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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 2184 | . . 3 ⊢ (𝑥 ∈ {𝑥 ∣ 𝜑} ↔ 𝜑) | |
| 2 | 1 | exbii 1619 | . 2 ⊢ (∃𝑥 𝑥 ∈ {𝑥 ∣ 𝜑} ↔ ∃𝑥𝜑) | 
| 3 | nfab1 2341 | . . 3 ⊢ Ⅎ𝑥{𝑥 ∣ 𝜑} | |
| 4 | 3 | n0rf 3463 | . 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 1506 ∈ wcel 2167 {cab 2182 ≠ wne 2367 ∅c0 3450 | 
| 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-ne 2368 df-v 2765 df-dif 3159 df-nul 3451 | 
| This theorem is referenced by: rabn0r 3477 | 
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