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| Mirrors > Home > ILE Home > Th. List > abn0r | GIF version | ||
| Description: Nonempty class abstraction. (Contributed by Jim Kingdon, 1-Aug-2018.) |
| Ref | Expression |
|---|---|
| abn0r | ⊢ (∃𝑥𝜑 → {𝑥 ∣ 𝜑} ≠ ∅) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | abid 2219 | . . 3 ⊢ (𝑥 ∈ {𝑥 ∣ 𝜑} ↔ 𝜑) | |
| 2 | 1 | exbii 1654 | . 2 ⊢ (∃𝑥 𝑥 ∈ {𝑥 ∣ 𝜑} ↔ ∃𝑥𝜑) |
| 3 | nfab1 2377 | . . 3 ⊢ Ⅎ𝑥{𝑥 ∣ 𝜑} | |
| 4 | 3 | n0rf 3509 | . 2 ⊢ (∃𝑥 𝑥 ∈ {𝑥 ∣ 𝜑} → {𝑥 ∣ 𝜑} ≠ ∅) |
| 5 | 2, 4 | sylbir 135 | 1 ⊢ (∃𝑥𝜑 → {𝑥 ∣ 𝜑} ≠ ∅) |
| Colors of variables: wff set class |
| Syntax hints: → wi 4 ∃wex 1541 ∈ wcel 2202 {cab 2217 ≠ wne 2403 ∅c0 3496 |
| 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 619 ax-in2 620 ax-io 717 ax-5 1496 ax-7 1497 ax-gen 1498 ax-ie1 1542 ax-ie2 1543 ax-8 1553 ax-10 1554 ax-11 1555 ax-i12 1556 ax-bndl 1558 ax-4 1559 ax-17 1575 ax-i9 1579 ax-ial 1583 ax-i5r 1584 ax-ext 2213 |
| This theorem depends on definitions: df-bi 117 df-tru 1401 df-fal 1404 df-nf 1510 df-sb 1811 df-clab 2218 df-cleq 2224 df-clel 2227 df-nfc 2364 df-ne 2404 df-v 2805 df-dif 3203 df-nul 3497 |
| This theorem is referenced by: rabn0r 3523 |
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