Step | Hyp | Ref
| Expression |
1 | | elissetv 2818 |
. . . . 5
⊢ (𝐴 ∈ 𝑉 → ∃𝑧 𝑧 = 𝐴) |
2 | | nfv 1917 |
. . . . . . . 8
⊢
Ⅎ𝑧Ⅎ𝑥𝐴 |
3 | | nfnfc1 2910 |
. . . . . . . 8
⊢
Ⅎ𝑥Ⅎ𝑥𝐴 |
4 | | nfcvd 2908 |
. . . . . . . . . 10
⊢
(Ⅎ𝑥𝐴 → Ⅎ𝑥𝑧) |
5 | | id 22 |
. . . . . . . . . 10
⊢
(Ⅎ𝑥𝐴 → Ⅎ𝑥𝐴) |
6 | 4, 5 | nfeqd 2917 |
. . . . . . . . 9
⊢
(Ⅎ𝑥𝐴 → Ⅎ𝑥 𝑧 = 𝐴) |
7 | 6 | nfnd 1861 |
. . . . . . . 8
⊢
(Ⅎ𝑥𝐴 → Ⅎ𝑥 ¬ 𝑧 = 𝐴) |
8 | | nfvd 1918 |
. . . . . . . 8
⊢
(Ⅎ𝑥𝐴 → Ⅎ𝑧 ¬ 𝑥 = 𝐴) |
9 | | eqeq1 2740 |
. . . . . . . . . 10
⊢ (𝑧 = 𝑥 → (𝑧 = 𝐴 ↔ 𝑥 = 𝐴)) |
10 | 9 | notbid 317 |
. . . . . . . . 9
⊢ (𝑧 = 𝑥 → (¬ 𝑧 = 𝐴 ↔ ¬ 𝑥 = 𝐴)) |
11 | 10 | a1i 11 |
. . . . . . . 8
⊢
(Ⅎ𝑥𝐴 → (𝑧 = 𝑥 → (¬ 𝑧 = 𝐴 ↔ ¬ 𝑥 = 𝐴))) |
12 | 2, 3, 7, 8, 11 | cbv2w 2333 |
. . . . . . 7
⊢
(Ⅎ𝑥𝐴 → (∀𝑧 ¬ 𝑧 = 𝐴 ↔ ∀𝑥 ¬ 𝑥 = 𝐴)) |
13 | | alnex 1783 |
. . . . . . 7
⊢
(∀𝑧 ¬
𝑧 = 𝐴 ↔ ¬ ∃𝑧 𝑧 = 𝐴) |
14 | | alnex 1783 |
. . . . . . 7
⊢
(∀𝑥 ¬
𝑥 = 𝐴 ↔ ¬ ∃𝑥 𝑥 = 𝐴) |
15 | 12, 13, 14 | 3bitr3g 312 |
. . . . . 6
⊢
(Ⅎ𝑥𝐴 → (¬ ∃𝑧 𝑧 = 𝐴 ↔ ¬ ∃𝑥 𝑥 = 𝐴)) |
16 | 15 | con4bid 316 |
. . . . 5
⊢
(Ⅎ𝑥𝐴 → (∃𝑧 𝑧 = 𝐴 ↔ ∃𝑥 𝑥 = 𝐴)) |
17 | 1, 16 | imbitrid 243 |
. . . 4
⊢
(Ⅎ𝑥𝐴 → (𝐴 ∈ 𝑉 → ∃𝑥 𝑥 = 𝐴)) |
18 | 17 | ad2antrr 724 |
. . 3
⊢
(((Ⅎ𝑥𝐴 ∧ Ⅎ𝑥𝜓) ∧ (∀𝑥(𝑥 = 𝐴 → (𝜑 ↔ 𝜓)) ∧ ∀𝑥𝜑)) → (𝐴 ∈ 𝑉 → ∃𝑥 𝑥 = 𝐴)) |
19 | 18 | 3impia 1117 |
. 2
⊢
(((Ⅎ𝑥𝐴 ∧ Ⅎ𝑥𝜓) ∧ (∀𝑥(𝑥 = 𝐴 → (𝜑 ↔ 𝜓)) ∧ ∀𝑥𝜑) ∧ 𝐴 ∈ 𝑉) → ∃𝑥 𝑥 = 𝐴) |
20 | | biimp 214 |
. . . . . . . . 9
⊢ ((𝜑 ↔ 𝜓) → (𝜑 → 𝜓)) |
21 | 20 | imim2i 16 |
. . . . . . . 8
⊢ ((𝑥 = 𝐴 → (𝜑 ↔ 𝜓)) → (𝑥 = 𝐴 → (𝜑 → 𝜓))) |
22 | 21 | com23 86 |
. . . . . . 7
⊢ ((𝑥 = 𝐴 → (𝜑 ↔ 𝜓)) → (𝜑 → (𝑥 = 𝐴 → 𝜓))) |
23 | 22 | imp 407 |
. . . . . 6
⊢ (((𝑥 = 𝐴 → (𝜑 ↔ 𝜓)) ∧ 𝜑) → (𝑥 = 𝐴 → 𝜓)) |
24 | 23 | alanimi 1818 |
. . . . 5
⊢
((∀𝑥(𝑥 = 𝐴 → (𝜑 ↔ 𝜓)) ∧ ∀𝑥𝜑) → ∀𝑥(𝑥 = 𝐴 → 𝜓)) |
25 | | 19.23t 2203 |
. . . . . 6
⊢
(Ⅎ𝑥𝜓 → (∀𝑥(𝑥 = 𝐴 → 𝜓) ↔ (∃𝑥 𝑥 = 𝐴 → 𝜓))) |
26 | 25 | adantl 482 |
. . . . 5
⊢
((Ⅎ𝑥𝐴 ∧ Ⅎ𝑥𝜓) → (∀𝑥(𝑥 = 𝐴 → 𝜓) ↔ (∃𝑥 𝑥 = 𝐴 → 𝜓))) |
27 | 24, 26 | imbitrid 243 |
. . . 4
⊢
((Ⅎ𝑥𝐴 ∧ Ⅎ𝑥𝜓) → ((∀𝑥(𝑥 = 𝐴 → (𝜑 ↔ 𝜓)) ∧ ∀𝑥𝜑) → (∃𝑥 𝑥 = 𝐴 → 𝜓))) |
28 | 27 | imp 407 |
. . 3
⊢
(((Ⅎ𝑥𝐴 ∧ Ⅎ𝑥𝜓) ∧ (∀𝑥(𝑥 = 𝐴 → (𝜑 ↔ 𝜓)) ∧ ∀𝑥𝜑)) → (∃𝑥 𝑥 = 𝐴 → 𝜓)) |
29 | 28 | 3adant3 1132 |
. 2
⊢
(((Ⅎ𝑥𝐴 ∧ Ⅎ𝑥𝜓) ∧ (∀𝑥(𝑥 = 𝐴 → (𝜑 ↔ 𝜓)) ∧ ∀𝑥𝜑) ∧ 𝐴 ∈ 𝑉) → (∃𝑥 𝑥 = 𝐴 → 𝜓)) |
30 | 19, 29 | mpd 15 |
1
⊢
(((Ⅎ𝑥𝐴 ∧ Ⅎ𝑥𝜓) ∧ (∀𝑥(𝑥 = 𝐴 → (𝜑 ↔ 𝜓)) ∧ ∀𝑥𝜑) ∧ 𝐴 ∈ 𝑉) → 𝜓) |