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| Mirrors > Home > ILE Home > Th. List > rabeq0 | GIF version | ||
| Description: Condition for a restricted class abstraction to be empty. (Contributed by Jeff Madsen, 7-Jun-2010.) |
| Ref | Expression |
|---|---|
| rabeq0 | ⊢ ({𝑥 ∈ 𝐴 ∣ 𝜑} = ∅ ↔ ∀𝑥 ∈ 𝐴 ¬ 𝜑) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | imnan 691 | . . 3 ⊢ ((𝑥 ∈ 𝐴 → ¬ 𝜑) ↔ ¬ (𝑥 ∈ 𝐴 ∧ 𝜑)) | |
| 2 | 1 | albii 1484 | . 2 ⊢ (∀𝑥(𝑥 ∈ 𝐴 → ¬ 𝜑) ↔ ∀𝑥 ¬ (𝑥 ∈ 𝐴 ∧ 𝜑)) |
| 3 | df-ral 2480 | . 2 ⊢ (∀𝑥 ∈ 𝐴 ¬ 𝜑 ↔ ∀𝑥(𝑥 ∈ 𝐴 → ¬ 𝜑)) | |
| 4 | sbn 1971 | . . . 4 ⊢ ([𝑦 / 𝑥] ¬ (𝑥 ∈ 𝐴 ∧ 𝜑) ↔ ¬ [𝑦 / 𝑥](𝑥 ∈ 𝐴 ∧ 𝜑)) | |
| 5 | 4 | albii 1484 | . . 3 ⊢ (∀𝑦[𝑦 / 𝑥] ¬ (𝑥 ∈ 𝐴 ∧ 𝜑) ↔ ∀𝑦 ¬ [𝑦 / 𝑥](𝑥 ∈ 𝐴 ∧ 𝜑)) |
| 6 | nfv 1542 | . . . 4 ⊢ Ⅎ𝑦 ¬ (𝑥 ∈ 𝐴 ∧ 𝜑) | |
| 7 | 6 | sb8 1870 | . . 3 ⊢ (∀𝑥 ¬ (𝑥 ∈ 𝐴 ∧ 𝜑) ↔ ∀𝑦[𝑦 / 𝑥] ¬ (𝑥 ∈ 𝐴 ∧ 𝜑)) |
| 8 | eq0 3470 | . . . 4 ⊢ ({𝑥 ∈ 𝐴 ∣ 𝜑} = ∅ ↔ ∀𝑦 ¬ 𝑦 ∈ {𝑥 ∈ 𝐴 ∣ 𝜑}) | |
| 9 | df-rab 2484 | . . . . . . . 8 ⊢ {𝑥 ∈ 𝐴 ∣ 𝜑} = {𝑥 ∣ (𝑥 ∈ 𝐴 ∧ 𝜑)} | |
| 10 | 9 | eleq2i 2263 | . . . . . . 7 ⊢ (𝑦 ∈ {𝑥 ∈ 𝐴 ∣ 𝜑} ↔ 𝑦 ∈ {𝑥 ∣ (𝑥 ∈ 𝐴 ∧ 𝜑)}) |
| 11 | df-clab 2183 | . . . . . . 7 ⊢ (𝑦 ∈ {𝑥 ∣ (𝑥 ∈ 𝐴 ∧ 𝜑)} ↔ [𝑦 / 𝑥](𝑥 ∈ 𝐴 ∧ 𝜑)) | |
| 12 | 10, 11 | bitri 184 | . . . . . 6 ⊢ (𝑦 ∈ {𝑥 ∈ 𝐴 ∣ 𝜑} ↔ [𝑦 / 𝑥](𝑥 ∈ 𝐴 ∧ 𝜑)) |
| 13 | 12 | notbii 669 | . . . . 5 ⊢ (¬ 𝑦 ∈ {𝑥 ∈ 𝐴 ∣ 𝜑} ↔ ¬ [𝑦 / 𝑥](𝑥 ∈ 𝐴 ∧ 𝜑)) |
| 14 | 13 | albii 1484 | . . . 4 ⊢ (∀𝑦 ¬ 𝑦 ∈ {𝑥 ∈ 𝐴 ∣ 𝜑} ↔ ∀𝑦 ¬ [𝑦 / 𝑥](𝑥 ∈ 𝐴 ∧ 𝜑)) |
| 15 | 8, 14 | bitri 184 | . . 3 ⊢ ({𝑥 ∈ 𝐴 ∣ 𝜑} = ∅ ↔ ∀𝑦 ¬ [𝑦 / 𝑥](𝑥 ∈ 𝐴 ∧ 𝜑)) |
| 16 | 5, 7, 15 | 3bitr4ri 213 | . 2 ⊢ ({𝑥 ∈ 𝐴 ∣ 𝜑} = ∅ ↔ ∀𝑥 ¬ (𝑥 ∈ 𝐴 ∧ 𝜑)) |
| 17 | 2, 3, 16 | 3bitr4ri 213 | 1 ⊢ ({𝑥 ∈ 𝐴 ∣ 𝜑} = ∅ ↔ ∀𝑥 ∈ 𝐴 ¬ 𝜑) |
| Colors of variables: wff set class |
| Syntax hints: ¬ wn 3 → wi 4 ∧ wa 104 ↔ wb 105 ∀wal 1362 = wceq 1364 [wsb 1776 ∈ wcel 2167 {cab 2182 ∀wral 2475 {crab 2479 ∅c0 3451 |
| 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 615 ax-in2 616 ax-io 710 ax-5 1461 ax-7 1462 ax-gen 1463 ax-ie1 1507 ax-ie2 1508 ax-8 1518 ax-10 1519 ax-11 1520 ax-i12 1521 ax-bndl 1523 ax-4 1524 ax-17 1540 ax-i9 1544 ax-ial 1548 ax-i5r 1549 ax-ext 2178 |
| This theorem depends on definitions: df-bi 117 df-tru 1367 df-fal 1370 df-nf 1475 df-sb 1777 df-clab 2183 df-cleq 2189 df-clel 2192 df-nfc 2328 df-ral 2480 df-rab 2484 df-v 2765 df-dif 3159 df-nul 3452 |
| This theorem is referenced by: rabnc 3484 rabrsndc 3691 exmidsssnc 4237 ssfilem 6945 diffitest 6957 ssfirab 7006 ctssexmid 7225 exmidonfinlem 7272 iooidg 10001 icc0r 10018 fznlem 10133 ioo0 10366 ico0 10368 ioc0 10369 phiprmpw 12415 hashgcdeq 12433 unennn 12639 znnen 12640 fczpsrbag 14301 lgsquadlem2 15403 |
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