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Mirrors > Home > MPE Home > Th. List > domeng | Structured version Visualization version GIF version |
Description: Dominance in terms of equinumerosity, with the sethood requirement expressed as an antecedent. Example 1 of [Enderton] p. 146. (Contributed by NM, 24-Apr-2004.) |
Ref | Expression |
---|---|
domeng | ⊢ (𝐵 ∈ 𝐶 → (𝐴 ≼ 𝐵 ↔ ∃𝑥(𝐴 ≈ 𝑥 ∧ 𝑥 ⊆ 𝐵))) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | breq2 5151 | . 2 ⊢ (𝑦 = 𝐵 → (𝐴 ≼ 𝑦 ↔ 𝐴 ≼ 𝐵)) | |
2 | sseq2 4007 | . . . 4 ⊢ (𝑦 = 𝐵 → (𝑥 ⊆ 𝑦 ↔ 𝑥 ⊆ 𝐵)) | |
3 | 2 | anbi2d 629 | . . 3 ⊢ (𝑦 = 𝐵 → ((𝐴 ≈ 𝑥 ∧ 𝑥 ⊆ 𝑦) ↔ (𝐴 ≈ 𝑥 ∧ 𝑥 ⊆ 𝐵))) |
4 | 3 | exbidv 1924 | . 2 ⊢ (𝑦 = 𝐵 → (∃𝑥(𝐴 ≈ 𝑥 ∧ 𝑥 ⊆ 𝑦) ↔ ∃𝑥(𝐴 ≈ 𝑥 ∧ 𝑥 ⊆ 𝐵))) |
5 | vex 3478 | . . 3 ⊢ 𝑦 ∈ V | |
6 | 5 | domen 8953 | . 2 ⊢ (𝐴 ≼ 𝑦 ↔ ∃𝑥(𝐴 ≈ 𝑥 ∧ 𝑥 ⊆ 𝑦)) |
7 | 1, 4, 6 | vtoclbg 3559 | 1 ⊢ (𝐵 ∈ 𝐶 → (𝐴 ≼ 𝐵 ↔ ∃𝑥(𝐴 ≈ 𝑥 ∧ 𝑥 ⊆ 𝐵))) |
Colors of variables: wff setvar class |
Syntax hints: → wi 4 ↔ wb 205 ∧ wa 396 = wceq 1541 ∃wex 1781 ∈ wcel 2106 ⊆ wss 3947 class class class wbr 5147 ≈ cen 8932 ≼ cdom 8933 |
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 1913 ax-6 1971 ax-7 2011 ax-8 2108 ax-9 2116 ax-11 2154 ax-ext 2703 ax-sep 5298 ax-nul 5305 ax-pr 5426 ax-un 7721 |
This theorem depends on definitions: df-bi 206 df-an 397 df-or 846 df-3an 1089 df-tru 1544 df-fal 1554 df-ex 1782 df-sb 2068 df-clab 2710 df-cleq 2724 df-clel 2810 df-ral 3062 df-rex 3071 df-rab 3433 df-v 3476 df-dif 3950 df-un 3952 df-in 3954 df-ss 3964 df-nul 4322 df-if 4528 df-sn 4628 df-pr 4630 df-op 4634 df-uni 4908 df-br 5148 df-opab 5210 df-xp 5681 df-rel 5682 df-cnv 5683 df-dm 5685 df-rn 5686 df-fn 6543 df-f 6544 df-f1 6545 df-fo 6546 df-f1o 6547 df-en 8936 df-dom 8937 |
This theorem is referenced by: undomOLD 9056 mapdom1 9138 mapdom2 9144 domfi 9188 isfinite2 9297 unxpwdom 9580 djuinf 10179 domfin4 10302 pwfseq 10655 grudomon 10808 ufldom 23457 erdsze2lem1 34182 |
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