Step | Hyp | Ref
| Expression |
1 | | cbvralsv 2846 |
. 2
⊢ (∀x ∈ (A ×
B)φ
↔ ∀w ∈ (A × B)[w / x]φ) |
2 | | cbvralsv 2846 |
. . . 4
⊢ (∀z ∈ B [u / y]ψ ↔ ∀v ∈ B [v / z][u / y]ψ) |
3 | 2 | ralbii 2638 |
. . 3
⊢ (∀u ∈ A ∀z ∈ B [u / y]ψ ↔ ∀u ∈ A ∀v ∈ B [v / z][u / y]ψ) |
4 | | nfv 1619 |
. . . 4
⊢ Ⅎu∀z ∈ B ψ |
5 | | nfcv 2489 |
. . . . 5
⊢
ℲyB |
6 | | nfv 1619 |
. . . . . 6
⊢ Ⅎuψ |
7 | 6 | nfs1 2044 |
. . . . 5
⊢ Ⅎy[u / y]ψ |
8 | 5, 7 | nfral 2667 |
. . . 4
⊢ Ⅎy∀z ∈ B [u / y]ψ |
9 | | sbequ12 1919 |
. . . . 5
⊢ (y = u →
(ψ ↔ [u / y]ψ)) |
10 | 9 | ralbidv 2634 |
. . . 4
⊢ (y = u →
(∀z
∈ B ψ ↔ ∀z ∈ B [u / y]ψ)) |
11 | 4, 8, 10 | cbvral 2831 |
. . 3
⊢ (∀y ∈ A ∀z ∈ B ψ ↔ ∀u ∈ A ∀z ∈ B [u / y]ψ) |
12 | | vex 2862 |
. . . . . 6
⊢ u ∈
V |
13 | | vex 2862 |
. . . . . 6
⊢ v ∈
V |
14 | 12, 13 | eqvinop 4606 |
. . . . 5
⊢ (w = 〈u, v〉 ↔ ∃y∃z(w = 〈y, z〉 ∧ 〈y, z〉 = 〈u, v〉)) |
15 | | ralxpf.1 |
. . . . . . . 8
⊢ Ⅎyφ |
16 | 15 | nfsb 2109 |
. . . . . . 7
⊢ Ⅎy[w / x]φ |
17 | 7 | nfsb 2109 |
. . . . . . 7
⊢ Ⅎy[v / z][u / y]ψ |
18 | 16, 17 | nfbi 1834 |
. . . . . 6
⊢ Ⅎy([w / x]φ ↔
[v / z][u / y]ψ) |
19 | | ralxpf.2 |
. . . . . . . . 9
⊢ Ⅎzφ |
20 | 19 | nfsb 2109 |
. . . . . . . 8
⊢ Ⅎz[w / x]φ |
21 | | nfv 1619 |
. . . . . . . . 9
⊢ Ⅎv[u / y]ψ |
22 | 21 | nfs1 2044 |
. . . . . . . 8
⊢ Ⅎz[v / z][u / y]ψ |
23 | 20, 22 | nfbi 1834 |
. . . . . . 7
⊢ Ⅎz([w / x]φ ↔
[v / z][u / y]ψ) |
24 | | ralxpf.3 |
. . . . . . . . 9
⊢ Ⅎxψ |
25 | | ralxpf.4 |
. . . . . . . . 9
⊢ (x = 〈y, z〉 → (φ
↔ ψ)) |
26 | 24, 25 | sbhypf 2904 |
. . . . . . . 8
⊢ (w = 〈y, z〉 → ([w /
x]φ
↔ ψ)) |
27 | | opth 4602 |
. . . . . . . . 9
⊢ (〈y, z〉 = 〈u, v〉 ↔
(y = u
∧ z =
v)) |
28 | | sbequ12 1919 |
. . . . . . . . . 10
⊢ (z = v →
([u / y]ψ ↔
[v / z][u / y]ψ)) |
29 | 9, 28 | sylan9bb 680 |
. . . . . . . . 9
⊢ ((y = u ∧ z = v) → (ψ
↔ [v / z][u / y]ψ)) |
30 | 27, 29 | sylbi 187 |
. . . . . . . 8
⊢ (〈y, z〉 = 〈u, v〉 → (ψ ↔ [v / z][u / y]ψ)) |
31 | 26, 30 | sylan9bb 680 |
. . . . . . 7
⊢ ((w = 〈y, z〉 ∧ 〈y, z〉 = 〈u, v〉) →
([w / x]φ ↔
[v / z][u / y]ψ)) |
32 | 23, 31 | exlimi 1803 |
. . . . . 6
⊢ (∃z(w = 〈y, z〉 ∧ 〈y, z〉 = 〈u, v〉) →
([w / x]φ ↔
[v / z][u / y]ψ)) |
33 | 18, 32 | exlimi 1803 |
. . . . 5
⊢ (∃y∃z(w = 〈y, z〉 ∧ 〈y, z〉 = 〈u, v〉) →
([w / x]φ ↔
[v / z][u / y]ψ)) |
34 | 14, 33 | sylbi 187 |
. . . 4
⊢ (w = 〈u, v〉 → ([w /
x]φ
↔ [v / z][u / y]ψ)) |
35 | 34 | ralxp 4825 |
. . 3
⊢ (∀w ∈ (A ×
B)[w /
x]φ
↔ ∀u ∈ A ∀v ∈ B [v / z][u / y]ψ) |
36 | 3, 11, 35 | 3bitr4ri 269 |
. 2
⊢ (∀w ∈ (A ×
B)[w /
x]φ
↔ ∀y ∈ A ∀z ∈ B ψ) |
37 | 1, 36 | bitri 240 |
1
⊢ (∀x ∈ (A ×
B)φ
↔ ∀y ∈ A ∀z ∈ B ψ) |