| Step | Hyp | Ref
| Expression |
| 1 | | sp 2190 |
. . . . . 6
⊢
(∀𝑦𝜑 → 𝜑) |
| 2 | 1 | imim2i 16 |
. . . . 5
⊢ ((𝑥 ∈ 𝑦 → ∀𝑦𝜑) → (𝑥 ∈ 𝑦 → 𝜑)) |
| 3 | 2 | alimi 1812 |
. . . 4
⊢
(∀𝑥(𝑥 ∈ 𝑦 → ∀𝑦𝜑) → ∀𝑥(𝑥 ∈ 𝑦 → 𝜑)) |
| 4 | 3 | imim1i 63 |
. . 3
⊢
((∀𝑥(𝑥 ∈ 𝑦 → 𝜑) → ∀𝑥(𝑥 = 𝑦 → ∀𝑦𝜑)) → (∀𝑥(𝑥 ∈ 𝑦 → ∀𝑦𝜑) → ∀𝑥(𝑥 = 𝑦 → ∀𝑦𝜑))) |
| 5 | 4 | alimi 1812 |
. 2
⊢
(∀𝑦(∀𝑥(𝑥 ∈ 𝑦 → 𝜑) → ∀𝑥(𝑥 = 𝑦 → ∀𝑦𝜑)) → ∀𝑦(∀𝑥(𝑥 ∈ 𝑦 → ∀𝑦𝜑) → ∀𝑥(𝑥 = 𝑦 → ∀𝑦𝜑))) |
| 6 | | elirrv 9502 |
. . . . . . . 8
⊢ ¬
𝑥 ∈ 𝑥 |
| 7 | | elequ2 2128 |
. . . . . . . 8
⊢ (𝑥 = 𝑦 → (𝑥 ∈ 𝑥 ↔ 𝑥 ∈ 𝑦)) |
| 8 | 6, 7 | mtbii 326 |
. . . . . . 7
⊢ (𝑥 = 𝑦 → ¬ 𝑥 ∈ 𝑦) |
| 9 | 8 | pm2.21d 121 |
. . . . . 6
⊢ (𝑥 = 𝑦 → (𝑥 ∈ 𝑦 → ∀𝑦𝜑)) |
| 10 | 9 | alimi 1812 |
. . . . 5
⊢
(∀𝑥 𝑥 = 𝑦 → ∀𝑥(𝑥 ∈ 𝑦 → ∀𝑦𝜑)) |
| 11 | | sp 2190 |
. . . . . . 7
⊢
(∀𝑥 𝑥 = 𝑦 → 𝑥 = 𝑦) |
| 12 | 1 | a1i 11 |
. . . . . . 7
⊢
(∀𝑥 𝑥 = 𝑦 → (∀𝑦𝜑 → 𝜑)) |
| 13 | 11, 12 | embantd 59 |
. . . . . 6
⊢
(∀𝑥 𝑥 = 𝑦 → ((𝑥 = 𝑦 → ∀𝑦𝜑) → 𝜑)) |
| 14 | 13 | spsd 2194 |
. . . . 5
⊢
(∀𝑥 𝑥 = 𝑦 → (∀𝑥(𝑥 = 𝑦 → ∀𝑦𝜑) → 𝜑)) |
| 15 | 10, 14 | embantd 59 |
. . . 4
⊢
(∀𝑥 𝑥 = 𝑦 → ((∀𝑥(𝑥 ∈ 𝑦 → ∀𝑦𝜑) → ∀𝑥(𝑥 = 𝑦 → ∀𝑦𝜑)) → 𝜑)) |
| 16 | 15 | spsd 2194 |
. . 3
⊢
(∀𝑥 𝑥 = 𝑦 → (∀𝑦(∀𝑥(𝑥 ∈ 𝑦 → ∀𝑦𝜑) → ∀𝑥(𝑥 = 𝑦 → ∀𝑦𝜑)) → 𝜑)) |
| 17 | | nfnae 2438 |
. . . . 5
⊢
Ⅎ𝑦 ¬
∀𝑥 𝑥 = 𝑦 |
| 18 | | nfnae 2438 |
. . . . . . 7
⊢
Ⅎ𝑥 ¬
∀𝑥 𝑥 = 𝑦 |
| 19 | | dveel1 2465 |
. . . . . . . . . 10
⊢ (¬
∀𝑦 𝑦 = 𝑥 → (𝑥 ∈ 𝑧 → ∀𝑦 𝑥 ∈ 𝑧)) |
| 20 | 19 | naecoms 2433 |
. . . . . . . . 9
⊢ (¬
∀𝑥 𝑥 = 𝑦 → (𝑥 ∈ 𝑧 → ∀𝑦 𝑥 ∈ 𝑧)) |
| 21 | 17, 20 | nf5d 2290 |
. . . . . . . 8
⊢ (¬
∀𝑥 𝑥 = 𝑦 → Ⅎ𝑦 𝑥 ∈ 𝑧) |
| 22 | | nfa1 2156 |
. . . . . . . . 9
⊢
Ⅎ𝑦∀𝑦𝜑 |
| 23 | 22 | a1i 11 |
. . . . . . . 8
⊢ (¬
∀𝑥 𝑥 = 𝑦 → Ⅎ𝑦∀𝑦𝜑) |
| 24 | 21, 23 | nfimd 1895 |
. . . . . . 7
⊢ (¬
∀𝑥 𝑥 = 𝑦 → Ⅎ𝑦(𝑥 ∈ 𝑧 → ∀𝑦𝜑)) |
| 25 | 18, 24 | nfald 2333 |
. . . . . 6
⊢ (¬
∀𝑥 𝑥 = 𝑦 → Ⅎ𝑦∀𝑥(𝑥 ∈ 𝑧 → ∀𝑦𝜑)) |
| 26 | | nfeqf1 2383 |
. . . . . . . . 9
⊢ (¬
∀𝑦 𝑦 = 𝑥 → Ⅎ𝑦 𝑥 = 𝑧) |
| 27 | 26 | naecoms 2433 |
. . . . . . . 8
⊢ (¬
∀𝑥 𝑥 = 𝑦 → Ⅎ𝑦 𝑥 = 𝑧) |
| 28 | 27, 23 | nfimd 1895 |
. . . . . . 7
⊢ (¬
∀𝑥 𝑥 = 𝑦 → Ⅎ𝑦(𝑥 = 𝑧 → ∀𝑦𝜑)) |
| 29 | 18, 28 | nfald 2333 |
. . . . . 6
⊢ (¬
∀𝑥 𝑥 = 𝑦 → Ⅎ𝑦∀𝑥(𝑥 = 𝑧 → ∀𝑦𝜑)) |
| 30 | 25, 29 | nfimd 1895 |
. . . . 5
⊢ (¬
∀𝑥 𝑥 = 𝑦 → Ⅎ𝑦(∀𝑥(𝑥 ∈ 𝑧 → ∀𝑦𝜑) → ∀𝑥(𝑥 = 𝑧 → ∀𝑦𝜑))) |
| 31 | | nfeqf2 2381 |
. . . . . . . . 9
⊢ (¬
∀𝑥 𝑥 = 𝑦 → Ⅎ𝑥 𝑧 = 𝑦) |
| 32 | 18, 31 | nfan1 2207 |
. . . . . . . 8
⊢
Ⅎ𝑥(¬
∀𝑥 𝑥 = 𝑦 ∧ 𝑧 = 𝑦) |
| 33 | | elequ2 2128 |
. . . . . . . . . 10
⊢ (𝑧 = 𝑦 → (𝑥 ∈ 𝑧 ↔ 𝑥 ∈ 𝑦)) |
| 34 | 33 | imbi1d 341 |
. . . . . . . . 9
⊢ (𝑧 = 𝑦 → ((𝑥 ∈ 𝑧 → ∀𝑦𝜑) ↔ (𝑥 ∈ 𝑦 → ∀𝑦𝜑))) |
| 35 | 34 | adantl 481 |
. . . . . . . 8
⊢ ((¬
∀𝑥 𝑥 = 𝑦 ∧ 𝑧 = 𝑦) → ((𝑥 ∈ 𝑧 → ∀𝑦𝜑) ↔ (𝑥 ∈ 𝑦 → ∀𝑦𝜑))) |
| 36 | 32, 35 | albid 2229 |
. . . . . . 7
⊢ ((¬
∀𝑥 𝑥 = 𝑦 ∧ 𝑧 = 𝑦) → (∀𝑥(𝑥 ∈ 𝑧 → ∀𝑦𝜑) ↔ ∀𝑥(𝑥 ∈ 𝑦 → ∀𝑦𝜑))) |
| 37 | | equequ2 2027 |
. . . . . . . . . 10
⊢ (𝑧 = 𝑦 → (𝑥 = 𝑧 ↔ 𝑥 = 𝑦)) |
| 38 | 37 | imbi1d 341 |
. . . . . . . . 9
⊢ (𝑧 = 𝑦 → ((𝑥 = 𝑧 → ∀𝑦𝜑) ↔ (𝑥 = 𝑦 → ∀𝑦𝜑))) |
| 39 | 38 | adantl 481 |
. . . . . . . 8
⊢ ((¬
∀𝑥 𝑥 = 𝑦 ∧ 𝑧 = 𝑦) → ((𝑥 = 𝑧 → ∀𝑦𝜑) ↔ (𝑥 = 𝑦 → ∀𝑦𝜑))) |
| 40 | 32, 39 | albid 2229 |
. . . . . . 7
⊢ ((¬
∀𝑥 𝑥 = 𝑦 ∧ 𝑧 = 𝑦) → (∀𝑥(𝑥 = 𝑧 → ∀𝑦𝜑) ↔ ∀𝑥(𝑥 = 𝑦 → ∀𝑦𝜑))) |
| 41 | 36, 40 | imbi12d 344 |
. . . . . 6
⊢ ((¬
∀𝑥 𝑥 = 𝑦 ∧ 𝑧 = 𝑦) → ((∀𝑥(𝑥 ∈ 𝑧 → ∀𝑦𝜑) → ∀𝑥(𝑥 = 𝑧 → ∀𝑦𝜑)) ↔ (∀𝑥(𝑥 ∈ 𝑦 → ∀𝑦𝜑) → ∀𝑥(𝑥 = 𝑦 → ∀𝑦𝜑)))) |
| 42 | 41 | ex 412 |
. . . . 5
⊢ (¬
∀𝑥 𝑥 = 𝑦 → (𝑧 = 𝑦 → ((∀𝑥(𝑥 ∈ 𝑧 → ∀𝑦𝜑) → ∀𝑥(𝑥 = 𝑧 → ∀𝑦𝜑)) ↔ (∀𝑥(𝑥 ∈ 𝑦 → ∀𝑦𝜑) → ∀𝑥(𝑥 = 𝑦 → ∀𝑦𝜑))))) |
| 43 | 17, 30, 42 | cbvaldw 2342 |
. . . 4
⊢ (¬
∀𝑥 𝑥 = 𝑦 → (∀𝑧(∀𝑥(𝑥 ∈ 𝑧 → ∀𝑦𝜑) → ∀𝑥(𝑥 = 𝑧 → ∀𝑦𝜑)) ↔ ∀𝑦(∀𝑥(𝑥 ∈ 𝑦 → ∀𝑦𝜑) → ∀𝑥(𝑥 = 𝑦 → ∀𝑦𝜑)))) |
| 44 | | mh-setind 36666 |
. . . . 5
⊢
(∀𝑧(∀𝑥(𝑥 ∈ 𝑧 → ∀𝑦𝜑) → ∀𝑥(𝑥 = 𝑧 → ∀𝑦𝜑)) → ∀𝑦𝜑) |
| 45 | 44 | 19.21bi 2196 |
. . . 4
⊢
(∀𝑧(∀𝑥(𝑥 ∈ 𝑧 → ∀𝑦𝜑) → ∀𝑥(𝑥 = 𝑧 → ∀𝑦𝜑)) → 𝜑) |
| 46 | 43, 45 | biimtrrdi 254 |
. . 3
⊢ (¬
∀𝑥 𝑥 = 𝑦 → (∀𝑦(∀𝑥(𝑥 ∈ 𝑦 → ∀𝑦𝜑) → ∀𝑥(𝑥 = 𝑦 → ∀𝑦𝜑)) → 𝜑)) |
| 47 | 16, 46 | pm2.61i 182 |
. 2
⊢
(∀𝑦(∀𝑥(𝑥 ∈ 𝑦 → ∀𝑦𝜑) → ∀𝑥(𝑥 = 𝑦 → ∀𝑦𝜑)) → 𝜑) |
| 48 | 5, 47 | syl 17 |
1
⊢
(∀𝑦(∀𝑥(𝑥 ∈ 𝑦 → 𝜑) → ∀𝑥(𝑥 = 𝑦 → ∀𝑦𝜑)) → 𝜑) |