Theorem nfraldxy 2404

Description: Not-free for restricted universal quantification where 𝑥 and 𝑦 are distinct. See nfraldya 2406 for a version with 𝑦 and 𝐴 distinct instead. (Contributed by Jim Kingdon, 29-May-2018.)

Hypotheses

Ref	Expression
nfraldxy.2	⊢ Ⅎ𝑦𝜑
nfraldxy.3	⊢ (𝜑 → Ⅎ𝑥𝐴)
nfraldxy.4	⊢ (𝜑 → Ⅎ𝑥𝜓)

Assertion

Ref	Expression
nfraldxy	⊢ (𝜑 → Ⅎ𝑥∀𝑦 ∈ 𝐴 𝜓)

Distinct variable group:   𝑥,𝑦

Allowed substitution hints:   𝜑(𝑥,𝑦)   𝜓(𝑥,𝑦)   𝐴(𝑥,𝑦)

Proof of Theorem nfraldxy

Step	Hyp	Ref	Expression
1		df-ral 2358	. 2 ⊢ (∀𝑦 ∈ 𝐴 𝜓 ↔ ∀𝑦(𝑦 ∈ 𝐴 → 𝜓))
2		nfraldxy.2	. . 3 ⊢ Ⅎ𝑦𝜑
3		nfcv 2223	. . . . . 6 ⊢ Ⅎ𝑥𝑦
4	3	a1i 9	. . . . 5 ⊢ (𝜑 → Ⅎ𝑥𝑦)
5		nfraldxy.3	. . . . 5 ⊢ (𝜑 → Ⅎ𝑥𝐴)
6	4, 5	nfeld 2238	. . . 4 ⊢ (𝜑 → Ⅎ𝑥 𝑦 ∈ 𝐴)
7		nfraldxy.4	. . . 4 ⊢ (𝜑 → Ⅎ𝑥𝜓)
8	6, 7	nfimd 1518	. . 3 ⊢ (𝜑 → Ⅎ𝑥(𝑦 ∈ 𝐴 → 𝜓))
9	2, 8	nfald 1685	. 2 ⊢ (𝜑 → Ⅎ𝑥∀𝑦(𝑦 ∈ 𝐴 → 𝜓))
10	1, 9	nfxfrd 1405	1 ⊢ (𝜑 → Ⅎ𝑥∀𝑦 ∈ 𝐴 𝜓)

Syntax hints:   → wi 4  ∀wal 1283  Ⅎwnf 1390   ∈ wcel 1434  Ⅎwnfc 2210  ∀wral 2353

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-5 1377  ax-7 1378  ax-gen 1379  ax-ie1 1423  ax-ie2 1424  ax-4 1441  ax-17 1460  ax-ial 1468  ax-i5r 1469  ax-ext 2065

This theorem depends on definitions:  df-bi 115  df-nf 1391  df-cleq 2076  df-clel 2079  df-nfc 2212  df-ral 2358

This theorem is referenced by:  nfraldya  2406  nfralxy  2408