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| Mirrors > Home > ILE Home > Th. List > elabf | GIF version | ||
| Description: Membership in a class abstraction, using implicit substitution. (Contributed by NM, 1-Aug-1994.) (Revised by Mario Carneiro, 12-Oct-2016.) |
| Ref | Expression |
|---|---|
| elabf.1 | ⊢ Ⅎ𝑥𝜓 |
| elabf.2 | ⊢ 𝐴 ∈ V |
| elabf.3 | ⊢ (𝑥 = 𝐴 → (𝜑 ↔ 𝜓)) |
| Ref | Expression |
|---|---|
| elabf | ⊢ (𝐴 ∈ {𝑥 ∣ 𝜑} ↔ 𝜓) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | elabf.2 | . 2 ⊢ 𝐴 ∈ V | |
| 2 | nfcv 2349 | . . 3 ⊢ Ⅎ𝑥𝐴 | |
| 3 | elabf.1 | . . 3 ⊢ Ⅎ𝑥𝜓 | |
| 4 | elabf.3 | . . 3 ⊢ (𝑥 = 𝐴 → (𝜑 ↔ 𝜓)) | |
| 5 | 2, 3, 4 | elabgf 2916 | . 2 ⊢ (𝐴 ∈ V → (𝐴 ∈ {𝑥 ∣ 𝜑} ↔ 𝜓)) |
| 6 | 1, 5 | ax-mp 5 | 1 ⊢ (𝐴 ∈ {𝑥 ∣ 𝜑} ↔ 𝜓) |
| Colors of variables: wff set class |
| Syntax hints: → wi 4 ↔ wb 105 = wceq 1373 Ⅎwnf 1484 ∈ wcel 2177 {cab 2192 Vcvv 2773 |
| 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-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-nf 1485 df-sb 1787 df-clab 2193 df-cleq 2199 df-clel 2202 df-nfc 2338 df-v 2775 |
| This theorem is referenced by: elab 2918 indpi 7462 |
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