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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 2217 | . . 3 ⊢ (𝑥 ∈ {𝑥 ∣ 𝜑} ↔ 𝜑) | |
| 2 | 1 | exbii 1651 | . 2 ⊢ (∃𝑥 𝑥 ∈ {𝑥 ∣ 𝜑} ↔ ∃𝑥𝜑) |
| 3 | nfab1 2374 | . . 3 ⊢ Ⅎ𝑥{𝑥 ∣ 𝜑} | |
| 4 | 3 | n0rf 3504 | . 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 1538 ∈ wcel 2200 {cab 2215 ≠ wne 2400 ∅c0 3491 |
| 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 617 ax-in2 618 ax-io 714 ax-5 1493 ax-7 1494 ax-gen 1495 ax-ie1 1539 ax-ie2 1540 ax-8 1550 ax-10 1551 ax-11 1552 ax-i12 1553 ax-bndl 1555 ax-4 1556 ax-17 1572 ax-i9 1576 ax-ial 1580 ax-i5r 1581 ax-ext 2211 |
| This theorem depends on definitions: df-bi 117 df-tru 1398 df-fal 1401 df-nf 1507 df-sb 1809 df-clab 2216 df-cleq 2222 df-clel 2225 df-nfc 2361 df-ne 2401 df-v 2801 df-dif 3199 df-nul 3492 |
| This theorem is referenced by: rabn0r 3518 |
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