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Mirrors > Home > ILE Home > Th. List > nfraldxy | GIF version |
Description: Not-free for restricted universal quantification where 𝑥 and 𝑦 are distinct. See nfraldya 2423 for a version with 𝑦 and 𝐴 distinct instead. (Contributed by Jim Kingdon, 29-May-2018.) |
Ref | Expression |
---|---|
nfraldxy.2 | ⊢ Ⅎ𝑦𝜑 |
nfraldxy.3 | ⊢ (𝜑 → Ⅎ𝑥𝐴) |
nfraldxy.4 | ⊢ (𝜑 → Ⅎ𝑥𝜓) |
Ref | Expression |
---|---|
nfraldxy | ⊢ (𝜑 → Ⅎ𝑥∀𝑦 ∈ 𝐴 𝜓) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | df-ral 2375 | . 2 ⊢ (∀𝑦 ∈ 𝐴 𝜓 ↔ ∀𝑦(𝑦 ∈ 𝐴 → 𝜓)) | |
2 | nfraldxy.2 | . . 3 ⊢ Ⅎ𝑦𝜑 | |
3 | nfcv 2235 | . . . . . 6 ⊢ Ⅎ𝑥𝑦 | |
4 | 3 | a1i 9 | . . . . 5 ⊢ (𝜑 → Ⅎ𝑥𝑦) |
5 | nfraldxy.3 | . . . . 5 ⊢ (𝜑 → Ⅎ𝑥𝐴) | |
6 | 4, 5 | nfeld 2251 | . . . 4 ⊢ (𝜑 → Ⅎ𝑥 𝑦 ∈ 𝐴) |
7 | nfraldxy.4 | . . . 4 ⊢ (𝜑 → Ⅎ𝑥𝜓) | |
8 | 6, 7 | nfimd 1529 | . . 3 ⊢ (𝜑 → Ⅎ𝑥(𝑦 ∈ 𝐴 → 𝜓)) |
9 | 2, 8 | nfald 1697 | . 2 ⊢ (𝜑 → Ⅎ𝑥∀𝑦(𝑦 ∈ 𝐴 → 𝜓)) |
10 | 1, 9 | nfxfrd 1416 | 1 ⊢ (𝜑 → Ⅎ𝑥∀𝑦 ∈ 𝐴 𝜓) |
Colors of variables: wff set class |
Syntax hints: → wi 4 ∀wal 1294 Ⅎwnf 1401 ∈ wcel 1445 Ⅎwnfc 2222 ∀wral 2370 |
This theorem was proved from axioms: ax-1 5 ax-2 6 ax-mp 7 ax-ia1 105 ax-ia2 106 ax-ia3 107 ax-5 1388 ax-7 1389 ax-gen 1390 ax-ie1 1434 ax-ie2 1435 ax-4 1452 ax-17 1471 ax-ial 1479 ax-i5r 1480 ax-ext 2077 |
This theorem depends on definitions: df-bi 116 df-nf 1402 df-cleq 2088 df-clel 2091 df-nfc 2224 df-ral 2375 |
This theorem is referenced by: nfraldya 2423 nfralxy 2425 |
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