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Mirrors > Home > ILE Home > Th. List > nfraldw | GIF version |
Description: Not-free for restricted universal quantification where 𝑥 and 𝑦 are distinct. See nfraldya 2505 for a version with 𝑦 and 𝐴 distinct instead. (Contributed by NM, 15-Feb-2013.) (Revised by Gino Giotto, 10-Jan-2024.) |
Ref | Expression |
---|---|
nfraldw.1 | ⊢ Ⅎ𝑦𝜑 |
nfraldw.2 | ⊢ (𝜑 → Ⅎ𝑥𝐴) |
nfraldw.3 | ⊢ (𝜑 → Ⅎ𝑥𝜓) |
Ref | Expression |
---|---|
nfraldw | ⊢ (𝜑 → Ⅎ𝑥∀𝑦 ∈ 𝐴 𝜓) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | df-ral 2453 | . 2 ⊢ (∀𝑦 ∈ 𝐴 𝜓 ↔ ∀𝑦(𝑦 ∈ 𝐴 → 𝜓)) | |
2 | nfraldw.1 | . . 3 ⊢ Ⅎ𝑦𝜑 | |
3 | nfcvd 2313 | . . . . 5 ⊢ (𝜑 → Ⅎ𝑥𝑦) | |
4 | nfraldw.2 | . . . . 5 ⊢ (𝜑 → Ⅎ𝑥𝐴) | |
5 | 3, 4 | nfeld 2328 | . . . 4 ⊢ (𝜑 → Ⅎ𝑥 𝑦 ∈ 𝐴) |
6 | nfraldw.3 | . . . 4 ⊢ (𝜑 → Ⅎ𝑥𝜓) | |
7 | 5, 6 | nfimd 1578 | . . 3 ⊢ (𝜑 → Ⅎ𝑥(𝑦 ∈ 𝐴 → 𝜓)) |
8 | 2, 7 | nfald 1753 | . 2 ⊢ (𝜑 → Ⅎ𝑥∀𝑦(𝑦 ∈ 𝐴 → 𝜓)) |
9 | 1, 8 | nfxfrd 1468 | 1 ⊢ (𝜑 → Ⅎ𝑥∀𝑦 ∈ 𝐴 𝜓) |
Colors of variables: wff set class |
Syntax hints: → wi 4 ∀wal 1346 Ⅎwnf 1453 ∈ wcel 2141 Ⅎwnfc 2299 ∀wral 2448 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-ia1 105 ax-ia2 106 ax-ia3 107 ax-5 1440 ax-7 1441 ax-gen 1442 ax-ie1 1486 ax-ie2 1487 ax-4 1503 ax-17 1519 ax-ial 1527 ax-i5r 1528 ax-ext 2152 |
This theorem depends on definitions: df-bi 116 df-nf 1454 df-cleq 2163 df-clel 2166 df-nfc 2301 df-ral 2453 |
This theorem is referenced by: nfralw 2507 |
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