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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 2028 | . . 3 ⊢ (𝑥 ∈ {𝑥 ∣ 𝜑} ↔ 𝜑) | |
2 | 1 | exbii 1496 | . 2 ⊢ (∃𝑥 𝑥 ∈ {𝑥 ∣ 𝜑} ↔ ∃𝑥𝜑) |
3 | nfab1 2180 | . . 3 ⊢ Ⅎ𝑥{𝑥 ∣ 𝜑} | |
4 | 3 | n0rf 3233 | . 2 ⊢ (∃𝑥 𝑥 ∈ {𝑥 ∣ 𝜑} → {𝑥 ∣ 𝜑} ≠ ∅) |
5 | 2, 4 | sylbir 125 | 1 ⊢ (∃𝑥𝜑 → {𝑥 ∣ 𝜑} ≠ ∅) |
Colors of variables: wff set class |
Syntax hints: → wi 4 ∃wex 1381 ∈ wcel 1393 {cab 2026 ≠ wne 2204 ∅c0 3224 |
This theorem was proved from axioms: ax-1 5 ax-2 6 ax-mp 7 ax-ia1 99 ax-ia2 100 ax-ia3 101 ax-in1 544 ax-in2 545 ax-io 630 ax-5 1336 ax-7 1337 ax-gen 1338 ax-ie1 1382 ax-ie2 1383 ax-8 1395 ax-10 1396 ax-11 1397 ax-i12 1398 ax-bndl 1399 ax-4 1400 ax-17 1419 ax-i9 1423 ax-ial 1427 ax-i5r 1428 ax-ext 2022 |
This theorem depends on definitions: df-bi 110 df-tru 1246 df-fal 1249 df-nf 1350 df-sb 1646 df-clab 2027 df-cleq 2033 df-clel 2036 df-nfc 2167 df-ne 2206 df-v 2559 df-dif 2920 df-nul 3225 |
This theorem is referenced by: rabn0r 3244 |
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