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| Mirrors > Home > ILE Home > Th. List > rabn0r | GIF version | ||
| Description: Nonempty restricted class abstraction. (Contributed by Jim Kingdon, 1-Aug-2018.) |
| Ref | Expression |
|---|---|
| rabn0r | ⊢ (∃𝑥 ∈ 𝐴 𝜑 → {𝑥 ∈ 𝐴 ∣ 𝜑} ≠ ∅) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | abn0r 3487 | . 2 ⊢ (∃𝑥(𝑥 ∈ 𝐴 ∧ 𝜑) → {𝑥 ∣ (𝑥 ∈ 𝐴 ∧ 𝜑)} ≠ ∅) | |
| 2 | df-rex 2491 | . 2 ⊢ (∃𝑥 ∈ 𝐴 𝜑 ↔ ∃𝑥(𝑥 ∈ 𝐴 ∧ 𝜑)) | |
| 3 | df-rab 2494 | . . 3 ⊢ {𝑥 ∈ 𝐴 ∣ 𝜑} = {𝑥 ∣ (𝑥 ∈ 𝐴 ∧ 𝜑)} | |
| 4 | 3 | neeq1i 2392 | . 2 ⊢ ({𝑥 ∈ 𝐴 ∣ 𝜑} ≠ ∅ ↔ {𝑥 ∣ (𝑥 ∈ 𝐴 ∧ 𝜑)} ≠ ∅) |
| 5 | 1, 2, 4 | 3imtr4i 201 | 1 ⊢ (∃𝑥 ∈ 𝐴 𝜑 → {𝑥 ∈ 𝐴 ∣ 𝜑} ≠ ∅) |
| Colors of variables: wff set class |
| Syntax hints: → wi 4 ∧ wa 104 ∃wex 1516 ∈ wcel 2177 {cab 2192 ≠ wne 2377 ∃wrex 2486 {crab 2489 ∅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-rex 2491 df-rab 2494 df-v 2775 df-dif 3170 df-nul 3463 |
| This theorem is referenced by: sgmnncl 15510 |
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