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Theorem nfraldya 2512
Description: Not-free for restricted universal quantification where 𝑦 and 𝐴 are distinct. See nfraldxy 2510 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 2460 . 2 (∀𝑦𝐴 𝜓 ↔ ∀𝑦(𝑦𝐴𝜓))
2 sbim 1953 . . . . . 6 ([𝑧 / 𝑦](𝑦𝐴𝜓) ↔ ([𝑧 / 𝑦]𝑦𝐴 → [𝑧 / 𝑦]𝜓))
3 clelsb1 2282 . . . . . . 7 ([𝑧 / 𝑦]𝑦𝐴𝑧𝐴)
43imbi1i 238 . . . . . 6 (([𝑧 / 𝑦]𝑦𝐴 → [𝑧 / 𝑦]𝜓) ↔ (𝑧𝐴 → [𝑧 / 𝑦]𝜓))
52, 4bitri 184 . . . . 5 ([𝑧 / 𝑦](𝑦𝐴𝜓) ↔ (𝑧𝐴 → [𝑧 / 𝑦]𝜓))
65albii 1470 . . . 4 (∀𝑧[𝑧 / 𝑦](𝑦𝐴𝜓) ↔ ∀𝑧(𝑧𝐴 → [𝑧 / 𝑦]𝜓))
7 nfv 1528 . . . . 5 𝑧(𝑦𝐴𝜓)
87sb8 1856 . . . 4 (∀𝑦(𝑦𝐴𝜓) ↔ ∀𝑧[𝑧 / 𝑦](𝑦𝐴𝜓))
9 df-ral 2460 . . . 4 (∀𝑧𝐴 [𝑧 / 𝑦]𝜓 ↔ ∀𝑧(𝑧𝐴 → [𝑧 / 𝑦]𝜓))
106, 8, 93bitr4i 212 . . 3 (∀𝑦(𝑦𝐴𝜓) ↔ ∀𝑧𝐴 [𝑧 / 𝑦]𝜓)
11 nfv 1528 . . . 4 𝑧𝜑
12 nfraldya.3 . . . 4 (𝜑𝑥𝐴)
13 nfraldya.2 . . . . 5 𝑦𝜑
14 nfraldya.4 . . . . 5 (𝜑 → Ⅎ𝑥𝜓)
1513, 14nfsbd 1977 . . . 4 (𝜑 → Ⅎ𝑥[𝑧 / 𝑦]𝜓)
1611, 12, 15nfraldxy 2510 . . 3 (𝜑 → Ⅎ𝑥𝑧𝐴 [𝑧 / 𝑦]𝜓)
1710, 16nfxfrd 1475 . 2 (𝜑 → Ⅎ𝑥𝑦(𝑦𝐴𝜓))
181, 17nfxfrd 1475 1 (𝜑 → Ⅎ𝑥𝑦𝐴 𝜓)
Colors of variables: wff set class
Syntax hints:  wi 4  wal 1351  wnf 1460  [wsb 1762  wcel 2148  wnfc 2306  wral 2455
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 709  ax-5 1447  ax-7 1448  ax-gen 1449  ax-ie1 1493  ax-ie2 1494  ax-8 1504  ax-10 1505  ax-11 1506  ax-i12 1507  ax-bndl 1509  ax-4 1510  ax-17 1526  ax-i9 1530  ax-ial 1534  ax-i5r 1535  ax-ext 2159
This theorem depends on definitions:  df-bi 117  df-nf 1461  df-sb 1763  df-cleq 2170  df-clel 2173  df-nfc 2308  df-ral 2460
This theorem is referenced by:  nfralya  2517
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