| Step | Hyp | Ref | Expression | 
|---|
| 1 |  | axpowndlem3 10640 | . . . . 5
⊢ (¬
𝑥 = 𝑤 → ∃𝑥∀𝑤(∀𝑥(∃𝑧 𝑥 ∈ 𝑤 → ∀𝑤 𝑥 ∈ 𝑧) → 𝑤 ∈ 𝑥)) | 
| 2 | 1 | ax-gen 1794 | . . . 4
⊢
∀𝑤(¬
𝑥 = 𝑤 → ∃𝑥∀𝑤(∀𝑥(∃𝑧 𝑥 ∈ 𝑤 → ∀𝑤 𝑥 ∈ 𝑧) → 𝑤 ∈ 𝑥)) | 
| 3 |  | nfnae 2438 | . . . . . 6
⊢
Ⅎ𝑦 ¬
∀𝑦 𝑦 = 𝑥 | 
| 4 |  | nfnae 2438 | . . . . . 6
⊢
Ⅎ𝑦 ¬
∀𝑦 𝑦 = 𝑧 | 
| 5 | 3, 4 | nfan 1898 | . . . . 5
⊢
Ⅎ𝑦(¬
∀𝑦 𝑦 = 𝑥 ∧ ¬ ∀𝑦 𝑦 = 𝑧) | 
| 6 |  | nfcvf 2931 | . . . . . . . . 9
⊢ (¬
∀𝑦 𝑦 = 𝑥 → Ⅎ𝑦𝑥) | 
| 7 | 6 | adantr 480 | . . . . . . . 8
⊢ ((¬
∀𝑦 𝑦 = 𝑥 ∧ ¬ ∀𝑦 𝑦 = 𝑧) → Ⅎ𝑦𝑥) | 
| 8 |  | nfcvd 2905 | . . . . . . . 8
⊢ ((¬
∀𝑦 𝑦 = 𝑥 ∧ ¬ ∀𝑦 𝑦 = 𝑧) → Ⅎ𝑦𝑤) | 
| 9 | 7, 8 | nfeqd 2915 | . . . . . . 7
⊢ ((¬
∀𝑦 𝑦 = 𝑥 ∧ ¬ ∀𝑦 𝑦 = 𝑧) → Ⅎ𝑦 𝑥 = 𝑤) | 
| 10 | 9 | nfnd 1857 | . . . . . 6
⊢ ((¬
∀𝑦 𝑦 = 𝑥 ∧ ¬ ∀𝑦 𝑦 = 𝑧) → Ⅎ𝑦 ¬ 𝑥 = 𝑤) | 
| 11 |  | nfnae 2438 | . . . . . . . 8
⊢
Ⅎ𝑥 ¬
∀𝑦 𝑦 = 𝑥 | 
| 12 |  | nfnae 2438 | . . . . . . . 8
⊢
Ⅎ𝑥 ¬
∀𝑦 𝑦 = 𝑧 | 
| 13 | 11, 12 | nfan 1898 | . . . . . . 7
⊢
Ⅎ𝑥(¬
∀𝑦 𝑦 = 𝑥 ∧ ¬ ∀𝑦 𝑦 = 𝑧) | 
| 14 |  | nfv 1913 | . . . . . . . 8
⊢
Ⅎ𝑤(¬
∀𝑦 𝑦 = 𝑥 ∧ ¬ ∀𝑦 𝑦 = 𝑧) | 
| 15 |  | nfnae 2438 | . . . . . . . . . . . . 13
⊢
Ⅎ𝑧 ¬
∀𝑦 𝑦 = 𝑥 | 
| 16 |  | nfnae 2438 | . . . . . . . . . . . . 13
⊢
Ⅎ𝑧 ¬
∀𝑦 𝑦 = 𝑧 | 
| 17 | 15, 16 | nfan 1898 | . . . . . . . . . . . 12
⊢
Ⅎ𝑧(¬
∀𝑦 𝑦 = 𝑥 ∧ ¬ ∀𝑦 𝑦 = 𝑧) | 
| 18 | 7, 8 | nfeld 2916 | . . . . . . . . . . . 12
⊢ ((¬
∀𝑦 𝑦 = 𝑥 ∧ ¬ ∀𝑦 𝑦 = 𝑧) → Ⅎ𝑦 𝑥 ∈ 𝑤) | 
| 19 | 17, 18 | nfexd 2328 | . . . . . . . . . . 11
⊢ ((¬
∀𝑦 𝑦 = 𝑥 ∧ ¬ ∀𝑦 𝑦 = 𝑧) → Ⅎ𝑦∃𝑧 𝑥 ∈ 𝑤) | 
| 20 |  | nfcvf 2931 | . . . . . . . . . . . . . 14
⊢ (¬
∀𝑦 𝑦 = 𝑧 → Ⅎ𝑦𝑧) | 
| 21 | 20 | adantl 481 | . . . . . . . . . . . . 13
⊢ ((¬
∀𝑦 𝑦 = 𝑥 ∧ ¬ ∀𝑦 𝑦 = 𝑧) → Ⅎ𝑦𝑧) | 
| 22 | 7, 21 | nfeld 2916 | . . . . . . . . . . . 12
⊢ ((¬
∀𝑦 𝑦 = 𝑥 ∧ ¬ ∀𝑦 𝑦 = 𝑧) → Ⅎ𝑦 𝑥 ∈ 𝑧) | 
| 23 | 14, 22 | nfald 2327 | . . . . . . . . . . 11
⊢ ((¬
∀𝑦 𝑦 = 𝑥 ∧ ¬ ∀𝑦 𝑦 = 𝑧) → Ⅎ𝑦∀𝑤 𝑥 ∈ 𝑧) | 
| 24 | 19, 23 | nfimd 1893 | . . . . . . . . . 10
⊢ ((¬
∀𝑦 𝑦 = 𝑥 ∧ ¬ ∀𝑦 𝑦 = 𝑧) → Ⅎ𝑦(∃𝑧 𝑥 ∈ 𝑤 → ∀𝑤 𝑥 ∈ 𝑧)) | 
| 25 | 13, 24 | nfald 2327 | . . . . . . . . 9
⊢ ((¬
∀𝑦 𝑦 = 𝑥 ∧ ¬ ∀𝑦 𝑦 = 𝑧) → Ⅎ𝑦∀𝑥(∃𝑧 𝑥 ∈ 𝑤 → ∀𝑤 𝑥 ∈ 𝑧)) | 
| 26 | 8, 7 | nfeld 2916 | . . . . . . . . 9
⊢ ((¬
∀𝑦 𝑦 = 𝑥 ∧ ¬ ∀𝑦 𝑦 = 𝑧) → Ⅎ𝑦 𝑤 ∈ 𝑥) | 
| 27 | 25, 26 | nfimd 1893 | . . . . . . . 8
⊢ ((¬
∀𝑦 𝑦 = 𝑥 ∧ ¬ ∀𝑦 𝑦 = 𝑧) → Ⅎ𝑦(∀𝑥(∃𝑧 𝑥 ∈ 𝑤 → ∀𝑤 𝑥 ∈ 𝑧) → 𝑤 ∈ 𝑥)) | 
| 28 | 14, 27 | nfald 2327 | . . . . . . 7
⊢ ((¬
∀𝑦 𝑦 = 𝑥 ∧ ¬ ∀𝑦 𝑦 = 𝑧) → Ⅎ𝑦∀𝑤(∀𝑥(∃𝑧 𝑥 ∈ 𝑤 → ∀𝑤 𝑥 ∈ 𝑧) → 𝑤 ∈ 𝑥)) | 
| 29 | 13, 28 | nfexd 2328 | . . . . . 6
⊢ ((¬
∀𝑦 𝑦 = 𝑥 ∧ ¬ ∀𝑦 𝑦 = 𝑧) → Ⅎ𝑦∃𝑥∀𝑤(∀𝑥(∃𝑧 𝑥 ∈ 𝑤 → ∀𝑤 𝑥 ∈ 𝑧) → 𝑤 ∈ 𝑥)) | 
| 30 | 10, 29 | nfimd 1893 | . . . . 5
⊢ ((¬
∀𝑦 𝑦 = 𝑥 ∧ ¬ ∀𝑦 𝑦 = 𝑧) → Ⅎ𝑦(¬ 𝑥 = 𝑤 → ∃𝑥∀𝑤(∀𝑥(∃𝑧 𝑥 ∈ 𝑤 → ∀𝑤 𝑥 ∈ 𝑧) → 𝑤 ∈ 𝑥))) | 
| 31 |  | equequ2 2024 | . . . . . . . . 9
⊢ (𝑤 = 𝑦 → (𝑥 = 𝑤 ↔ 𝑥 = 𝑦)) | 
| 32 | 31 | notbid 318 | . . . . . . . 8
⊢ (𝑤 = 𝑦 → (¬ 𝑥 = 𝑤 ↔ ¬ 𝑥 = 𝑦)) | 
| 33 | 32 | adantl 481 | . . . . . . 7
⊢ (((¬
∀𝑦 𝑦 = 𝑥 ∧ ¬ ∀𝑦 𝑦 = 𝑧) ∧ 𝑤 = 𝑦) → (¬ 𝑥 = 𝑤 ↔ ¬ 𝑥 = 𝑦)) | 
| 34 |  | nfcvd 2905 | . . . . . . . . . . . . . . 15
⊢ ((¬
∀𝑦 𝑦 = 𝑥 ∧ ¬ ∀𝑦 𝑦 = 𝑧) → Ⅎ𝑥𝑤) | 
| 35 |  | nfcvf2 2932 | . . . . . . . . . . . . . . . 16
⊢ (¬
∀𝑦 𝑦 = 𝑥 → Ⅎ𝑥𝑦) | 
| 36 | 35 | adantr 480 | . . . . . . . . . . . . . . 15
⊢ ((¬
∀𝑦 𝑦 = 𝑥 ∧ ¬ ∀𝑦 𝑦 = 𝑧) → Ⅎ𝑥𝑦) | 
| 37 | 34, 36 | nfeqd 2915 | . . . . . . . . . . . . . 14
⊢ ((¬
∀𝑦 𝑦 = 𝑥 ∧ ¬ ∀𝑦 𝑦 = 𝑧) → Ⅎ𝑥 𝑤 = 𝑦) | 
| 38 | 13, 37 | nfan1 2199 | . . . . . . . . . . . . 13
⊢
Ⅎ𝑥((¬
∀𝑦 𝑦 = 𝑥 ∧ ¬ ∀𝑦 𝑦 = 𝑧) ∧ 𝑤 = 𝑦) | 
| 39 |  | nfcvd 2905 | . . . . . . . . . . . . . . . . 17
⊢ ((¬
∀𝑦 𝑦 = 𝑥 ∧ ¬ ∀𝑦 𝑦 = 𝑧) → Ⅎ𝑧𝑤) | 
| 40 |  | nfcvf2 2932 | . . . . . . . . . . . . . . . . . 18
⊢ (¬
∀𝑦 𝑦 = 𝑧 → Ⅎ𝑧𝑦) | 
| 41 | 40 | adantl 481 | . . . . . . . . . . . . . . . . 17
⊢ ((¬
∀𝑦 𝑦 = 𝑥 ∧ ¬ ∀𝑦 𝑦 = 𝑧) → Ⅎ𝑧𝑦) | 
| 42 | 39, 41 | nfeqd 2915 | . . . . . . . . . . . . . . . 16
⊢ ((¬
∀𝑦 𝑦 = 𝑥 ∧ ¬ ∀𝑦 𝑦 = 𝑧) → Ⅎ𝑧 𝑤 = 𝑦) | 
| 43 | 17, 42 | nfan1 2199 | . . . . . . . . . . . . . . 15
⊢
Ⅎ𝑧((¬
∀𝑦 𝑦 = 𝑥 ∧ ¬ ∀𝑦 𝑦 = 𝑧) ∧ 𝑤 = 𝑦) | 
| 44 |  | elequ2 2122 | . . . . . . . . . . . . . . . 16
⊢ (𝑤 = 𝑦 → (𝑥 ∈ 𝑤 ↔ 𝑥 ∈ 𝑦)) | 
| 45 | 44 | adantl 481 | . . . . . . . . . . . . . . 15
⊢ (((¬
∀𝑦 𝑦 = 𝑥 ∧ ¬ ∀𝑦 𝑦 = 𝑧) ∧ 𝑤 = 𝑦) → (𝑥 ∈ 𝑤 ↔ 𝑥 ∈ 𝑦)) | 
| 46 | 43, 45 | exbid 2222 | . . . . . . . . . . . . . 14
⊢ (((¬
∀𝑦 𝑦 = 𝑥 ∧ ¬ ∀𝑦 𝑦 = 𝑧) ∧ 𝑤 = 𝑦) → (∃𝑧 𝑥 ∈ 𝑤 ↔ ∃𝑧 𝑥 ∈ 𝑦)) | 
| 47 |  | biidd 262 | . . . . . . . . . . . . . . . . 17
⊢ (𝑤 = 𝑦 → (𝑥 ∈ 𝑧 ↔ 𝑥 ∈ 𝑧)) | 
| 48 | 47 | a1i 11 | . . . . . . . . . . . . . . . 16
⊢ ((¬
∀𝑦 𝑦 = 𝑥 ∧ ¬ ∀𝑦 𝑦 = 𝑧) → (𝑤 = 𝑦 → (𝑥 ∈ 𝑧 ↔ 𝑥 ∈ 𝑧))) | 
| 49 | 5, 22, 48 | cbvald 2411 | . . . . . . . . . . . . . . 15
⊢ ((¬
∀𝑦 𝑦 = 𝑥 ∧ ¬ ∀𝑦 𝑦 = 𝑧) → (∀𝑤 𝑥 ∈ 𝑧 ↔ ∀𝑦 𝑥 ∈ 𝑧)) | 
| 50 | 49 | adantr 480 | . . . . . . . . . . . . . 14
⊢ (((¬
∀𝑦 𝑦 = 𝑥 ∧ ¬ ∀𝑦 𝑦 = 𝑧) ∧ 𝑤 = 𝑦) → (∀𝑤 𝑥 ∈ 𝑧 ↔ ∀𝑦 𝑥 ∈ 𝑧)) | 
| 51 | 46, 50 | imbi12d 344 | . . . . . . . . . . . . 13
⊢ (((¬
∀𝑦 𝑦 = 𝑥 ∧ ¬ ∀𝑦 𝑦 = 𝑧) ∧ 𝑤 = 𝑦) → ((∃𝑧 𝑥 ∈ 𝑤 → ∀𝑤 𝑥 ∈ 𝑧) ↔ (∃𝑧 𝑥 ∈ 𝑦 → ∀𝑦 𝑥 ∈ 𝑧))) | 
| 52 | 38, 51 | albid 2221 | . . . . . . . . . . . 12
⊢ (((¬
∀𝑦 𝑦 = 𝑥 ∧ ¬ ∀𝑦 𝑦 = 𝑧) ∧ 𝑤 = 𝑦) → (∀𝑥(∃𝑧 𝑥 ∈ 𝑤 → ∀𝑤 𝑥 ∈ 𝑧) ↔ ∀𝑥(∃𝑧 𝑥 ∈ 𝑦 → ∀𝑦 𝑥 ∈ 𝑧))) | 
| 53 |  | elequ1 2114 | . . . . . . . . . . . . 13
⊢ (𝑤 = 𝑦 → (𝑤 ∈ 𝑥 ↔ 𝑦 ∈ 𝑥)) | 
| 54 | 53 | adantl 481 | . . . . . . . . . . . 12
⊢ (((¬
∀𝑦 𝑦 = 𝑥 ∧ ¬ ∀𝑦 𝑦 = 𝑧) ∧ 𝑤 = 𝑦) → (𝑤 ∈ 𝑥 ↔ 𝑦 ∈ 𝑥)) | 
| 55 | 52, 54 | imbi12d 344 | . . . . . . . . . . 11
⊢ (((¬
∀𝑦 𝑦 = 𝑥 ∧ ¬ ∀𝑦 𝑦 = 𝑧) ∧ 𝑤 = 𝑦) → ((∀𝑥(∃𝑧 𝑥 ∈ 𝑤 → ∀𝑤 𝑥 ∈ 𝑧) → 𝑤 ∈ 𝑥) ↔ (∀𝑥(∃𝑧 𝑥 ∈ 𝑦 → ∀𝑦 𝑥 ∈ 𝑧) → 𝑦 ∈ 𝑥))) | 
| 56 | 55 | ex 412 | . . . . . . . . . 10
⊢ ((¬
∀𝑦 𝑦 = 𝑥 ∧ ¬ ∀𝑦 𝑦 = 𝑧) → (𝑤 = 𝑦 → ((∀𝑥(∃𝑧 𝑥 ∈ 𝑤 → ∀𝑤 𝑥 ∈ 𝑧) → 𝑤 ∈ 𝑥) ↔ (∀𝑥(∃𝑧 𝑥 ∈ 𝑦 → ∀𝑦 𝑥 ∈ 𝑧) → 𝑦 ∈ 𝑥)))) | 
| 57 | 5, 27, 56 | cbvald 2411 | . . . . . . . . 9
⊢ ((¬
∀𝑦 𝑦 = 𝑥 ∧ ¬ ∀𝑦 𝑦 = 𝑧) → (∀𝑤(∀𝑥(∃𝑧 𝑥 ∈ 𝑤 → ∀𝑤 𝑥 ∈ 𝑧) → 𝑤 ∈ 𝑥) ↔ ∀𝑦(∀𝑥(∃𝑧 𝑥 ∈ 𝑦 → ∀𝑦 𝑥 ∈ 𝑧) → 𝑦 ∈ 𝑥))) | 
| 58 | 13, 57 | exbid 2222 | . . . . . . . 8
⊢ ((¬
∀𝑦 𝑦 = 𝑥 ∧ ¬ ∀𝑦 𝑦 = 𝑧) → (∃𝑥∀𝑤(∀𝑥(∃𝑧 𝑥 ∈ 𝑤 → ∀𝑤 𝑥 ∈ 𝑧) → 𝑤 ∈ 𝑥) ↔ ∃𝑥∀𝑦(∀𝑥(∃𝑧 𝑥 ∈ 𝑦 → ∀𝑦 𝑥 ∈ 𝑧) → 𝑦 ∈ 𝑥))) | 
| 59 | 58 | adantr 480 | . . . . . . 7
⊢ (((¬
∀𝑦 𝑦 = 𝑥 ∧ ¬ ∀𝑦 𝑦 = 𝑧) ∧ 𝑤 = 𝑦) → (∃𝑥∀𝑤(∀𝑥(∃𝑧 𝑥 ∈ 𝑤 → ∀𝑤 𝑥 ∈ 𝑧) → 𝑤 ∈ 𝑥) ↔ ∃𝑥∀𝑦(∀𝑥(∃𝑧 𝑥 ∈ 𝑦 → ∀𝑦 𝑥 ∈ 𝑧) → 𝑦 ∈ 𝑥))) | 
| 60 | 33, 59 | imbi12d 344 | . . . . . 6
⊢ (((¬
∀𝑦 𝑦 = 𝑥 ∧ ¬ ∀𝑦 𝑦 = 𝑧) ∧ 𝑤 = 𝑦) → ((¬ 𝑥 = 𝑤 → ∃𝑥∀𝑤(∀𝑥(∃𝑧 𝑥 ∈ 𝑤 → ∀𝑤 𝑥 ∈ 𝑧) → 𝑤 ∈ 𝑥)) ↔ (¬ 𝑥 = 𝑦 → ∃𝑥∀𝑦(∀𝑥(∃𝑧 𝑥 ∈ 𝑦 → ∀𝑦 𝑥 ∈ 𝑧) → 𝑦 ∈ 𝑥)))) | 
| 61 | 60 | ex 412 | . . . . 5
⊢ ((¬
∀𝑦 𝑦 = 𝑥 ∧ ¬ ∀𝑦 𝑦 = 𝑧) → (𝑤 = 𝑦 → ((¬ 𝑥 = 𝑤 → ∃𝑥∀𝑤(∀𝑥(∃𝑧 𝑥 ∈ 𝑤 → ∀𝑤 𝑥 ∈ 𝑧) → 𝑤 ∈ 𝑥)) ↔ (¬ 𝑥 = 𝑦 → ∃𝑥∀𝑦(∀𝑥(∃𝑧 𝑥 ∈ 𝑦 → ∀𝑦 𝑥 ∈ 𝑧) → 𝑦 ∈ 𝑥))))) | 
| 62 | 5, 30, 61 | cbvald 2411 | . . . 4
⊢ ((¬
∀𝑦 𝑦 = 𝑥 ∧ ¬ ∀𝑦 𝑦 = 𝑧) → (∀𝑤(¬ 𝑥 = 𝑤 → ∃𝑥∀𝑤(∀𝑥(∃𝑧 𝑥 ∈ 𝑤 → ∀𝑤 𝑥 ∈ 𝑧) → 𝑤 ∈ 𝑥)) ↔ ∀𝑦(¬ 𝑥 = 𝑦 → ∃𝑥∀𝑦(∀𝑥(∃𝑧 𝑥 ∈ 𝑦 → ∀𝑦 𝑥 ∈ 𝑧) → 𝑦 ∈ 𝑥)))) | 
| 63 | 2, 62 | mpbii 233 | . . 3
⊢ ((¬
∀𝑦 𝑦 = 𝑥 ∧ ¬ ∀𝑦 𝑦 = 𝑧) → ∀𝑦(¬ 𝑥 = 𝑦 → ∃𝑥∀𝑦(∀𝑥(∃𝑧 𝑥 ∈ 𝑦 → ∀𝑦 𝑥 ∈ 𝑧) → 𝑦 ∈ 𝑥))) | 
| 64 | 63 | 19.21bi 2188 | . 2
⊢ ((¬
∀𝑦 𝑦 = 𝑥 ∧ ¬ ∀𝑦 𝑦 = 𝑧) → (¬ 𝑥 = 𝑦 → ∃𝑥∀𝑦(∀𝑥(∃𝑧 𝑥 ∈ 𝑦 → ∀𝑦 𝑥 ∈ 𝑧) → 𝑦 ∈ 𝑥))) | 
| 65 | 64 | ex 412 | 1
⊢ (¬
∀𝑦 𝑦 = 𝑥 → (¬ ∀𝑦 𝑦 = 𝑧 → (¬ 𝑥 = 𝑦 → ∃𝑥∀𝑦(∀𝑥(∃𝑧 𝑥 ∈ 𝑦 → ∀𝑦 𝑥 ∈ 𝑧) → 𝑦 ∈ 𝑥)))) |