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Mirrors > Home > MPE Home > Th. List > tz6.26OLD | Structured version Visualization version GIF version |
Description: Obsolete proof of tz6.26 6348 as of 17-Nov-2024. (New usage is discouraged.) (Proof modification is discouraged.) (Contributed by Scott Fenton, 29-Jan-2011.) (Revised by Mario Carneiro, 26-Jun-2015.) |
Ref | Expression |
---|---|
tz6.26OLD | ⊢ (((𝑅 We 𝐴 ∧ 𝑅 Se 𝐴) ∧ (𝐵 ⊆ 𝐴 ∧ 𝐵 ≠ ∅)) → ∃𝑦 ∈ 𝐵 Pred(𝑅, 𝐵, 𝑦) = ∅) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | wereu2 5673 | . . 3 ⊢ (((𝑅 We 𝐴 ∧ 𝑅 Se 𝐴) ∧ (𝐵 ⊆ 𝐴 ∧ 𝐵 ≠ ∅)) → ∃!𝑦 ∈ 𝐵 ∀𝑥 ∈ 𝐵 ¬ 𝑥𝑅𝑦) | |
2 | reurex 3380 | . . 3 ⊢ (∃!𝑦 ∈ 𝐵 ∀𝑥 ∈ 𝐵 ¬ 𝑥𝑅𝑦 → ∃𝑦 ∈ 𝐵 ∀𝑥 ∈ 𝐵 ¬ 𝑥𝑅𝑦) | |
3 | 1, 2 | syl 17 | . 2 ⊢ (((𝑅 We 𝐴 ∧ 𝑅 Se 𝐴) ∧ (𝐵 ⊆ 𝐴 ∧ 𝐵 ≠ ∅)) → ∃𝑦 ∈ 𝐵 ∀𝑥 ∈ 𝐵 ¬ 𝑥𝑅𝑦) |
4 | rabeq0 4384 | . . . 4 ⊢ ({𝑥 ∈ 𝐵 ∣ 𝑥𝑅𝑦} = ∅ ↔ ∀𝑥 ∈ 𝐵 ¬ 𝑥𝑅𝑦) | |
5 | dfrab3 4309 | . . . . . 6 ⊢ {𝑥 ∈ 𝐵 ∣ 𝑥𝑅𝑦} = (𝐵 ∩ {𝑥 ∣ 𝑥𝑅𝑦}) | |
6 | vex 3478 | . . . . . . 7 ⊢ 𝑦 ∈ V | |
7 | 6 | dfpred2 6310 | . . . . . 6 ⊢ Pred(𝑅, 𝐵, 𝑦) = (𝐵 ∩ {𝑥 ∣ 𝑥𝑅𝑦}) |
8 | 5, 7 | eqtr4i 2763 | . . . . 5 ⊢ {𝑥 ∈ 𝐵 ∣ 𝑥𝑅𝑦} = Pred(𝑅, 𝐵, 𝑦) |
9 | 8 | eqeq1i 2737 | . . . 4 ⊢ ({𝑥 ∈ 𝐵 ∣ 𝑥𝑅𝑦} = ∅ ↔ Pred(𝑅, 𝐵, 𝑦) = ∅) |
10 | 4, 9 | bitr3i 276 | . . 3 ⊢ (∀𝑥 ∈ 𝐵 ¬ 𝑥𝑅𝑦 ↔ Pred(𝑅, 𝐵, 𝑦) = ∅) |
11 | 10 | rexbii 3094 | . 2 ⊢ (∃𝑦 ∈ 𝐵 ∀𝑥 ∈ 𝐵 ¬ 𝑥𝑅𝑦 ↔ ∃𝑦 ∈ 𝐵 Pred(𝑅, 𝐵, 𝑦) = ∅) |
12 | 3, 11 | sylib 217 | 1 ⊢ (((𝑅 We 𝐴 ∧ 𝑅 Se 𝐴) ∧ (𝐵 ⊆ 𝐴 ∧ 𝐵 ≠ ∅)) → ∃𝑦 ∈ 𝐵 Pred(𝑅, 𝐵, 𝑦) = ∅) |
Colors of variables: wff setvar class |
Syntax hints: ¬ wn 3 → wi 4 ∧ wa 396 = wceq 1541 {cab 2709 ≠ wne 2940 ∀wral 3061 ∃wrex 3070 ∃!wreu 3374 {crab 3432 ∩ cin 3947 ⊆ wss 3948 ∅c0 4322 class class class wbr 5148 Se wse 5629 We wwe 5630 Predcpred 6299 |
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-10 2137 ax-11 2154 ax-12 2171 ax-ext 2703 ax-sep 5299 ax-nul 5306 ax-pr 5427 |
This theorem depends on definitions: df-bi 206 df-an 397 df-or 846 df-3or 1088 df-3an 1089 df-tru 1544 df-fal 1554 df-ex 1782 df-nf 1786 df-sb 2068 df-mo 2534 df-eu 2563 df-clab 2710 df-cleq 2724 df-clel 2810 df-nfc 2885 df-ne 2941 df-ral 3062 df-rex 3071 df-rmo 3376 df-reu 3377 df-rab 3433 df-v 3476 df-dif 3951 df-un 3953 df-in 3955 df-ss 3965 df-nul 4323 df-if 4529 df-pw 4604 df-sn 4629 df-pr 4631 df-op 4635 df-br 5149 df-opab 5211 df-po 5588 df-so 5589 df-fr 5631 df-se 5632 df-we 5633 df-xp 5682 df-cnv 5684 df-dm 5686 df-rn 5687 df-res 5688 df-ima 5689 df-pred 6300 |
This theorem is referenced by: (None) |
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