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Mirrors > Home > MPE Home > Th. List > endisj | Structured version Visualization version GIF version |
Description: Any two sets are equinumerous to two disjoint sets. Exercise 4.39 of [Mendelson] p. 255. (Contributed by NM, 16-Apr-2004.) |
Ref | Expression |
---|---|
endisj.1 | ⊢ 𝐴 ∈ V |
endisj.2 | ⊢ 𝐵 ∈ V |
Ref | Expression |
---|---|
endisj | ⊢ ∃𝑥∃𝑦((𝑥 ≈ 𝐴 ∧ 𝑦 ≈ 𝐵) ∧ (𝑥 ∩ 𝑦) = ∅) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | endisj.1 | . . . 4 ⊢ 𝐴 ∈ V | |
2 | 0ex 5301 | . . . 4 ⊢ ∅ ∈ V | |
3 | 1, 2 | xpsnen 9073 | . . 3 ⊢ (𝐴 × {∅}) ≈ 𝐴 |
4 | endisj.2 | . . . 4 ⊢ 𝐵 ∈ V | |
5 | 1oex 8490 | . . . 4 ⊢ 1o ∈ V | |
6 | 4, 5 | xpsnen 9073 | . . 3 ⊢ (𝐵 × {1o}) ≈ 𝐵 |
7 | 3, 6 | pm3.2i 470 | . 2 ⊢ ((𝐴 × {∅}) ≈ 𝐴 ∧ (𝐵 × {1o}) ≈ 𝐵) |
8 | xp01disj 8505 | . 2 ⊢ ((𝐴 × {∅}) ∩ (𝐵 × {1o})) = ∅ | |
9 | p0ex 5378 | . . . 4 ⊢ {∅} ∈ V | |
10 | 1, 9 | xpex 7749 | . . 3 ⊢ (𝐴 × {∅}) ∈ V |
11 | snex 5427 | . . . 4 ⊢ {1o} ∈ V | |
12 | 4, 11 | xpex 7749 | . . 3 ⊢ (𝐵 × {1o}) ∈ V |
13 | breq1 5145 | . . . . 5 ⊢ (𝑥 = (𝐴 × {∅}) → (𝑥 ≈ 𝐴 ↔ (𝐴 × {∅}) ≈ 𝐴)) | |
14 | breq1 5145 | . . . . 5 ⊢ (𝑦 = (𝐵 × {1o}) → (𝑦 ≈ 𝐵 ↔ (𝐵 × {1o}) ≈ 𝐵)) | |
15 | 13, 14 | bi2anan9 637 | . . . 4 ⊢ ((𝑥 = (𝐴 × {∅}) ∧ 𝑦 = (𝐵 × {1o})) → ((𝑥 ≈ 𝐴 ∧ 𝑦 ≈ 𝐵) ↔ ((𝐴 × {∅}) ≈ 𝐴 ∧ (𝐵 × {1o}) ≈ 𝐵))) |
16 | ineq12 4203 | . . . . 5 ⊢ ((𝑥 = (𝐴 × {∅}) ∧ 𝑦 = (𝐵 × {1o})) → (𝑥 ∩ 𝑦) = ((𝐴 × {∅}) ∩ (𝐵 × {1o}))) | |
17 | 16 | eqeq1d 2730 | . . . 4 ⊢ ((𝑥 = (𝐴 × {∅}) ∧ 𝑦 = (𝐵 × {1o})) → ((𝑥 ∩ 𝑦) = ∅ ↔ ((𝐴 × {∅}) ∩ (𝐵 × {1o})) = ∅)) |
18 | 15, 17 | anbi12d 631 | . . 3 ⊢ ((𝑥 = (𝐴 × {∅}) ∧ 𝑦 = (𝐵 × {1o})) → (((𝑥 ≈ 𝐴 ∧ 𝑦 ≈ 𝐵) ∧ (𝑥 ∩ 𝑦) = ∅) ↔ (((𝐴 × {∅}) ≈ 𝐴 ∧ (𝐵 × {1o}) ≈ 𝐵) ∧ ((𝐴 × {∅}) ∩ (𝐵 × {1o})) = ∅))) |
19 | 10, 12, 18 | spc2ev 3593 | . 2 ⊢ ((((𝐴 × {∅}) ≈ 𝐴 ∧ (𝐵 × {1o}) ≈ 𝐵) ∧ ((𝐴 × {∅}) ∩ (𝐵 × {1o})) = ∅) → ∃𝑥∃𝑦((𝑥 ≈ 𝐴 ∧ 𝑦 ≈ 𝐵) ∧ (𝑥 ∩ 𝑦) = ∅)) |
20 | 7, 8, 19 | mp2an 691 | 1 ⊢ ∃𝑥∃𝑦((𝑥 ≈ 𝐴 ∧ 𝑦 ≈ 𝐵) ∧ (𝑥 ∩ 𝑦) = ∅) |
Colors of variables: wff setvar class |
Syntax hints: ∧ wa 395 = wceq 1534 ∃wex 1774 ∈ wcel 2099 Vcvv 3470 ∩ cin 3944 ∅c0 4318 {csn 4624 class class class wbr 5142 × cxp 5670 1oc1o 8473 ≈ cen 8954 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1790 ax-4 1804 ax-5 1906 ax-6 1964 ax-7 2004 ax-8 2101 ax-9 2109 ax-10 2130 ax-11 2147 ax-12 2167 ax-ext 2699 ax-sep 5293 ax-nul 5300 ax-pow 5359 ax-pr 5423 ax-un 7734 |
This theorem depends on definitions: df-bi 206 df-an 396 df-or 847 df-3an 1087 df-tru 1537 df-fal 1547 df-ex 1775 df-nf 1779 df-sb 2061 df-mo 2530 df-eu 2559 df-clab 2706 df-cleq 2720 df-clel 2806 df-nfc 2881 df-ne 2937 df-ral 3058 df-rex 3067 df-rab 3429 df-v 3472 df-dif 3948 df-un 3950 df-in 3952 df-ss 3962 df-nul 4319 df-if 4525 df-pw 4600 df-sn 4625 df-pr 4627 df-op 4631 df-uni 4904 df-int 4945 df-br 5143 df-opab 5205 df-mpt 5226 df-id 5570 df-xp 5678 df-rel 5679 df-cnv 5680 df-co 5681 df-dm 5682 df-rn 5683 df-suc 6369 df-fun 6544 df-fn 6545 df-f 6546 df-f1 6547 df-fo 6548 df-f1o 6549 df-1o 8480 df-en 8958 |
This theorem is referenced by: (None) |
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