Step | Hyp | Ref
| Expression |
1 | | alexn 1848 |
. 2
⊢
(∀𝑥∃𝑦 ¬ 𝑦 ∈ 𝑥 ↔ ¬ ∃𝑥∀𝑦 𝑦 ∈ 𝑥) |
2 | | ax-sep 5218 |
. . 3
⊢
∃𝑦∀𝑧(𝑧 ∈ 𝑦 ↔ (𝑧 ∈ 𝑥 ∧ ¬ 𝑧 ∈ 𝑧)) |
3 | | elequ1 2115 |
. . . . . 6
⊢ (𝑧 = 𝑦 → (𝑧 ∈ 𝑦 ↔ 𝑦 ∈ 𝑦)) |
4 | | elequ1 2115 |
. . . . . . 7
⊢ (𝑧 = 𝑦 → (𝑧 ∈ 𝑥 ↔ 𝑦 ∈ 𝑥)) |
5 | | elequ1 2115 |
. . . . . . . . 9
⊢ (𝑧 = 𝑦 → (𝑧 ∈ 𝑧 ↔ 𝑦 ∈ 𝑧)) |
6 | | elequ2 2123 |
. . . . . . . . 9
⊢ (𝑧 = 𝑦 → (𝑦 ∈ 𝑧 ↔ 𝑦 ∈ 𝑦)) |
7 | 5, 6 | bitrd 278 |
. . . . . . . 8
⊢ (𝑧 = 𝑦 → (𝑧 ∈ 𝑧 ↔ 𝑦 ∈ 𝑦)) |
8 | 7 | notbid 317 |
. . . . . . 7
⊢ (𝑧 = 𝑦 → (¬ 𝑧 ∈ 𝑧 ↔ ¬ 𝑦 ∈ 𝑦)) |
9 | 4, 8 | anbi12d 630 |
. . . . . 6
⊢ (𝑧 = 𝑦 → ((𝑧 ∈ 𝑥 ∧ ¬ 𝑧 ∈ 𝑧) ↔ (𝑦 ∈ 𝑥 ∧ ¬ 𝑦 ∈ 𝑦))) |
10 | 3, 9 | bibi12d 345 |
. . . . 5
⊢ (𝑧 = 𝑦 → ((𝑧 ∈ 𝑦 ↔ (𝑧 ∈ 𝑥 ∧ ¬ 𝑧 ∈ 𝑧)) ↔ (𝑦 ∈ 𝑦 ↔ (𝑦 ∈ 𝑥 ∧ ¬ 𝑦 ∈ 𝑦)))) |
11 | 10 | spvv 2001 |
. . . 4
⊢
(∀𝑧(𝑧 ∈ 𝑦 ↔ (𝑧 ∈ 𝑥 ∧ ¬ 𝑧 ∈ 𝑧)) → (𝑦 ∈ 𝑦 ↔ (𝑦 ∈ 𝑥 ∧ ¬ 𝑦 ∈ 𝑦))) |
12 | | pclem6 1022 |
. . . 4
⊢ ((𝑦 ∈ 𝑦 ↔ (𝑦 ∈ 𝑥 ∧ ¬ 𝑦 ∈ 𝑦)) → ¬ 𝑦 ∈ 𝑥) |
13 | 11, 12 | syl 17 |
. . 3
⊢
(∀𝑧(𝑧 ∈ 𝑦 ↔ (𝑧 ∈ 𝑥 ∧ ¬ 𝑧 ∈ 𝑧)) → ¬ 𝑦 ∈ 𝑥) |
14 | 2, 13 | eximii 1840 |
. 2
⊢
∃𝑦 ¬ 𝑦 ∈ 𝑥 |
15 | 1, 14 | mpgbi 1802 |
1
⊢ ¬
∃𝑥∀𝑦 𝑦 ∈ 𝑥 |