| Intuitionistic Logic Explorer |
< Previous
Next >
Nearby theorems |
||
| 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 3516 | . 2 ⊢ (∃𝑥(𝑥 ∈ 𝐴 ∧ 𝜑) → {𝑥 ∣ (𝑥 ∈ 𝐴 ∧ 𝜑)} ≠ ∅) | |
| 2 | df-rex 2514 | . 2 ⊢ (∃𝑥 ∈ 𝐴 𝜑 ↔ ∃𝑥(𝑥 ∈ 𝐴 ∧ 𝜑)) | |
| 3 | df-rab 2517 | . . 3 ⊢ {𝑥 ∈ 𝐴 ∣ 𝜑} = {𝑥 ∣ (𝑥 ∈ 𝐴 ∧ 𝜑)} | |
| 4 | 3 | neeq1i 2415 | . 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 1538 ∈ wcel 2200 {cab 2215 ≠ wne 2400 ∃wrex 2509 {crab 2512 ∅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-rex 2514 df-rab 2517 df-v 2801 df-dif 3199 df-nul 3492 |
| This theorem is referenced by: sgmnncl 15647 |
| Copyright terms: Public domain | W3C validator |