 ∧ 𝑌 = 𝑏) ∨ (𝑋 = 𝑏 ∧ 𝑌 = 𝑎)) → (𝑋 ∈ 𝑉 ∧ 𝑌 ∈ 𝑉)))
19	2, 18	sylbid 243	. . . . . 6 ⊢ (((𝑋 ∈ 𝑈 ∧ 𝑌 ∈ 𝑊) ∧ (𝑎 ∈ 𝑉 ∧ 𝑏 ∈ 𝑉)) → ({𝑋, 𝑌} = {𝑎, 𝑏} → (𝑋 ∈ 𝑉 ∧ 𝑌 ∈ 𝑉)))
20	19	expcom 419	. . . . 5 ⊢ ((𝑎 ∈ 𝑉 ∧ 𝑏 ∈ 𝑉) → ((𝑋 ∈ 𝑈 ∧ 𝑌 ∈ 𝑊) → ({𝑋, 𝑌} = {𝑎, 𝑏} → (𝑋 ∈ 𝑉 ∧ 𝑌 ∈ 𝑉))))
21	20	com23 87	. . . 4 ⊢ ((𝑎 ∈ 𝑉 ∧ 𝑏 ∈ 𝑉) → ({𝑋, 𝑌} = {𝑎, 𝑏} → ((𝑋 ∈ 𝑈 ∧ 𝑌 ∈ 𝑊) → (𝑋 ∈ 𝑉 ∧ 𝑌 ∈ 𝑉))))
22	21	rexlimivv 3210	. . 3 ⊢ (∃𝑎 ∈ 𝑉 ∃𝑏 ∈ 𝑉 {𝑋, 𝑌} = {𝑎, 𝑏} → ((𝑋 ∈ 𝑈 ∧ 𝑌 ∈ 𝑊) → (𝑋 ∈ 𝑉 ∧ 𝑌 ∈ 𝑉)))
23	1, 22	syl 18	. 2 ⊢ ({𝑋, 𝑌} ∈ (Pairs‘𝑉) → ((𝑋 ∈ 𝑈 ∧ 𝑌 ∈ 𝑊) → (𝑋 ∈ 𝑉 ∧ 𝑌 ∈ 𝑉)))
24	23	imp 412	1 ⊢ (({𝑋, 𝑌} ∈ (Pairs‘𝑉) ∧ (𝑋 ∈ 𝑈 ∧ 𝑌 ∈ 𝑊)) → (𝑋 ∈ 𝑉 ∧ 𝑌 ∈ 𝑉))

This proof depends on syntax axioms:   → wi 4   ↔ wb 209   ∧ wa 401   ∨ wo 861   = wceq 1570   ∈ wcel 2146  ∃wrex 3092  {cpr 4596  ‘cfv 6543  Pairscspr 48267

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 48268

This theorem is used by:  prsssprel  48278  sprsymrelfolem2  48283