Theorem en2prd 7059

Description: Two proper unordered pairs are equinumerous. (Contributed by BTernaryTau, 23-Dec-2024.)

Hypotheses

Ref	Expression
en2prd.1	⊢ (𝜑 → 𝐴 ∈ 𝑉)
en2prd.2	⊢ (𝜑 → 𝐵 ∈ 𝑊)
en2prd.3	⊢ (𝜑 → 𝐶 ∈ 𝑋)
en2prd.4	⊢ (𝜑 → 𝐷 ∈ 𝑌)
en2prd.5	⊢ (𝜑 → 𝐴 ≠ 𝐵)
en2prd.6	⊢ (𝜑 → 𝐶 ≠ 𝐷)

Assertion

Ref	Expression
en2prd	⊢ (𝜑 → {𝐴, 𝐵} ≈ {𝐶, 𝐷})

Proof of Theorem en2prd

Dummy variable 𝑓 is distinct from all other variables.

Step	Hyp	Ref	Expression
1		en2prd.1	. . . . 5 ⊢ (𝜑 → 𝐴 ∈ 𝑉)
2		en2prd.3	. . . . 5 ⊢ (𝜑 → 𝐶 ∈ 𝑋)
3		opexg 4344	. . . . 5 ⊢ ((𝐴 ∈ 𝑉 ∧ 𝐶 ∈ 𝑋) → ⟨𝐴, 𝐶⟩ ∈ V)
4	1, 2, 3	syl2anc 411	. . . 4 ⊢ (𝜑 → ⟨𝐴, 𝐶⟩ ∈ V)
5		en2prd.2	. . . . 5 ⊢ (𝜑 → 𝐵 ∈ 𝑊)
6		en2prd.4	. . . . 5 ⊢ (𝜑 → 𝐷 ∈ 𝑌)
7		opexg 4344	. . . . 5 ⊢ ((𝐵 ∈ 𝑊 ∧ 𝐷 ∈ 𝑌) → ⟨𝐵, 𝐷⟩ ∈ V)
8	5, 6, 7	syl2anc 411	. . . 4 ⊢ (𝜑 → ⟨𝐵, 𝐷⟩ ∈ V)
9		prexg 4325	. . . 4 ⊢ ((⟨𝐴, 𝐶⟩ ∈ V ∧ ⟨𝐵, 𝐷⟩ ∈ V) → {⟨𝐴, 𝐶⟩, ⟨𝐵, 𝐷⟩} ∈ V)
10	4, 8, 9	syl2anc 411	. . 3 ⊢ (𝜑 → {⟨𝐴, 𝐶⟩, ⟨𝐵, 𝐷⟩} ∈ V)
11		en2prd.5	. . . 4 ⊢ (𝜑 → 𝐴 ≠ 𝐵)
12		en2prd.6	. . . 4 ⊢ (𝜑 → 𝐶 ≠ 𝐷)
13		f1oprg 5660	. . . . 5 ⊢ (((𝐴 ∈ 𝑉 ∧ 𝐶 ∈ 𝑋) ∧ (𝐵 ∈ 𝑊 ∧ 𝐷 ∈ 𝑌)) → ((𝐴 ≠ 𝐵 ∧ 𝐶 ≠ 𝐷) → {⟨𝐴, 𝐶⟩, ⟨𝐵, 𝐷⟩}:{𝐴, 𝐵}–1-1-onto→{𝐶, 𝐷}))
14	1, 2, 5, 6, 13	syl22anc 1275	. . . 4 ⊢ (𝜑 → ((𝐴 ≠ 𝐵 ∧ 𝐶 ≠ 𝐷) → {⟨𝐴, 𝐶⟩, ⟨𝐵, 𝐷⟩}:{𝐴, 𝐵}–1-1-onto→{𝐶, 𝐷}))
15	11, 12, 14	mp2and 433	. . 3 ⊢ (𝜑 → {⟨𝐴, 𝐶⟩, ⟨𝐵, 𝐷⟩}:{𝐴, 𝐵}–1-1-onto→{𝐶, 𝐷})
16		f1oeq1 5602	. . 3 ⊢ (𝑓 = {⟨𝐴, 𝐶⟩, ⟨𝐵, 𝐷⟩} → (𝑓:{𝐴, 𝐵}–1-1-onto→{𝐶, 𝐷} ↔ {⟨𝐴, 𝐶⟩, ⟨𝐵, 𝐷⟩}:{𝐴, 𝐵}–1-1-onto→{𝐶, 𝐷}))
17	10, 15, 16	elabd 2962	. 2 ⊢ (𝜑 → ∃𝑓 𝑓:{𝐴, 𝐵}–1-1-onto→{𝐶, 𝐷})
18		prexg 4325	. . . 4 ⊢ ((𝐴 ∈ 𝑉 ∧ 𝐵 ∈ 𝑊) → {𝐴, 𝐵} ∈ V)
19	1, 5, 18	syl2anc 411	. . 3 ⊢ (𝜑 → {𝐴, 𝐵} ∈ V)
20		prexg 4325	. . . 4 ⊢ ((𝐶 ∈ 𝑋 ∧ 𝐷 ∈ 𝑌) → {𝐶, 𝐷} ∈ V)
21	2, 6, 20	syl2anc 411	. . 3 ⊢ (𝜑 → {𝐶, 𝐷} ∈ V)
22		breng 6982	. . 3 ⊢ (({𝐴, 𝐵} ∈ V ∧ {𝐶, 𝐷} ∈ V) → ({𝐴, 𝐵} ≈ {𝐶, 𝐷} ↔ ∃𝑓 𝑓:{𝐴, 𝐵}–1-1-onto→{𝐶, 𝐷}))
23	19, 21, 22	syl2anc 411	. 2 ⊢ (𝜑 → ({𝐴, 𝐵} ≈ {𝐶, 𝐷} ↔ ∃𝑓 𝑓:{𝐴, 𝐵}–1-1-onto→{𝐶, 𝐷}))
24	17, 23	mpbird 167	1 ⊢ (𝜑 → {𝐴, 𝐵} ≈ {𝐶, 𝐷})

Syntax hints:   → wi 4   ∧ wa 104   ↔ wb 105  ∃wex 1541   ∈ wcel 2203   ≠ wne 2412  Vcvv 2813  {cpr 3690  ⟨cop 3692   class class class wbr 4109  –1-1-onto→wf1o 5351   ≈ cen 6973

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 106  ax-ia2 107  ax-ia3 108  ax-in1 619  ax-in2 620  ax-io 717  ax-5 1496  ax-7 1497  ax-gen 1498  ax-ie1 1542  ax-ie2 1543  ax-8 1553  ax-10 1554  ax-11 1555  ax-i12 1556  ax-bndl 1558  ax-4 1559  ax-17 1575  ax-i9 1579  ax-ial 1583  ax-i5r 1584  ax-14 2206  ax-ext 2214  ax-sep 4228  ax-pow 4287  ax-pr 4322

This theorem depends on definitions:  df-bi 117  df-3an 1007  df-tru 1401  df-fal 1404  df-nf 1510  df-sb 1812  df-eu 2083  df-mo 2084  df-clab 2219  df-cleq 2225  df-clel 2228  df-nfc 2373  df-ne 2413  df-ral 2525  df-rex 2526  df-v 2815  df-dif 3213  df-un 3215  df-in 3217  df-ss 3224  df-nul 3509  df-pw 3671  df-sn 3695  df-pr 3696  df-op 3698  df-br 4110  df-opab 4172  df-id 4414  df-xp 4755  df-rel 4756  df-cnv 4757  df-co 4758  df-dm 4759  df-rn 4760  df-fun 5354  df-fn 5355  df-f 5356  df-f1 5357  df-fo 5358  df-f1o 5359  df-en 6976

This theorem is referenced by:  rex2dom  7063