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Mirrors > Home > MPE Home > Th. List > Mathboxes > pr2cv | Structured version Visualization version GIF version |
Description: If an unordered pair is equinumerous to ordinal two, then both parts are sets. (Contributed by RP, 8-Oct-2023.) |
Ref | Expression |
---|---|
pr2cv | ⊢ ({𝐴, 𝐵} ≈ 2o → (𝐴 ∈ V ∧ 𝐵 ∈ V)) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | en2 8738 | . 2 ⊢ ({𝐴, 𝐵} ≈ 2o → ∃𝑥∃𝑦{𝐴, 𝐵} = {𝑥, 𝑦}) | |
2 | breq1 5033 | . . . 4 ⊢ ({𝐴, 𝐵} = {𝑥, 𝑦} → ({𝐴, 𝐵} ≈ 2o ↔ {𝑥, 𝑦} ≈ 2o)) | |
3 | vex 3444 | . . . . . . 7 ⊢ 𝑥 ∈ V | |
4 | vex 3444 | . . . . . . 7 ⊢ 𝑦 ∈ V | |
5 | pr2ne 9416 | . . . . . . . . 9 ⊢ ((𝑥 ∈ V ∧ 𝑦 ∈ V) → ({𝑥, 𝑦} ≈ 2o ↔ 𝑥 ≠ 𝑦)) | |
6 | 5 | el2v 3448 | . . . . . . . 8 ⊢ ({𝑥, 𝑦} ≈ 2o ↔ 𝑥 ≠ 𝑦) |
7 | 6 | biimpi 219 | . . . . . . 7 ⊢ ({𝑥, 𝑦} ≈ 2o → 𝑥 ≠ 𝑦) |
8 | preq12nebg 4753 | . . . . . . . 8 ⊢ ((𝑥 ∈ V ∧ 𝑦 ∈ V ∧ 𝑥 ≠ 𝑦) → ({𝑥, 𝑦} = {𝐴, 𝐵} ↔ ((𝑥 = 𝐴 ∧ 𝑦 = 𝐵) ∨ (𝑥 = 𝐵 ∧ 𝑦 = 𝐴)))) | |
9 | eqvisset 3458 | . . . . . . . . . 10 ⊢ (𝑥 = 𝐴 → 𝐴 ∈ V) | |
10 | eqvisset 3458 | . . . . . . . . . 10 ⊢ (𝑦 = 𝐵 → 𝐵 ∈ V) | |
11 | 9, 10 | anim12i 615 | . . . . . . . . 9 ⊢ ((𝑥 = 𝐴 ∧ 𝑦 = 𝐵) → (𝐴 ∈ V ∧ 𝐵 ∈ V)) |
12 | eqvisset 3458 | . . . . . . . . . 10 ⊢ (𝑥 = 𝐵 → 𝐵 ∈ V) | |
13 | eqvisset 3458 | . . . . . . . . . 10 ⊢ (𝑦 = 𝐴 → 𝐴 ∈ V) | |
14 | 12, 13 | anim12ci 616 | . . . . . . . . 9 ⊢ ((𝑥 = 𝐵 ∧ 𝑦 = 𝐴) → (𝐴 ∈ V ∧ 𝐵 ∈ V)) |
15 | 11, 14 | jaoi 854 | . . . . . . . 8 ⊢ (((𝑥 = 𝐴 ∧ 𝑦 = 𝐵) ∨ (𝑥 = 𝐵 ∧ 𝑦 = 𝐴)) → (𝐴 ∈ V ∧ 𝐵 ∈ V)) |
16 | 8, 15 | syl6bi 256 | . . . . . . 7 ⊢ ((𝑥 ∈ V ∧ 𝑦 ∈ V ∧ 𝑥 ≠ 𝑦) → ({𝑥, 𝑦} = {𝐴, 𝐵} → (𝐴 ∈ V ∧ 𝐵 ∈ V))) |
17 | 3, 4, 7, 16 | mp3an12i 1462 | . . . . . 6 ⊢ ({𝑥, 𝑦} ≈ 2o → ({𝑥, 𝑦} = {𝐴, 𝐵} → (𝐴 ∈ V ∧ 𝐵 ∈ V))) |
18 | 17 | com12 32 | . . . . 5 ⊢ ({𝑥, 𝑦} = {𝐴, 𝐵} → ({𝑥, 𝑦} ≈ 2o → (𝐴 ∈ V ∧ 𝐵 ∈ V))) |
19 | 18 | eqcoms 2806 | . . . 4 ⊢ ({𝐴, 𝐵} = {𝑥, 𝑦} → ({𝑥, 𝑦} ≈ 2o → (𝐴 ∈ V ∧ 𝐵 ∈ V))) |
20 | 2, 19 | sylbid 243 | . . 3 ⊢ ({𝐴, 𝐵} = {𝑥, 𝑦} → ({𝐴, 𝐵} ≈ 2o → (𝐴 ∈ V ∧ 𝐵 ∈ V))) |
21 | 20 | exlimivv 1933 | . 2 ⊢ (∃𝑥∃𝑦{𝐴, 𝐵} = {𝑥, 𝑦} → ({𝐴, 𝐵} ≈ 2o → (𝐴 ∈ V ∧ 𝐵 ∈ V))) |
22 | 1, 21 | mpcom 38 | 1 ⊢ ({𝐴, 𝐵} ≈ 2o → (𝐴 ∈ V ∧ 𝐵 ∈ V)) |
Colors of variables: wff setvar class |
Syntax hints: → wi 4 ↔ wb 209 ∧ wa 399 ∨ wo 844 ∧ w3a 1084 = wceq 1538 ∃wex 1781 ∈ wcel 2111 ≠ wne 2987 Vcvv 3441 {cpr 4527 class class class wbr 5030 2oc2o 8079 ≈ cen 8489 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1797 ax-4 1811 ax-5 1911 ax-6 1970 ax-7 2015 ax-8 2113 ax-9 2121 ax-10 2142 ax-11 2158 ax-12 2175 ax-ext 2770 ax-sep 5167 ax-nul 5174 ax-pow 5231 ax-pr 5295 ax-un 7441 |
This theorem depends on definitions: df-bi 210 df-an 400 df-or 845 df-3or 1085 df-3an 1086 df-tru 1541 df-ex 1782 df-nf 1786 df-sb 2070 df-mo 2598 df-eu 2629 df-clab 2777 df-cleq 2791 df-clel 2870 df-nfc 2938 df-ne 2988 df-ral 3111 df-rex 3112 df-reu 3113 df-rab 3115 df-v 3443 df-sbc 3721 df-dif 3884 df-un 3886 df-in 3888 df-ss 3898 df-pss 3900 df-nul 4244 df-if 4426 df-pw 4499 df-sn 4526 df-pr 4528 df-tp 4530 df-op 4532 df-uni 4801 df-br 5031 df-opab 5093 df-tr 5137 df-id 5425 df-eprel 5430 df-po 5438 df-so 5439 df-fr 5478 df-we 5480 df-xp 5525 df-rel 5526 df-cnv 5527 df-co 5528 df-dm 5529 df-rn 5530 df-res 5531 df-ima 5532 df-ord 6162 df-on 6163 df-lim 6164 df-suc 6165 df-iota 6283 df-fun 6326 df-fn 6327 df-f 6328 df-f1 6329 df-fo 6330 df-f1o 6331 df-fv 6332 df-om 7561 df-1o 8085 df-2o 8086 df-er 8272 df-en 8493 df-dom 8494 df-sdom 8495 df-fin 8496 |
This theorem is referenced by: pr2el1 40248 pr2cv1 40249 pr2el2 40250 pr2cv2 40251 pren2 40252 |
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