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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 2194 | . . 3 ⊢ (𝑥 ∈ {𝑥 ∣ 𝜑} ↔ 𝜑) | |
| 2 | 1 | exbii 1629 | . 2 ⊢ (∃𝑥 𝑥 ∈ {𝑥 ∣ 𝜑} ↔ ∃𝑥𝜑) |
| 3 | nfab1 2351 | . . 3 ⊢ Ⅎ𝑥{𝑥 ∣ 𝜑} | |
| 4 | 3 | n0rf 3475 | . 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 1516 ∈ wcel 2177 {cab 2192 ≠ wne 2377 ∅c0 3462 |
| 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 711 ax-5 1471 ax-7 1472 ax-gen 1473 ax-ie1 1517 ax-ie2 1518 ax-8 1528 ax-10 1529 ax-11 1530 ax-i12 1531 ax-bndl 1533 ax-4 1534 ax-17 1550 ax-i9 1554 ax-ial 1558 ax-i5r 1559 ax-ext 2188 |
| This theorem depends on definitions: df-bi 117 df-tru 1376 df-fal 1379 df-nf 1485 df-sb 1787 df-clab 2193 df-cleq 2199 df-clel 2202 df-nfc 2338 df-ne 2378 df-v 2775 df-dif 3170 df-nul 3463 |
| This theorem is referenced by: rabn0r 3489 |
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