Theorem rspc2daf 32486

Description: Double restricted specialization, using implicit substitution. (Contributed by Thierry Arnoux, 4-Jul-2023.)

Hypotheses

Ref	Expression
sbc2iedf.1	⊢ Ⅎ𝑥𝜑
sbc2iedf.2	⊢ Ⅎ𝑦𝜑
sbc2iedf.3	⊢ Ⅎ𝑥𝜒
sbc2iedf.4	⊢ Ⅎ𝑦𝜒
sbc2iedf.5	⊢ (𝜑 → 𝐴 ∈ 𝑉)
sbc2iedf.6	⊢ (𝜑 → 𝐵 ∈ 𝑊)
sbc2iedf.7	⊢ ((𝜑 ∧ (𝑥 = 𝐴 ∧ 𝑦 = 𝐵)) → (𝜓 ↔ 𝜒))
rspc2daf.8	⊢ (𝜑 → ∀𝑥 ∈ 𝑉 ∀𝑦 ∈ 𝑊 𝜓)

Assertion

Ref	Expression
rspc2daf	⊢ (𝜑 → 𝜒)

Distinct variable groups:   𝑥,𝐴,𝑦   𝑥,𝐵,𝑦   𝑥,𝑉   𝑥,𝑊,𝑦

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

Proof of Theorem rspc2daf

Step	Hyp	Ref	Expression
1		rspc2daf.8	. . . 4 ⊢ (𝜑 → ∀𝑥 ∈ 𝑉 ∀𝑦 ∈ 𝑊 𝜓)
2		sbc2iedf.1	. . . . 5 ⊢ Ⅎ𝑥𝜑
3		nfcv 2904	. . . . . 6 ⊢ Ⅎ𝑥𝑊
4		nfsbc1v 3818	. . . . . 6 ⊢ Ⅎ𝑥[𝐴 / 𝑥]𝜓
5	3, 4	nfralw 3312	. . . . 5 ⊢ Ⅎ𝑥∀𝑦 ∈ 𝑊 [𝐴 / 𝑥]𝜓
6		sbc2iedf.5	. . . . 5 ⊢ (𝜑 → 𝐴 ∈ 𝑉)
7		sbc2iedf.2	. . . . . . 7 ⊢ Ⅎ𝑦𝜑
8		nfv 1913	. . . . . . 7 ⊢ Ⅎ𝑦 𝑥 = 𝐴
9	7, 8	nfan 1898	. . . . . 6 ⊢ Ⅎ𝑦(𝜑 ∧ 𝑥 = 𝐴)
10		sbceq1a 3809	. . . . . . 7 ⊢ (𝑥 = 𝐴 → (𝜓 ↔ [𝐴 / 𝑥]𝜓))
11	10	adantl 481	. . . . . 6 ⊢ ((𝜑 ∧ 𝑥 = 𝐴) → (𝜓 ↔ [𝐴 / 𝑥]𝜓))
12	9, 11	ralbid 3274	. . . . 5 ⊢ ((𝜑 ∧ 𝑥 = 𝐴) → (∀𝑦 ∈ 𝑊 𝜓 ↔ ∀𝑦 ∈ 𝑊 [𝐴 / 𝑥]𝜓))
13	2, 5, 6, 12	rspcdf 3618	. . . 4 ⊢ (𝜑 → (∀𝑥 ∈ 𝑉 ∀𝑦 ∈ 𝑊 𝜓 → ∀𝑦 ∈ 𝑊 [𝐴 / 𝑥]𝜓))
14	1, 13	mpd 15	. . 3 ⊢ (𝜑 → ∀𝑦 ∈ 𝑊 [𝐴 / 𝑥]𝜓)
15		nfsbc1v 3818	. . . 4 ⊢ Ⅎ𝑦[𝐵 / 𝑦][𝐴 / 𝑥]𝜓
16		sbc2iedf.6	. . . 4 ⊢ (𝜑 → 𝐵 ∈ 𝑊)
17		sbceq1a 3809	. . . . 5 ⊢ (𝑦 = 𝐵 → ([𝐴 / 𝑥]𝜓 ↔ [𝐵 / 𝑦][𝐴 / 𝑥]𝜓))
18	17	adantl 481	. . . 4 ⊢ ((𝜑 ∧ 𝑦 = 𝐵) → ([𝐴 / 𝑥]𝜓 ↔ [𝐵 / 𝑦][𝐴 / 𝑥]𝜓))
19	7, 15, 16, 18	rspcdf 3618	. . 3 ⊢ (𝜑 → (∀𝑦 ∈ 𝑊 [𝐴 / 𝑥]𝜓 → [𝐵 / 𝑦][𝐴 / 𝑥]𝜓))
20	14, 19	mpd 15	. 2 ⊢ (𝜑 → [𝐵 / 𝑦][𝐴 / 𝑥]𝜓)
21		sbc2iedf.3	. . . 4 ⊢ Ⅎ𝑥𝜒
22		sbc2iedf.4	. . . 4 ⊢ Ⅎ𝑦𝜒
23		sbc2iedf.7	. . . 4 ⊢ ((𝜑 ∧ (𝑥 = 𝐴 ∧ 𝑦 = 𝐵)) → (𝜓 ↔ 𝜒))
24	2, 7, 21, 22, 6, 16, 23	sbc2iedf 32485	. . 3 ⊢ (𝜑 → ([𝐴 / 𝑥][𝐵 / 𝑦]𝜓 ↔ 𝜒))
25		sbccom 3887	. . 3 ⊢ ([𝐴 / 𝑥][𝐵 / 𝑦]𝜓 ↔ [𝐵 / 𝑦][𝐴 / 𝑥]𝜓)
26	24, 25	bitr3di 286	. 2 ⊢ (𝜑 → (𝜒 ↔ [𝐵 / 𝑦][𝐴 / 𝑥]𝜓))
27	20, 26	mpbird 257	1 ⊢ (𝜑 → 𝜒)

Syntax hints:   → wi 4   ↔ wb 206   ∧ wa 395   = wceq 1537  Ⅎwnf 1781   ∈ wcel 2103  ∀wral 3063  [wsbc 3798

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1793  ax-4 1807  ax-5 1909  ax-6 1967  ax-7 2007  ax-8 2105  ax-9 2113  ax-10 2136  ax-11 2153  ax-12 2173  ax-ext 2705

This theorem depends on definitions:  df-bi 207  df-an 396  df-or 847  df-3an 1089  df-tru 1540  df-ex 1778  df-nf 1782  df-sb 2065  df-clab 2712  df-cleq 2726  df-clel 2813  df-nfc 2890  df-ral 3064  df-v 3484  df-sbc 3799

This theorem is referenced by:  opreu2reuALT  32496