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Theorem nfraldya 2400
Description: Not-free for restricted universal quantification where 𝑦 and 𝐴 are distinct. See nfraldxy 2398 for a version with 𝑥 and 𝑦 distinct instead. (Contributed by Jim Kingdon, 30-May-2018.)
Hypotheses
Ref Expression
nfraldya.2 𝑦𝜑
nfraldya.3 (𝜑𝑥𝐴)
nfraldya.4 (𝜑 → Ⅎ𝑥𝜓)
Assertion
Ref Expression
nfraldya (𝜑 → Ⅎ𝑥𝑦𝐴 𝜓)
Distinct variable group:   𝑦,𝐴
Allowed substitution hints:   𝜑(𝑥,𝑦)   𝜓(𝑥,𝑦)   𝐴(𝑥)

Proof of Theorem nfraldya
Dummy variable 𝑧 is distinct from all other variables.
StepHypRef Expression
1 df-ral 2353 . 2 (∀𝑦𝐴 𝜓 ↔ ∀𝑦(𝑦𝐴𝜓))
2 sbim 1868 . . . . . 6 ([𝑧 / 𝑦](𝑦𝐴𝜓) ↔ ([𝑧 / 𝑦]𝑦𝐴 → [𝑧 / 𝑦]𝜓))
3 clelsb3 2183 . . . . . . 7 ([𝑧 / 𝑦]𝑦𝐴𝑧𝐴)
43imbi1i 236 . . . . . 6 (([𝑧 / 𝑦]𝑦𝐴 → [𝑧 / 𝑦]𝜓) ↔ (𝑧𝐴 → [𝑧 / 𝑦]𝜓))
52, 4bitri 182 . . . . 5 ([𝑧 / 𝑦](𝑦𝐴𝜓) ↔ (𝑧𝐴 → [𝑧 / 𝑦]𝜓))
65albii 1399 . . . 4 (∀𝑧[𝑧 / 𝑦](𝑦𝐴𝜓) ↔ ∀𝑧(𝑧𝐴 → [𝑧 / 𝑦]𝜓))
7 nfv 1461 . . . . 5 𝑧(𝑦𝐴𝜓)
87sb8 1777 . . . 4 (∀𝑦(𝑦𝐴𝜓) ↔ ∀𝑧[𝑧 / 𝑦](𝑦𝐴𝜓))
9 df-ral 2353 . . . 4 (∀𝑧𝐴 [𝑧 / 𝑦]𝜓 ↔ ∀𝑧(𝑧𝐴 → [𝑧 / 𝑦]𝜓))
106, 8, 93bitr4i 210 . . 3 (∀𝑦(𝑦𝐴𝜓) ↔ ∀𝑧𝐴 [𝑧 / 𝑦]𝜓)
11 nfv 1461 . . . 4 𝑧𝜑
12 nfraldya.3 . . . 4 (𝜑𝑥𝐴)
13 nfraldya.2 . . . . 5 𝑦𝜑
14 nfraldya.4 . . . . 5 (𝜑 → Ⅎ𝑥𝜓)
1513, 14nfsbd 1892 . . . 4 (𝜑 → Ⅎ𝑥[𝑧 / 𝑦]𝜓)
1611, 12, 15nfraldxy 2398 . . 3 (𝜑 → Ⅎ𝑥𝑧𝐴 [𝑧 / 𝑦]𝜓)
1710, 16nfxfrd 1404 . 2 (𝜑 → Ⅎ𝑥𝑦(𝑦𝐴𝜓))
181, 17nfxfrd 1404 1 (𝜑 → Ⅎ𝑥𝑦𝐴 𝜓)
Colors of variables: wff set class
Syntax hints:  wi 4  wal 1282  wnf 1389  wcel 1433  [wsb 1685  wnfc 2206  wral 2348
This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-mp 7  ax-ia1 104  ax-ia2 105  ax-ia3 106  ax-io 662  ax-5 1376  ax-7 1377  ax-gen 1378  ax-ie1 1422  ax-ie2 1423  ax-8 1435  ax-10 1436  ax-11 1437  ax-i12 1438  ax-bndl 1439  ax-4 1440  ax-17 1459  ax-i9 1463  ax-ial 1467  ax-i5r 1468  ax-ext 2063
This theorem depends on definitions:  df-bi 115  df-nf 1390  df-sb 1686  df-cleq 2074  df-clel 2077  df-nfc 2208  df-ral 2353
This theorem is referenced by:  nfralya  2404
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