| Step | Hyp | Ref | Expression | 
|---|
| 1 |  | zfac 10500 | . . . 4
⊢
∃𝑣∀𝑦∀𝑧((𝑦 ∈ 𝑧 ∧ 𝑧 ∈ 𝑤) → ∃𝑤∀𝑦(∃𝑤((𝑦 ∈ 𝑧 ∧ 𝑧 ∈ 𝑤) ∧ (𝑦 ∈ 𝑤 ∧ 𝑤 ∈ 𝑣)) ↔ 𝑦 = 𝑤)) | 
| 2 |  | nfnae 2439 | . . . . . 6
⊢
Ⅎ𝑥 ¬
∀𝑥 𝑥 = 𝑧 | 
| 3 |  | nfnae 2439 | . . . . . 6
⊢
Ⅎ𝑥 ¬
∀𝑥 𝑥 = 𝑦 | 
| 4 |  | nfnae 2439 | . . . . . 6
⊢
Ⅎ𝑥 ¬
∀𝑥 𝑥 = 𝑤 | 
| 5 | 2, 3, 4 | nf3an 1901 | . . . . 5
⊢
Ⅎ𝑥(¬
∀𝑥 𝑥 = 𝑧 ∧ ¬ ∀𝑥 𝑥 = 𝑦 ∧ ¬ ∀𝑥 𝑥 = 𝑤) | 
| 6 |  | nfnae 2439 | . . . . . . 7
⊢
Ⅎ𝑦 ¬
∀𝑥 𝑥 = 𝑧 | 
| 7 |  | nfnae 2439 | . . . . . . 7
⊢
Ⅎ𝑦 ¬
∀𝑥 𝑥 = 𝑦 | 
| 8 |  | nfnae 2439 | . . . . . . 7
⊢
Ⅎ𝑦 ¬
∀𝑥 𝑥 = 𝑤 | 
| 9 | 6, 7, 8 | nf3an 1901 | . . . . . 6
⊢
Ⅎ𝑦(¬
∀𝑥 𝑥 = 𝑧 ∧ ¬ ∀𝑥 𝑥 = 𝑦 ∧ ¬ ∀𝑥 𝑥 = 𝑤) | 
| 10 |  | nfnae 2439 | . . . . . . . 8
⊢
Ⅎ𝑧 ¬
∀𝑥 𝑥 = 𝑧 | 
| 11 |  | nfnae 2439 | . . . . . . . 8
⊢
Ⅎ𝑧 ¬
∀𝑥 𝑥 = 𝑦 | 
| 12 |  | nfnae 2439 | . . . . . . . 8
⊢
Ⅎ𝑧 ¬
∀𝑥 𝑥 = 𝑤 | 
| 13 | 10, 11, 12 | nf3an 1901 | . . . . . . 7
⊢
Ⅎ𝑧(¬
∀𝑥 𝑥 = 𝑧 ∧ ¬ ∀𝑥 𝑥 = 𝑦 ∧ ¬ ∀𝑥 𝑥 = 𝑤) | 
| 14 |  | nfcvf 2932 | . . . . . . . . . . 11
⊢ (¬
∀𝑥 𝑥 = 𝑦 → Ⅎ𝑥𝑦) | 
| 15 | 14 | 3ad2ant2 1135 | . . . . . . . . . 10
⊢ ((¬
∀𝑥 𝑥 = 𝑧 ∧ ¬ ∀𝑥 𝑥 = 𝑦 ∧ ¬ ∀𝑥 𝑥 = 𝑤) → Ⅎ𝑥𝑦) | 
| 16 |  | nfcvf 2932 | . . . . . . . . . . 11
⊢ (¬
∀𝑥 𝑥 = 𝑧 → Ⅎ𝑥𝑧) | 
| 17 | 16 | 3ad2ant1 1134 | . . . . . . . . . 10
⊢ ((¬
∀𝑥 𝑥 = 𝑧 ∧ ¬ ∀𝑥 𝑥 = 𝑦 ∧ ¬ ∀𝑥 𝑥 = 𝑤) → Ⅎ𝑥𝑧) | 
| 18 | 15, 17 | nfeld 2917 | . . . . . . . . 9
⊢ ((¬
∀𝑥 𝑥 = 𝑧 ∧ ¬ ∀𝑥 𝑥 = 𝑦 ∧ ¬ ∀𝑥 𝑥 = 𝑤) → Ⅎ𝑥 𝑦 ∈ 𝑧) | 
| 19 |  | nfcvf 2932 | . . . . . . . . . . 11
⊢ (¬
∀𝑥 𝑥 = 𝑤 → Ⅎ𝑥𝑤) | 
| 20 | 19 | 3ad2ant3 1136 | . . . . . . . . . 10
⊢ ((¬
∀𝑥 𝑥 = 𝑧 ∧ ¬ ∀𝑥 𝑥 = 𝑦 ∧ ¬ ∀𝑥 𝑥 = 𝑤) → Ⅎ𝑥𝑤) | 
| 21 | 17, 20 | nfeld 2917 | . . . . . . . . 9
⊢ ((¬
∀𝑥 𝑥 = 𝑧 ∧ ¬ ∀𝑥 𝑥 = 𝑦 ∧ ¬ ∀𝑥 𝑥 = 𝑤) → Ⅎ𝑥 𝑧 ∈ 𝑤) | 
| 22 | 18, 21 | nfand 1897 | . . . . . . . 8
⊢ ((¬
∀𝑥 𝑥 = 𝑧 ∧ ¬ ∀𝑥 𝑥 = 𝑦 ∧ ¬ ∀𝑥 𝑥 = 𝑤) → Ⅎ𝑥(𝑦 ∈ 𝑧 ∧ 𝑧 ∈ 𝑤)) | 
| 23 |  | nfnae 2439 | . . . . . . . . . 10
⊢
Ⅎ𝑤 ¬
∀𝑥 𝑥 = 𝑧 | 
| 24 |  | nfnae 2439 | . . . . . . . . . 10
⊢
Ⅎ𝑤 ¬
∀𝑥 𝑥 = 𝑦 | 
| 25 |  | nfnae 2439 | . . . . . . . . . 10
⊢
Ⅎ𝑤 ¬
∀𝑥 𝑥 = 𝑤 | 
| 26 | 23, 24, 25 | nf3an 1901 | . . . . . . . . 9
⊢
Ⅎ𝑤(¬
∀𝑥 𝑥 = 𝑧 ∧ ¬ ∀𝑥 𝑥 = 𝑦 ∧ ¬ ∀𝑥 𝑥 = 𝑤) | 
| 27 | 15, 20 | nfeld 2917 | . . . . . . . . . . . . . 14
⊢ ((¬
∀𝑥 𝑥 = 𝑧 ∧ ¬ ∀𝑥 𝑥 = 𝑦 ∧ ¬ ∀𝑥 𝑥 = 𝑤) → Ⅎ𝑥 𝑦 ∈ 𝑤) | 
| 28 |  | nfcvd 2906 | . . . . . . . . . . . . . . 15
⊢ ((¬
∀𝑥 𝑥 = 𝑧 ∧ ¬ ∀𝑥 𝑥 = 𝑦 ∧ ¬ ∀𝑥 𝑥 = 𝑤) → Ⅎ𝑥𝑣) | 
| 29 | 20, 28 | nfeld 2917 | . . . . . . . . . . . . . 14
⊢ ((¬
∀𝑥 𝑥 = 𝑧 ∧ ¬ ∀𝑥 𝑥 = 𝑦 ∧ ¬ ∀𝑥 𝑥 = 𝑤) → Ⅎ𝑥 𝑤 ∈ 𝑣) | 
| 30 | 27, 29 | nfand 1897 | . . . . . . . . . . . . 13
⊢ ((¬
∀𝑥 𝑥 = 𝑧 ∧ ¬ ∀𝑥 𝑥 = 𝑦 ∧ ¬ ∀𝑥 𝑥 = 𝑤) → Ⅎ𝑥(𝑦 ∈ 𝑤 ∧ 𝑤 ∈ 𝑣)) | 
| 31 | 22, 30 | nfand 1897 | . . . . . . . . . . . 12
⊢ ((¬
∀𝑥 𝑥 = 𝑧 ∧ ¬ ∀𝑥 𝑥 = 𝑦 ∧ ¬ ∀𝑥 𝑥 = 𝑤) → Ⅎ𝑥((𝑦 ∈ 𝑧 ∧ 𝑧 ∈ 𝑤) ∧ (𝑦 ∈ 𝑤 ∧ 𝑤 ∈ 𝑣))) | 
| 32 | 26, 31 | nfexd 2329 | . . . . . . . . . . 11
⊢ ((¬
∀𝑥 𝑥 = 𝑧 ∧ ¬ ∀𝑥 𝑥 = 𝑦 ∧ ¬ ∀𝑥 𝑥 = 𝑤) → Ⅎ𝑥∃𝑤((𝑦 ∈ 𝑧 ∧ 𝑧 ∈ 𝑤) ∧ (𝑦 ∈ 𝑤 ∧ 𝑤 ∈ 𝑣))) | 
| 33 | 15, 20 | nfeqd 2916 | . . . . . . . . . . 11
⊢ ((¬
∀𝑥 𝑥 = 𝑧 ∧ ¬ ∀𝑥 𝑥 = 𝑦 ∧ ¬ ∀𝑥 𝑥 = 𝑤) → Ⅎ𝑥 𝑦 = 𝑤) | 
| 34 | 32, 33 | nfbid 1902 | . . . . . . . . . 10
⊢ ((¬
∀𝑥 𝑥 = 𝑧 ∧ ¬ ∀𝑥 𝑥 = 𝑦 ∧ ¬ ∀𝑥 𝑥 = 𝑤) → Ⅎ𝑥(∃𝑤((𝑦 ∈ 𝑧 ∧ 𝑧 ∈ 𝑤) ∧ (𝑦 ∈ 𝑤 ∧ 𝑤 ∈ 𝑣)) ↔ 𝑦 = 𝑤)) | 
| 35 | 9, 34 | nfald 2328 | . . . . . . . . 9
⊢ ((¬
∀𝑥 𝑥 = 𝑧 ∧ ¬ ∀𝑥 𝑥 = 𝑦 ∧ ¬ ∀𝑥 𝑥 = 𝑤) → Ⅎ𝑥∀𝑦(∃𝑤((𝑦 ∈ 𝑧 ∧ 𝑧 ∈ 𝑤) ∧ (𝑦 ∈ 𝑤 ∧ 𝑤 ∈ 𝑣)) ↔ 𝑦 = 𝑤)) | 
| 36 | 26, 35 | nfexd 2329 | . . . . . . . 8
⊢ ((¬
∀𝑥 𝑥 = 𝑧 ∧ ¬ ∀𝑥 𝑥 = 𝑦 ∧ ¬ ∀𝑥 𝑥 = 𝑤) → Ⅎ𝑥∃𝑤∀𝑦(∃𝑤((𝑦 ∈ 𝑧 ∧ 𝑧 ∈ 𝑤) ∧ (𝑦 ∈ 𝑤 ∧ 𝑤 ∈ 𝑣)) ↔ 𝑦 = 𝑤)) | 
| 37 | 22, 36 | nfimd 1894 | . . . . . . 7
⊢ ((¬
∀𝑥 𝑥 = 𝑧 ∧ ¬ ∀𝑥 𝑥 = 𝑦 ∧ ¬ ∀𝑥 𝑥 = 𝑤) → Ⅎ𝑥((𝑦 ∈ 𝑧 ∧ 𝑧 ∈ 𝑤) → ∃𝑤∀𝑦(∃𝑤((𝑦 ∈ 𝑧 ∧ 𝑧 ∈ 𝑤) ∧ (𝑦 ∈ 𝑤 ∧ 𝑤 ∈ 𝑣)) ↔ 𝑦 = 𝑤))) | 
| 38 | 13, 37 | nfald 2328 | . . . . . 6
⊢ ((¬
∀𝑥 𝑥 = 𝑧 ∧ ¬ ∀𝑥 𝑥 = 𝑦 ∧ ¬ ∀𝑥 𝑥 = 𝑤) → Ⅎ𝑥∀𝑧((𝑦 ∈ 𝑧 ∧ 𝑧 ∈ 𝑤) → ∃𝑤∀𝑦(∃𝑤((𝑦 ∈ 𝑧 ∧ 𝑧 ∈ 𝑤) ∧ (𝑦 ∈ 𝑤 ∧ 𝑤 ∈ 𝑣)) ↔ 𝑦 = 𝑤))) | 
| 39 | 9, 38 | nfald 2328 | . . . . 5
⊢ ((¬
∀𝑥 𝑥 = 𝑧 ∧ ¬ ∀𝑥 𝑥 = 𝑦 ∧ ¬ ∀𝑥 𝑥 = 𝑤) → Ⅎ𝑥∀𝑦∀𝑧((𝑦 ∈ 𝑧 ∧ 𝑧 ∈ 𝑤) → ∃𝑤∀𝑦(∃𝑤((𝑦 ∈ 𝑧 ∧ 𝑧 ∈ 𝑤) ∧ (𝑦 ∈ 𝑤 ∧ 𝑤 ∈ 𝑣)) ↔ 𝑦 = 𝑤))) | 
| 40 |  | nfcvd 2906 | . . . . . . . . 9
⊢ ((¬
∀𝑥 𝑥 = 𝑧 ∧ ¬ ∀𝑥 𝑥 = 𝑦 ∧ ¬ ∀𝑥 𝑥 = 𝑤) → Ⅎ𝑦𝑣) | 
| 41 |  | nfcvf2 2933 | . . . . . . . . . 10
⊢ (¬
∀𝑥 𝑥 = 𝑦 → Ⅎ𝑦𝑥) | 
| 42 | 41 | 3ad2ant2 1135 | . . . . . . . . 9
⊢ ((¬
∀𝑥 𝑥 = 𝑧 ∧ ¬ ∀𝑥 𝑥 = 𝑦 ∧ ¬ ∀𝑥 𝑥 = 𝑤) → Ⅎ𝑦𝑥) | 
| 43 | 40, 42 | nfeqd 2916 | . . . . . . . 8
⊢ ((¬
∀𝑥 𝑥 = 𝑧 ∧ ¬ ∀𝑥 𝑥 = 𝑦 ∧ ¬ ∀𝑥 𝑥 = 𝑤) → Ⅎ𝑦 𝑣 = 𝑥) | 
| 44 | 9, 43 | nfan1 2200 | . . . . . . 7
⊢
Ⅎ𝑦((¬
∀𝑥 𝑥 = 𝑧 ∧ ¬ ∀𝑥 𝑥 = 𝑦 ∧ ¬ ∀𝑥 𝑥 = 𝑤) ∧ 𝑣 = 𝑥) | 
| 45 |  | nfcvd 2906 | . . . . . . . . . 10
⊢ ((¬
∀𝑥 𝑥 = 𝑧 ∧ ¬ ∀𝑥 𝑥 = 𝑦 ∧ ¬ ∀𝑥 𝑥 = 𝑤) → Ⅎ𝑧𝑣) | 
| 46 |  | nfcvf2 2933 | . . . . . . . . . . 11
⊢ (¬
∀𝑥 𝑥 = 𝑧 → Ⅎ𝑧𝑥) | 
| 47 | 46 | 3ad2ant1 1134 | . . . . . . . . . 10
⊢ ((¬
∀𝑥 𝑥 = 𝑧 ∧ ¬ ∀𝑥 𝑥 = 𝑦 ∧ ¬ ∀𝑥 𝑥 = 𝑤) → Ⅎ𝑧𝑥) | 
| 48 | 45, 47 | nfeqd 2916 | . . . . . . . . 9
⊢ ((¬
∀𝑥 𝑥 = 𝑧 ∧ ¬ ∀𝑥 𝑥 = 𝑦 ∧ ¬ ∀𝑥 𝑥 = 𝑤) → Ⅎ𝑧 𝑣 = 𝑥) | 
| 49 | 13, 48 | nfan1 2200 | . . . . . . . 8
⊢
Ⅎ𝑧((¬
∀𝑥 𝑥 = 𝑧 ∧ ¬ ∀𝑥 𝑥 = 𝑦 ∧ ¬ ∀𝑥 𝑥 = 𝑤) ∧ 𝑣 = 𝑥) | 
| 50 | 22 | nf5rd 2196 | . . . . . . . . . . 11
⊢ ((¬
∀𝑥 𝑥 = 𝑧 ∧ ¬ ∀𝑥 𝑥 = 𝑦 ∧ ¬ ∀𝑥 𝑥 = 𝑤) → ((𝑦 ∈ 𝑧 ∧ 𝑧 ∈ 𝑤) → ∀𝑥(𝑦 ∈ 𝑧 ∧ 𝑧 ∈ 𝑤))) | 
| 51 | 50 | adantr 480 | . . . . . . . . . 10
⊢ (((¬
∀𝑥 𝑥 = 𝑧 ∧ ¬ ∀𝑥 𝑥 = 𝑦 ∧ ¬ ∀𝑥 𝑥 = 𝑤) ∧ 𝑣 = 𝑥) → ((𝑦 ∈ 𝑧 ∧ 𝑧 ∈ 𝑤) → ∀𝑥(𝑦 ∈ 𝑧 ∧ 𝑧 ∈ 𝑤))) | 
| 52 |  | sp 2183 | . . . . . . . . . 10
⊢
(∀𝑥(𝑦 ∈ 𝑧 ∧ 𝑧 ∈ 𝑤) → (𝑦 ∈ 𝑧 ∧ 𝑧 ∈ 𝑤)) | 
| 53 | 51, 52 | impbid1 225 | . . . . . . . . 9
⊢ (((¬
∀𝑥 𝑥 = 𝑧 ∧ ¬ ∀𝑥 𝑥 = 𝑦 ∧ ¬ ∀𝑥 𝑥 = 𝑤) ∧ 𝑣 = 𝑥) → ((𝑦 ∈ 𝑧 ∧ 𝑧 ∈ 𝑤) ↔ ∀𝑥(𝑦 ∈ 𝑧 ∧ 𝑧 ∈ 𝑤))) | 
| 54 |  | nfcvd 2906 | . . . . . . . . . . . 12
⊢ ((¬
∀𝑥 𝑥 = 𝑧 ∧ ¬ ∀𝑥 𝑥 = 𝑦 ∧ ¬ ∀𝑥 𝑥 = 𝑤) → Ⅎ𝑤𝑣) | 
| 55 |  | nfcvf2 2933 | . . . . . . . . . . . . 13
⊢ (¬
∀𝑥 𝑥 = 𝑤 → Ⅎ𝑤𝑥) | 
| 56 | 55 | 3ad2ant3 1136 | . . . . . . . . . . . 12
⊢ ((¬
∀𝑥 𝑥 = 𝑧 ∧ ¬ ∀𝑥 𝑥 = 𝑦 ∧ ¬ ∀𝑥 𝑥 = 𝑤) → Ⅎ𝑤𝑥) | 
| 57 | 54, 56 | nfeqd 2916 | . . . . . . . . . . 11
⊢ ((¬
∀𝑥 𝑥 = 𝑧 ∧ ¬ ∀𝑥 𝑥 = 𝑦 ∧ ¬ ∀𝑥 𝑥 = 𝑤) → Ⅎ𝑤 𝑣 = 𝑥) | 
| 58 | 26, 57 | nfan1 2200 | . . . . . . . . . 10
⊢
Ⅎ𝑤((¬
∀𝑥 𝑥 = 𝑧 ∧ ¬ ∀𝑥 𝑥 = 𝑦 ∧ ¬ ∀𝑥 𝑥 = 𝑤) ∧ 𝑣 = 𝑥) | 
| 59 |  | simpr 484 | . . . . . . . . . . . . . . . 16
⊢ (((¬
∀𝑥 𝑥 = 𝑧 ∧ ¬ ∀𝑥 𝑥 = 𝑦 ∧ ¬ ∀𝑥 𝑥 = 𝑤) ∧ 𝑣 = 𝑥) → 𝑣 = 𝑥) | 
| 60 | 59 | eleq2d 2827 | . . . . . . . . . . . . . . 15
⊢ (((¬
∀𝑥 𝑥 = 𝑧 ∧ ¬ ∀𝑥 𝑥 = 𝑦 ∧ ¬ ∀𝑥 𝑥 = 𝑤) ∧ 𝑣 = 𝑥) → (𝑤 ∈ 𝑣 ↔ 𝑤 ∈ 𝑥)) | 
| 61 | 60 | anbi2d 630 | . . . . . . . . . . . . . 14
⊢ (((¬
∀𝑥 𝑥 = 𝑧 ∧ ¬ ∀𝑥 𝑥 = 𝑦 ∧ ¬ ∀𝑥 𝑥 = 𝑤) ∧ 𝑣 = 𝑥) → ((𝑦 ∈ 𝑤 ∧ 𝑤 ∈ 𝑣) ↔ (𝑦 ∈ 𝑤 ∧ 𝑤 ∈ 𝑥))) | 
| 62 | 61 | anbi2d 630 | . . . . . . . . . . . . 13
⊢ (((¬
∀𝑥 𝑥 = 𝑧 ∧ ¬ ∀𝑥 𝑥 = 𝑦 ∧ ¬ ∀𝑥 𝑥 = 𝑤) ∧ 𝑣 = 𝑥) → (((𝑦 ∈ 𝑧 ∧ 𝑧 ∈ 𝑤) ∧ (𝑦 ∈ 𝑤 ∧ 𝑤 ∈ 𝑣)) ↔ ((𝑦 ∈ 𝑧 ∧ 𝑧 ∈ 𝑤) ∧ (𝑦 ∈ 𝑤 ∧ 𝑤 ∈ 𝑥)))) | 
| 63 | 58, 62 | exbid 2223 | . . . . . . . . . . . 12
⊢ (((¬
∀𝑥 𝑥 = 𝑧 ∧ ¬ ∀𝑥 𝑥 = 𝑦 ∧ ¬ ∀𝑥 𝑥 = 𝑤) ∧ 𝑣 = 𝑥) → (∃𝑤((𝑦 ∈ 𝑧 ∧ 𝑧 ∈ 𝑤) ∧ (𝑦 ∈ 𝑤 ∧ 𝑤 ∈ 𝑣)) ↔ ∃𝑤((𝑦 ∈ 𝑧 ∧ 𝑧 ∈ 𝑤) ∧ (𝑦 ∈ 𝑤 ∧ 𝑤 ∈ 𝑥)))) | 
| 64 | 63 | bibi1d 343 | . . . . . . . . . . 11
⊢ (((¬
∀𝑥 𝑥 = 𝑧 ∧ ¬ ∀𝑥 𝑥 = 𝑦 ∧ ¬ ∀𝑥 𝑥 = 𝑤) ∧ 𝑣 = 𝑥) → ((∃𝑤((𝑦 ∈ 𝑧 ∧ 𝑧 ∈ 𝑤) ∧ (𝑦 ∈ 𝑤 ∧ 𝑤 ∈ 𝑣)) ↔ 𝑦 = 𝑤) ↔ (∃𝑤((𝑦 ∈ 𝑧 ∧ 𝑧 ∈ 𝑤) ∧ (𝑦 ∈ 𝑤 ∧ 𝑤 ∈ 𝑥)) ↔ 𝑦 = 𝑤))) | 
| 65 | 44, 64 | albid 2222 | . . . . . . . . . 10
⊢ (((¬
∀𝑥 𝑥 = 𝑧 ∧ ¬ ∀𝑥 𝑥 = 𝑦 ∧ ¬ ∀𝑥 𝑥 = 𝑤) ∧ 𝑣 = 𝑥) → (∀𝑦(∃𝑤((𝑦 ∈ 𝑧 ∧ 𝑧 ∈ 𝑤) ∧ (𝑦 ∈ 𝑤 ∧ 𝑤 ∈ 𝑣)) ↔ 𝑦 = 𝑤) ↔ ∀𝑦(∃𝑤((𝑦 ∈ 𝑧 ∧ 𝑧 ∈ 𝑤) ∧ (𝑦 ∈ 𝑤 ∧ 𝑤 ∈ 𝑥)) ↔ 𝑦 = 𝑤))) | 
| 66 | 58, 65 | exbid 2223 | . . . . . . . . 9
⊢ (((¬
∀𝑥 𝑥 = 𝑧 ∧ ¬ ∀𝑥 𝑥 = 𝑦 ∧ ¬ ∀𝑥 𝑥 = 𝑤) ∧ 𝑣 = 𝑥) → (∃𝑤∀𝑦(∃𝑤((𝑦 ∈ 𝑧 ∧ 𝑧 ∈ 𝑤) ∧ (𝑦 ∈ 𝑤 ∧ 𝑤 ∈ 𝑣)) ↔ 𝑦 = 𝑤) ↔ ∃𝑤∀𝑦(∃𝑤((𝑦 ∈ 𝑧 ∧ 𝑧 ∈ 𝑤) ∧ (𝑦 ∈ 𝑤 ∧ 𝑤 ∈ 𝑥)) ↔ 𝑦 = 𝑤))) | 
| 67 | 53, 66 | imbi12d 344 | . . . . . . . 8
⊢ (((¬
∀𝑥 𝑥 = 𝑧 ∧ ¬ ∀𝑥 𝑥 = 𝑦 ∧ ¬ ∀𝑥 𝑥 = 𝑤) ∧ 𝑣 = 𝑥) → (((𝑦 ∈ 𝑧 ∧ 𝑧 ∈ 𝑤) → ∃𝑤∀𝑦(∃𝑤((𝑦 ∈ 𝑧 ∧ 𝑧 ∈ 𝑤) ∧ (𝑦 ∈ 𝑤 ∧ 𝑤 ∈ 𝑣)) ↔ 𝑦 = 𝑤)) ↔ (∀𝑥(𝑦 ∈ 𝑧 ∧ 𝑧 ∈ 𝑤) → ∃𝑤∀𝑦(∃𝑤((𝑦 ∈ 𝑧 ∧ 𝑧 ∈ 𝑤) ∧ (𝑦 ∈ 𝑤 ∧ 𝑤 ∈ 𝑥)) ↔ 𝑦 = 𝑤)))) | 
| 68 | 49, 67 | albid 2222 | . . . . . . 7
⊢ (((¬
∀𝑥 𝑥 = 𝑧 ∧ ¬ ∀𝑥 𝑥 = 𝑦 ∧ ¬ ∀𝑥 𝑥 = 𝑤) ∧ 𝑣 = 𝑥) → (∀𝑧((𝑦 ∈ 𝑧 ∧ 𝑧 ∈ 𝑤) → ∃𝑤∀𝑦(∃𝑤((𝑦 ∈ 𝑧 ∧ 𝑧 ∈ 𝑤) ∧ (𝑦 ∈ 𝑤 ∧ 𝑤 ∈ 𝑣)) ↔ 𝑦 = 𝑤)) ↔ ∀𝑧(∀𝑥(𝑦 ∈ 𝑧 ∧ 𝑧 ∈ 𝑤) → ∃𝑤∀𝑦(∃𝑤((𝑦 ∈ 𝑧 ∧ 𝑧 ∈ 𝑤) ∧ (𝑦 ∈ 𝑤 ∧ 𝑤 ∈ 𝑥)) ↔ 𝑦 = 𝑤)))) | 
| 69 | 44, 68 | albid 2222 | . . . . . 6
⊢ (((¬
∀𝑥 𝑥 = 𝑧 ∧ ¬ ∀𝑥 𝑥 = 𝑦 ∧ ¬ ∀𝑥 𝑥 = 𝑤) ∧ 𝑣 = 𝑥) → (∀𝑦∀𝑧((𝑦 ∈ 𝑧 ∧ 𝑧 ∈ 𝑤) → ∃𝑤∀𝑦(∃𝑤((𝑦 ∈ 𝑧 ∧ 𝑧 ∈ 𝑤) ∧ (𝑦 ∈ 𝑤 ∧ 𝑤 ∈ 𝑣)) ↔ 𝑦 = 𝑤)) ↔ ∀𝑦∀𝑧(∀𝑥(𝑦 ∈ 𝑧 ∧ 𝑧 ∈ 𝑤) → ∃𝑤∀𝑦(∃𝑤((𝑦 ∈ 𝑧 ∧ 𝑧 ∈ 𝑤) ∧ (𝑦 ∈ 𝑤 ∧ 𝑤 ∈ 𝑥)) ↔ 𝑦 = 𝑤)))) | 
| 70 | 69 | ex 412 | . . . . 5
⊢ ((¬
∀𝑥 𝑥 = 𝑧 ∧ ¬ ∀𝑥 𝑥 = 𝑦 ∧ ¬ ∀𝑥 𝑥 = 𝑤) → (𝑣 = 𝑥 → (∀𝑦∀𝑧((𝑦 ∈ 𝑧 ∧ 𝑧 ∈ 𝑤) → ∃𝑤∀𝑦(∃𝑤((𝑦 ∈ 𝑧 ∧ 𝑧 ∈ 𝑤) ∧ (𝑦 ∈ 𝑤 ∧ 𝑤 ∈ 𝑣)) ↔ 𝑦 = 𝑤)) ↔ ∀𝑦∀𝑧(∀𝑥(𝑦 ∈ 𝑧 ∧ 𝑧 ∈ 𝑤) → ∃𝑤∀𝑦(∃𝑤((𝑦 ∈ 𝑧 ∧ 𝑧 ∈ 𝑤) ∧ (𝑦 ∈ 𝑤 ∧ 𝑤 ∈ 𝑥)) ↔ 𝑦 = 𝑤))))) | 
| 71 | 5, 39, 70 | cbvexd 2413 | . . . 4
⊢ ((¬
∀𝑥 𝑥 = 𝑧 ∧ ¬ ∀𝑥 𝑥 = 𝑦 ∧ ¬ ∀𝑥 𝑥 = 𝑤) → (∃𝑣∀𝑦∀𝑧((𝑦 ∈ 𝑧 ∧ 𝑧 ∈ 𝑤) → ∃𝑤∀𝑦(∃𝑤((𝑦 ∈ 𝑧 ∧ 𝑧 ∈ 𝑤) ∧ (𝑦 ∈ 𝑤 ∧ 𝑤 ∈ 𝑣)) ↔ 𝑦 = 𝑤)) ↔ ∃𝑥∀𝑦∀𝑧(∀𝑥(𝑦 ∈ 𝑧 ∧ 𝑧 ∈ 𝑤) → ∃𝑤∀𝑦(∃𝑤((𝑦 ∈ 𝑧 ∧ 𝑧 ∈ 𝑤) ∧ (𝑦 ∈ 𝑤 ∧ 𝑤 ∈ 𝑥)) ↔ 𝑦 = 𝑤)))) | 
| 72 | 1, 71 | mpbii 233 | . . 3
⊢ ((¬
∀𝑥 𝑥 = 𝑧 ∧ ¬ ∀𝑥 𝑥 = 𝑦 ∧ ¬ ∀𝑥 𝑥 = 𝑤) → ∃𝑥∀𝑦∀𝑧(∀𝑥(𝑦 ∈ 𝑧 ∧ 𝑧 ∈ 𝑤) → ∃𝑤∀𝑦(∃𝑤((𝑦 ∈ 𝑧 ∧ 𝑧 ∈ 𝑤) ∧ (𝑦 ∈ 𝑤 ∧ 𝑤 ∈ 𝑥)) ↔ 𝑦 = 𝑤))) | 
| 73 | 72 | 3exp 1120 | . 2
⊢ (¬
∀𝑥 𝑥 = 𝑧 → (¬ ∀𝑥 𝑥 = 𝑦 → (¬ ∀𝑥 𝑥 = 𝑤 → ∃𝑥∀𝑦∀𝑧(∀𝑥(𝑦 ∈ 𝑧 ∧ 𝑧 ∈ 𝑤) → ∃𝑤∀𝑦(∃𝑤((𝑦 ∈ 𝑧 ∧ 𝑧 ∈ 𝑤) ∧ (𝑦 ∈ 𝑤 ∧ 𝑤 ∈ 𝑥)) ↔ 𝑦 = 𝑤))))) | 
| 74 |  | axacndlem2 10648 | . 2
⊢
(∀𝑥 𝑥 = 𝑧 → ∃𝑥∀𝑦∀𝑧(∀𝑥(𝑦 ∈ 𝑧 ∧ 𝑧 ∈ 𝑤) → ∃𝑤∀𝑦(∃𝑤((𝑦 ∈ 𝑧 ∧ 𝑧 ∈ 𝑤) ∧ (𝑦 ∈ 𝑤 ∧ 𝑤 ∈ 𝑥)) ↔ 𝑦 = 𝑤))) | 
| 75 |  | axacndlem1 10647 | . 2
⊢
(∀𝑥 𝑥 = 𝑦 → ∃𝑥∀𝑦∀𝑧(∀𝑥(𝑦 ∈ 𝑧 ∧ 𝑧 ∈ 𝑤) → ∃𝑤∀𝑦(∃𝑤((𝑦 ∈ 𝑧 ∧ 𝑧 ∈ 𝑤) ∧ (𝑦 ∈ 𝑤 ∧ 𝑤 ∈ 𝑥)) ↔ 𝑦 = 𝑤))) | 
| 76 |  | nfae 2438 | . . . 4
⊢
Ⅎ𝑦∀𝑥 𝑥 = 𝑤 | 
| 77 |  | nfae 2438 | . . . . 5
⊢
Ⅎ𝑧∀𝑥 𝑥 = 𝑤 | 
| 78 |  | simpr 484 | . . . . . . 7
⊢ ((𝑦 ∈ 𝑧 ∧ 𝑧 ∈ 𝑤) → 𝑧 ∈ 𝑤) | 
| 79 | 78 | alimi 1811 | . . . . . 6
⊢
(∀𝑥(𝑦 ∈ 𝑧 ∧ 𝑧 ∈ 𝑤) → ∀𝑥 𝑧 ∈ 𝑤) | 
| 80 |  | nd2 10628 | . . . . . . 7
⊢
(∀𝑥 𝑥 = 𝑤 → ¬ ∀𝑥 𝑧 ∈ 𝑤) | 
| 81 | 80 | pm2.21d 121 | . . . . . 6
⊢
(∀𝑥 𝑥 = 𝑤 → (∀𝑥 𝑧 ∈ 𝑤 → ∃𝑤∀𝑦(∃𝑤((𝑦 ∈ 𝑧 ∧ 𝑧 ∈ 𝑤) ∧ (𝑦 ∈ 𝑤 ∧ 𝑤 ∈ 𝑥)) ↔ 𝑦 = 𝑤))) | 
| 82 | 79, 81 | syl5 34 | . . . . 5
⊢
(∀𝑥 𝑥 = 𝑤 → (∀𝑥(𝑦 ∈ 𝑧 ∧ 𝑧 ∈ 𝑤) → ∃𝑤∀𝑦(∃𝑤((𝑦 ∈ 𝑧 ∧ 𝑧 ∈ 𝑤) ∧ (𝑦 ∈ 𝑤 ∧ 𝑤 ∈ 𝑥)) ↔ 𝑦 = 𝑤))) | 
| 83 | 77, 82 | alrimi 2213 | . . . 4
⊢
(∀𝑥 𝑥 = 𝑤 → ∀𝑧(∀𝑥(𝑦 ∈ 𝑧 ∧ 𝑧 ∈ 𝑤) → ∃𝑤∀𝑦(∃𝑤((𝑦 ∈ 𝑧 ∧ 𝑧 ∈ 𝑤) ∧ (𝑦 ∈ 𝑤 ∧ 𝑤 ∈ 𝑥)) ↔ 𝑦 = 𝑤))) | 
| 84 | 76, 83 | alrimi 2213 | . . 3
⊢
(∀𝑥 𝑥 = 𝑤 → ∀𝑦∀𝑧(∀𝑥(𝑦 ∈ 𝑧 ∧ 𝑧 ∈ 𝑤) → ∃𝑤∀𝑦(∃𝑤((𝑦 ∈ 𝑧 ∧ 𝑧 ∈ 𝑤) ∧ (𝑦 ∈ 𝑤 ∧ 𝑤 ∈ 𝑥)) ↔ 𝑦 = 𝑤))) | 
| 85 | 84 | 19.8ad 2182 | . 2
⊢
(∀𝑥 𝑥 = 𝑤 → ∃𝑥∀𝑦∀𝑧(∀𝑥(𝑦 ∈ 𝑧 ∧ 𝑧 ∈ 𝑤) → ∃𝑤∀𝑦(∃𝑤((𝑦 ∈ 𝑧 ∧ 𝑧 ∈ 𝑤) ∧ (𝑦 ∈ 𝑤 ∧ 𝑤 ∈ 𝑥)) ↔ 𝑦 = 𝑤))) | 
| 86 | 73, 74, 75, 85 | pm2.61iii 185 | 1
⊢
∃𝑥∀𝑦∀𝑧(∀𝑥(𝑦 ∈ 𝑧 ∧ 𝑧 ∈ 𝑤) → ∃𝑤∀𝑦(∃𝑤((𝑦 ∈ 𝑧 ∧ 𝑧 ∈ 𝑤) ∧ (𝑦 ∈ 𝑤 ∧ 𝑤 ∈ 𝑥)) ↔ 𝑦 = 𝑤)) |