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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 2352 | . . 3 ⊢ Ⅎ𝑥𝐴 | |
| 3 | elabf.1 | . . 3 ⊢ Ⅎ𝑥𝜓 | |
| 4 | elabf.3 | . . 3 ⊢ (𝑥 = 𝐴 → (𝜑 ↔ 𝜓)) | |
| 5 | 2, 3, 4 | elabgf 2925 | . 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 1375 Ⅎwnf 1486 ∈ wcel 2180 {cab 2195 Vcvv 2779 |
| 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 713 ax-5 1473 ax-7 1474 ax-gen 1475 ax-ie1 1519 ax-ie2 1520 ax-8 1530 ax-10 1531 ax-11 1532 ax-i12 1533 ax-bndl 1535 ax-4 1536 ax-17 1552 ax-i9 1556 ax-ial 1560 ax-i5r 1561 ax-ext 2191 |
| This theorem depends on definitions: df-bi 117 df-tru 1378 df-nf 1487 df-sb 1789 df-clab 2196 df-cleq 2202 df-clel 2205 df-nfc 2341 df-v 2781 |
| This theorem is referenced by: elab 2927 indpi 7497 |
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