Theorem cbvrald 16987

Description: Rule used to change bound variables, using implicit substitution. (Contributed by BJ, 22-Nov-2019.)

Hypotheses

Ref	Expression
cbvrald.nf0	⊢ Ⅎ𝑥𝜑
cbvrald.nf1	⊢ Ⅎ𝑦𝜑
cbvrald.nf2	⊢ (𝜑 → Ⅎ𝑦𝜓)
cbvrald.nf3	⊢ (𝜑 → Ⅎ𝑥𝜒)
cbvrald.is	⊢ (𝜑 → (𝑥 = 𝑦 → (𝜓 ↔ 𝜒)))

Assertion

Ref	Expression
cbvrald	⊢ (𝜑 → (∀𝑥 ∈ 𝐴 𝜓 ↔ ∀𝑦 ∈ 𝐴 𝜒))

Distinct variable groups:   𝑥,𝐴   𝑦,𝐴

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

Proof of Theorem cbvrald

Dummy variable 𝑧 is distinct from all other variables.

Step	Hyp	Ref	Expression
1		cbvrald.nf0	. . . 4 ⊢ Ⅎ𝑥𝜑
2		nfv 1581	. . . 4 ⊢ Ⅎ𝑧𝜑
3		nfv 1581	. . . . . 6 ⊢ Ⅎ𝑧 𝑥 ∈ 𝐴
4	3	a1i 9	. . . . 5 ⊢ (𝜑 → Ⅎ𝑧 𝑥 ∈ 𝐴)
5		nfv 1581	. . . . . 6 ⊢ Ⅎ𝑧𝜓
6	5	a1i 9	. . . . 5 ⊢ (𝜑 → Ⅎ𝑧𝜓)
7	4, 6	nfimd 1638	. . . 4 ⊢ (𝜑 → Ⅎ𝑧(𝑥 ∈ 𝐴 → 𝜓))
8		nfv 1581	. . . . . 6 ⊢ Ⅎ𝑥 𝑧 ∈ 𝐴
9	8	a1i 9	. . . . 5 ⊢ (𝜑 → Ⅎ𝑥 𝑧 ∈ 𝐴)
10		nfs1v 1999	. . . . . 6 ⊢ Ⅎ𝑥[𝑧 / 𝑥]𝜓
11	10	a1i 9	. . . . 5 ⊢ (𝜑 → Ⅎ𝑥[𝑧 / 𝑥]𝜓)
12	9, 11	nfimd 1638	. . . 4 ⊢ (𝜑 → Ⅎ𝑥(𝑧 ∈ 𝐴 → [𝑧 / 𝑥]𝜓))
13		eleq1 2301	. . . . . . 7 ⊢ (𝑥 = 𝑧 → (𝑥 ∈ 𝐴 ↔ 𝑧 ∈ 𝐴))
14	13	adantl 277	. . . . . 6 ⊢ ((𝜑 ∧ 𝑥 = 𝑧) → (𝑥 ∈ 𝐴 ↔ 𝑧 ∈ 𝐴))
15		sbequ12 1824	. . . . . . 7 ⊢ (𝑥 = 𝑧 → (𝜓 ↔ [𝑧 / 𝑥]𝜓))
16	15	adantl 277	. . . . . 6 ⊢ ((𝜑 ∧ 𝑥 = 𝑧) → (𝜓 ↔ [𝑧 / 𝑥]𝜓))
17	14, 16	imbi12d 234	. . . . 5 ⊢ ((𝜑 ∧ 𝑥 = 𝑧) → ((𝑥 ∈ 𝐴 → 𝜓) ↔ (𝑧 ∈ 𝐴 → [𝑧 / 𝑥]𝜓)))
18	17	ex 115	. . . 4 ⊢ (𝜑 → (𝑥 = 𝑧 → ((𝑥 ∈ 𝐴 → 𝜓) ↔ (𝑧 ∈ 𝐴 → [𝑧 / 𝑥]𝜓))))
19	1, 2, 7, 12, 18	cbv2 1802	. . 3 ⊢ (𝜑 → (∀𝑥(𝑥 ∈ 𝐴 → 𝜓) ↔ ∀𝑧(𝑧 ∈ 𝐴 → [𝑧 / 𝑥]𝜓)))
20		cbvrald.nf1	. . . 4 ⊢ Ⅎ𝑦𝜑
21		nfv 1581	. . . . . 6 ⊢ Ⅎ𝑦 𝑧 ∈ 𝐴
22	21	a1i 9	. . . . 5 ⊢ (𝜑 → Ⅎ𝑦 𝑧 ∈ 𝐴)
23		cbvrald.nf2	. . . . . 6 ⊢ (𝜑 → Ⅎ𝑦𝜓)
24	1, 23	nfsbd 2037	. . . . 5 ⊢ (𝜑 → Ⅎ𝑦[𝑧 / 𝑥]𝜓)
25	22, 24	nfimd 1638	. . . 4 ⊢ (𝜑 → Ⅎ𝑦(𝑧 ∈ 𝐴 → [𝑧 / 𝑥]𝜓))
26		nfv 1581	. . . . . 6 ⊢ Ⅎ𝑧 𝑦 ∈ 𝐴
27	26	a1i 9	. . . . 5 ⊢ (𝜑 → Ⅎ𝑧 𝑦 ∈ 𝐴)
28		nfv 1581	. . . . . 6 ⊢ Ⅎ𝑧𝜒
29	28	a1i 9	. . . . 5 ⊢ (𝜑 → Ⅎ𝑧𝜒)
30	27, 29	nfimd 1638	. . . 4 ⊢ (𝜑 → Ⅎ𝑧(𝑦 ∈ 𝐴 → 𝜒))
31		eleq1 2301	. . . . . . 7 ⊢ (𝑧 = 𝑦 → (𝑧 ∈ 𝐴 ↔ 𝑦 ∈ 𝐴))
32	31	adantl 277	. . . . . 6 ⊢ ((𝜑 ∧ 𝑧 = 𝑦) → (𝑧 ∈ 𝐴 ↔ 𝑦 ∈ 𝐴))
33		sbequ 1893	. . . . . . 7 ⊢ (𝑧 = 𝑦 → ([𝑧 / 𝑥]𝜓 ↔ [𝑦 / 𝑥]𝜓))
34		cbvrald.nf3	. . . . . . . 8 ⊢ (𝜑 → Ⅎ𝑥𝜒)
35		cbvrald.is	. . . . . . . 8 ⊢ (𝜑 → (𝑥 = 𝑦 → (𝜓 ↔ 𝜒)))
36	1, 34, 35	sbied 1841	. . . . . . 7 ⊢ (𝜑 → ([𝑦 / 𝑥]𝜓 ↔ 𝜒))
37	33, 36	sylan9bbr 467	. . . . . 6 ⊢ ((𝜑 ∧ 𝑧 = 𝑦) → ([𝑧 / 𝑥]𝜓 ↔ 𝜒))
38	32, 37	imbi12d 234	. . . . 5 ⊢ ((𝜑 ∧ 𝑧 = 𝑦) → ((𝑧 ∈ 𝐴 → [𝑧 / 𝑥]𝜓) ↔ (𝑦 ∈ 𝐴 → 𝜒)))
39	38	ex 115	. . . 4 ⊢ (𝜑 → (𝑧 = 𝑦 → ((𝑧 ∈ 𝐴 → [𝑧 / 𝑥]𝜓) ↔ (𝑦 ∈ 𝐴 → 𝜒))))
40	2, 20, 25, 30, 39	cbv2 1802	. . 3 ⊢ (𝜑 → (∀𝑧(𝑧 ∈ 𝐴 → [𝑧 / 𝑥]𝜓) ↔ ∀𝑦(𝑦 ∈ 𝐴 → 𝜒)))
41	19, 40	bitrd 188	. 2 ⊢ (𝜑 → (∀𝑥(𝑥 ∈ 𝐴 → 𝜓) ↔ ∀𝑦(𝑦 ∈ 𝐴 → 𝜒)))
42		df-ral 2533	. 2 ⊢ (∀𝑥 ∈ 𝐴 𝜓 ↔ ∀𝑥(𝑥 ∈ 𝐴 → 𝜓))
43		df-ral 2533	. 2 ⊢ (∀𝑦 ∈ 𝐴 𝜒 ↔ ∀𝑦(𝑦 ∈ 𝐴 → 𝜒))
44	41, 42, 43	3bitr4g 223	1 ⊢ (𝜑 → (∀𝑥 ∈ 𝐴 𝜓 ↔ ∀𝑦 ∈ 𝐴 𝜒))

This proof depends on syntax axioms:   → wi 4   ∧ wa 104   ↔ wb 105  ∀wal 1400  Ⅎwnf 1513  [wsb 1815   ∈ wcel 2209  ∀wral 2528

This proof depends on axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 106  ax-ia2 107  ax-ia3 108  ax-io 721  ax-5 1500  ax-7 1501  ax-gen 1502  ax-ie1 1546  ax-ie2 1547  ax-8 1557  ax-10 1558  ax-11 1559  ax-i12 1560  ax-bndl 1562  ax-4 1563  ax-17 1579  ax-i9 1583  ax-ial 1587  ax-i5r 1588  ax-ext 2220

This proof depends on definitions:  df-bi 117  df-nf 1514  df-sb 1816  df-cleq 2231  df-clel 2234  df-ral 2533

This theorem is used by:  setindft  17162