| Step | Hyp | Ref | Expression | 
						
							| 1 |  | axacndlem4 | ⊢ ∃ 𝑥 ∀ 𝑣 ∀ 𝑧 ( ∀ 𝑥 ( 𝑣  ∈  𝑧  ∧  𝑧  ∈  𝑤 )  →  ∃ 𝑤 ∀ 𝑣 ( ∃ 𝑤 ( ( 𝑣  ∈  𝑧  ∧  𝑧  ∈  𝑤 )  ∧  ( 𝑣  ∈  𝑤  ∧  𝑤  ∈  𝑥 ) )  ↔  𝑣  =  𝑤 ) ) | 
						
							| 2 |  | nfnae | ⊢ Ⅎ 𝑥 ¬  ∀ 𝑦 𝑦  =  𝑧 | 
						
							| 3 |  | nfnae | ⊢ Ⅎ 𝑥 ¬  ∀ 𝑦 𝑦  =  𝑥 | 
						
							| 4 |  | nfnae | ⊢ Ⅎ 𝑥 ¬  ∀ 𝑦 𝑦  =  𝑤 | 
						
							| 5 | 2 3 4 | nf3an | ⊢ Ⅎ 𝑥 ( ¬  ∀ 𝑦 𝑦  =  𝑧  ∧  ¬  ∀ 𝑦 𝑦  =  𝑥  ∧  ¬  ∀ 𝑦 𝑦  =  𝑤 ) | 
						
							| 6 |  | nfnae | ⊢ Ⅎ 𝑦 ¬  ∀ 𝑦 𝑦  =  𝑧 | 
						
							| 7 |  | nfnae | ⊢ Ⅎ 𝑦 ¬  ∀ 𝑦 𝑦  =  𝑥 | 
						
							| 8 |  | nfnae | ⊢ Ⅎ 𝑦 ¬  ∀ 𝑦 𝑦  =  𝑤 | 
						
							| 9 | 6 7 8 | nf3an | ⊢ Ⅎ 𝑦 ( ¬  ∀ 𝑦 𝑦  =  𝑧  ∧  ¬  ∀ 𝑦 𝑦  =  𝑥  ∧  ¬  ∀ 𝑦 𝑦  =  𝑤 ) | 
						
							| 10 |  | nfnae | ⊢ Ⅎ 𝑧 ¬  ∀ 𝑦 𝑦  =  𝑧 | 
						
							| 11 |  | nfnae | ⊢ Ⅎ 𝑧 ¬  ∀ 𝑦 𝑦  =  𝑥 | 
						
							| 12 |  | nfnae | ⊢ Ⅎ 𝑧 ¬  ∀ 𝑦 𝑦  =  𝑤 | 
						
							| 13 | 10 11 12 | nf3an | ⊢ Ⅎ 𝑧 ( ¬  ∀ 𝑦 𝑦  =  𝑧  ∧  ¬  ∀ 𝑦 𝑦  =  𝑥  ∧  ¬  ∀ 𝑦 𝑦  =  𝑤 ) | 
						
							| 14 |  | nfcvd | ⊢ ( ( ¬  ∀ 𝑦 𝑦  =  𝑧  ∧  ¬  ∀ 𝑦 𝑦  =  𝑥  ∧  ¬  ∀ 𝑦 𝑦  =  𝑤 )  →  Ⅎ 𝑦 𝑣 ) | 
						
							| 15 |  | nfcvf | ⊢ ( ¬  ∀ 𝑦 𝑦  =  𝑧  →  Ⅎ 𝑦 𝑧 ) | 
						
							| 16 | 15 | 3ad2ant1 | ⊢ ( ( ¬  ∀ 𝑦 𝑦  =  𝑧  ∧  ¬  ∀ 𝑦 𝑦  =  𝑥  ∧  ¬  ∀ 𝑦 𝑦  =  𝑤 )  →  Ⅎ 𝑦 𝑧 ) | 
						
							| 17 | 14 16 | nfeld | ⊢ ( ( ¬  ∀ 𝑦 𝑦  =  𝑧  ∧  ¬  ∀ 𝑦 𝑦  =  𝑥  ∧  ¬  ∀ 𝑦 𝑦  =  𝑤 )  →  Ⅎ 𝑦 𝑣  ∈  𝑧 ) | 
						
							| 18 |  | nfcvf | ⊢ ( ¬  ∀ 𝑦 𝑦  =  𝑤  →  Ⅎ 𝑦 𝑤 ) | 
						
							| 19 | 18 | 3ad2ant3 | ⊢ ( ( ¬  ∀ 𝑦 𝑦  =  𝑧  ∧  ¬  ∀ 𝑦 𝑦  =  𝑥  ∧  ¬  ∀ 𝑦 𝑦  =  𝑤 )  →  Ⅎ 𝑦 𝑤 ) | 
						
							| 20 | 16 19 | nfeld | ⊢ ( ( ¬  ∀ 𝑦 𝑦  =  𝑧  ∧  ¬  ∀ 𝑦 𝑦  =  𝑥  ∧  ¬  ∀ 𝑦 𝑦  =  𝑤 )  →  Ⅎ 𝑦 𝑧  ∈  𝑤 ) | 
						
							| 21 | 17 20 | nfand | ⊢ ( ( ¬  ∀ 𝑦 𝑦  =  𝑧  ∧  ¬  ∀ 𝑦 𝑦  =  𝑥  ∧  ¬  ∀ 𝑦 𝑦  =  𝑤 )  →  Ⅎ 𝑦 ( 𝑣  ∈  𝑧  ∧  𝑧  ∈  𝑤 ) ) | 
						
							| 22 | 5 21 | nfald | ⊢ ( ( ¬  ∀ 𝑦 𝑦  =  𝑧  ∧  ¬  ∀ 𝑦 𝑦  =  𝑥  ∧  ¬  ∀ 𝑦 𝑦  =  𝑤 )  →  Ⅎ 𝑦 ∀ 𝑥 ( 𝑣  ∈  𝑧  ∧  𝑧  ∈  𝑤 ) ) | 
						
							| 23 |  | nfnae | ⊢ Ⅎ 𝑤 ¬  ∀ 𝑦 𝑦  =  𝑧 | 
						
							| 24 |  | nfnae | ⊢ Ⅎ 𝑤 ¬  ∀ 𝑦 𝑦  =  𝑥 | 
						
							| 25 |  | nfnae | ⊢ Ⅎ 𝑤 ¬  ∀ 𝑦 𝑦  =  𝑤 | 
						
							| 26 | 23 24 25 | nf3an | ⊢ Ⅎ 𝑤 ( ¬  ∀ 𝑦 𝑦  =  𝑧  ∧  ¬  ∀ 𝑦 𝑦  =  𝑥  ∧  ¬  ∀ 𝑦 𝑦  =  𝑤 ) | 
						
							| 27 |  | nfv | ⊢ Ⅎ 𝑣 ( ¬  ∀ 𝑦 𝑦  =  𝑧  ∧  ¬  ∀ 𝑦 𝑦  =  𝑥  ∧  ¬  ∀ 𝑦 𝑦  =  𝑤 ) | 
						
							| 28 | 14 19 | nfeld | ⊢ ( ( ¬  ∀ 𝑦 𝑦  =  𝑧  ∧  ¬  ∀ 𝑦 𝑦  =  𝑥  ∧  ¬  ∀ 𝑦 𝑦  =  𝑤 )  →  Ⅎ 𝑦 𝑣  ∈  𝑤 ) | 
						
							| 29 |  | nfcvf | ⊢ ( ¬  ∀ 𝑦 𝑦  =  𝑥  →  Ⅎ 𝑦 𝑥 ) | 
						
							| 30 | 29 | 3ad2ant2 | ⊢ ( ( ¬  ∀ 𝑦 𝑦  =  𝑧  ∧  ¬  ∀ 𝑦 𝑦  =  𝑥  ∧  ¬  ∀ 𝑦 𝑦  =  𝑤 )  →  Ⅎ 𝑦 𝑥 ) | 
						
							| 31 | 19 30 | nfeld | ⊢ ( ( ¬  ∀ 𝑦 𝑦  =  𝑧  ∧  ¬  ∀ 𝑦 𝑦  =  𝑥  ∧  ¬  ∀ 𝑦 𝑦  =  𝑤 )  →  Ⅎ 𝑦 𝑤  ∈  𝑥 ) | 
						
							| 32 | 28 31 | nfand | ⊢ ( ( ¬  ∀ 𝑦 𝑦  =  𝑧  ∧  ¬  ∀ 𝑦 𝑦  =  𝑥  ∧  ¬  ∀ 𝑦 𝑦  =  𝑤 )  →  Ⅎ 𝑦 ( 𝑣  ∈  𝑤  ∧  𝑤  ∈  𝑥 ) ) | 
						
							| 33 | 21 32 | nfand | ⊢ ( ( ¬  ∀ 𝑦 𝑦  =  𝑧  ∧  ¬  ∀ 𝑦 𝑦  =  𝑥  ∧  ¬  ∀ 𝑦 𝑦  =  𝑤 )  →  Ⅎ 𝑦 ( ( 𝑣  ∈  𝑧  ∧  𝑧  ∈  𝑤 )  ∧  ( 𝑣  ∈  𝑤  ∧  𝑤  ∈  𝑥 ) ) ) | 
						
							| 34 | 26 33 | nfexd | ⊢ ( ( ¬  ∀ 𝑦 𝑦  =  𝑧  ∧  ¬  ∀ 𝑦 𝑦  =  𝑥  ∧  ¬  ∀ 𝑦 𝑦  =  𝑤 )  →  Ⅎ 𝑦 ∃ 𝑤 ( ( 𝑣  ∈  𝑧  ∧  𝑧  ∈  𝑤 )  ∧  ( 𝑣  ∈  𝑤  ∧  𝑤  ∈  𝑥 ) ) ) | 
						
							| 35 | 14 19 | nfeqd | ⊢ ( ( ¬  ∀ 𝑦 𝑦  =  𝑧  ∧  ¬  ∀ 𝑦 𝑦  =  𝑥  ∧  ¬  ∀ 𝑦 𝑦  =  𝑤 )  →  Ⅎ 𝑦 𝑣  =  𝑤 ) | 
						
							| 36 | 34 35 | nfbid | ⊢ ( ( ¬  ∀ 𝑦 𝑦  =  𝑧  ∧  ¬  ∀ 𝑦 𝑦  =  𝑥  ∧  ¬  ∀ 𝑦 𝑦  =  𝑤 )  →  Ⅎ 𝑦 ( ∃ 𝑤 ( ( 𝑣  ∈  𝑧  ∧  𝑧  ∈  𝑤 )  ∧  ( 𝑣  ∈  𝑤  ∧  𝑤  ∈  𝑥 ) )  ↔  𝑣  =  𝑤 ) ) | 
						
							| 37 | 27 36 | nfald | ⊢ ( ( ¬  ∀ 𝑦 𝑦  =  𝑧  ∧  ¬  ∀ 𝑦 𝑦  =  𝑥  ∧  ¬  ∀ 𝑦 𝑦  =  𝑤 )  →  Ⅎ 𝑦 ∀ 𝑣 ( ∃ 𝑤 ( ( 𝑣  ∈  𝑧  ∧  𝑧  ∈  𝑤 )  ∧  ( 𝑣  ∈  𝑤  ∧  𝑤  ∈  𝑥 ) )  ↔  𝑣  =  𝑤 ) ) | 
						
							| 38 | 26 37 | nfexd | ⊢ ( ( ¬  ∀ 𝑦 𝑦  =  𝑧  ∧  ¬  ∀ 𝑦 𝑦  =  𝑥  ∧  ¬  ∀ 𝑦 𝑦  =  𝑤 )  →  Ⅎ 𝑦 ∃ 𝑤 ∀ 𝑣 ( ∃ 𝑤 ( ( 𝑣  ∈  𝑧  ∧  𝑧  ∈  𝑤 )  ∧  ( 𝑣  ∈  𝑤  ∧  𝑤  ∈  𝑥 ) )  ↔  𝑣  =  𝑤 ) ) | 
						
							| 39 | 22 38 | nfimd | ⊢ ( ( ¬  ∀ 𝑦 𝑦  =  𝑧  ∧  ¬  ∀ 𝑦 𝑦  =  𝑥  ∧  ¬  ∀ 𝑦 𝑦  =  𝑤 )  →  Ⅎ 𝑦 ( ∀ 𝑥 ( 𝑣  ∈  𝑧  ∧  𝑧  ∈  𝑤 )  →  ∃ 𝑤 ∀ 𝑣 ( ∃ 𝑤 ( ( 𝑣  ∈  𝑧  ∧  𝑧  ∈  𝑤 )  ∧  ( 𝑣  ∈  𝑤  ∧  𝑤  ∈  𝑥 ) )  ↔  𝑣  =  𝑤 ) ) ) | 
						
							| 40 | 13 39 | nfald | ⊢ ( ( ¬  ∀ 𝑦 𝑦  =  𝑧  ∧  ¬  ∀ 𝑦 𝑦  =  𝑥  ∧  ¬  ∀ 𝑦 𝑦  =  𝑤 )  →  Ⅎ 𝑦 ∀ 𝑧 ( ∀ 𝑥 ( 𝑣  ∈  𝑧  ∧  𝑧  ∈  𝑤 )  →  ∃ 𝑤 ∀ 𝑣 ( ∃ 𝑤 ( ( 𝑣  ∈  𝑧  ∧  𝑧  ∈  𝑤 )  ∧  ( 𝑣  ∈  𝑤  ∧  𝑤  ∈  𝑥 ) )  ↔  𝑣  =  𝑤 ) ) ) | 
						
							| 41 |  | nfcvd | ⊢ ( ( ¬  ∀ 𝑦 𝑦  =  𝑧  ∧  ¬  ∀ 𝑦 𝑦  =  𝑥  ∧  ¬  ∀ 𝑦 𝑦  =  𝑤 )  →  Ⅎ 𝑧 𝑣 ) | 
						
							| 42 |  | nfcvf2 | ⊢ ( ¬  ∀ 𝑦 𝑦  =  𝑧  →  Ⅎ 𝑧 𝑦 ) | 
						
							| 43 | 42 | 3ad2ant1 | ⊢ ( ( ¬  ∀ 𝑦 𝑦  =  𝑧  ∧  ¬  ∀ 𝑦 𝑦  =  𝑥  ∧  ¬  ∀ 𝑦 𝑦  =  𝑤 )  →  Ⅎ 𝑧 𝑦 ) | 
						
							| 44 | 41 43 | nfeqd | ⊢ ( ( ¬  ∀ 𝑦 𝑦  =  𝑧  ∧  ¬  ∀ 𝑦 𝑦  =  𝑥  ∧  ¬  ∀ 𝑦 𝑦  =  𝑤 )  →  Ⅎ 𝑧 𝑣  =  𝑦 ) | 
						
							| 45 | 13 44 | nfan1 | ⊢ Ⅎ 𝑧 ( ( ¬  ∀ 𝑦 𝑦  =  𝑧  ∧  ¬  ∀ 𝑦 𝑦  =  𝑥  ∧  ¬  ∀ 𝑦 𝑦  =  𝑤 )  ∧  𝑣  =  𝑦 ) | 
						
							| 46 |  | nfcvd | ⊢ ( ( ¬  ∀ 𝑦 𝑦  =  𝑧  ∧  ¬  ∀ 𝑦 𝑦  =  𝑥  ∧  ¬  ∀ 𝑦 𝑦  =  𝑤 )  →  Ⅎ 𝑥 𝑣 ) | 
						
							| 47 |  | nfcvf2 | ⊢ ( ¬  ∀ 𝑦 𝑦  =  𝑥  →  Ⅎ 𝑥 𝑦 ) | 
						
							| 48 | 47 | 3ad2ant2 | ⊢ ( ( ¬  ∀ 𝑦 𝑦  =  𝑧  ∧  ¬  ∀ 𝑦 𝑦  =  𝑥  ∧  ¬  ∀ 𝑦 𝑦  =  𝑤 )  →  Ⅎ 𝑥 𝑦 ) | 
						
							| 49 | 46 48 | nfeqd | ⊢ ( ( ¬  ∀ 𝑦 𝑦  =  𝑧  ∧  ¬  ∀ 𝑦 𝑦  =  𝑥  ∧  ¬  ∀ 𝑦 𝑦  =  𝑤 )  →  Ⅎ 𝑥 𝑣  =  𝑦 ) | 
						
							| 50 | 5 49 | nfan1 | ⊢ Ⅎ 𝑥 ( ( ¬  ∀ 𝑦 𝑦  =  𝑧  ∧  ¬  ∀ 𝑦 𝑦  =  𝑥  ∧  ¬  ∀ 𝑦 𝑦  =  𝑤 )  ∧  𝑣  =  𝑦 ) | 
						
							| 51 |  | simpr | ⊢ ( ( ( ¬  ∀ 𝑦 𝑦  =  𝑧  ∧  ¬  ∀ 𝑦 𝑦  =  𝑥  ∧  ¬  ∀ 𝑦 𝑦  =  𝑤 )  ∧  𝑣  =  𝑦 )  →  𝑣  =  𝑦 ) | 
						
							| 52 | 51 | eleq1d | ⊢ ( ( ( ¬  ∀ 𝑦 𝑦  =  𝑧  ∧  ¬  ∀ 𝑦 𝑦  =  𝑥  ∧  ¬  ∀ 𝑦 𝑦  =  𝑤 )  ∧  𝑣  =  𝑦 )  →  ( 𝑣  ∈  𝑧  ↔  𝑦  ∈  𝑧 ) ) | 
						
							| 53 | 52 | anbi1d | ⊢ ( ( ( ¬  ∀ 𝑦 𝑦  =  𝑧  ∧  ¬  ∀ 𝑦 𝑦  =  𝑥  ∧  ¬  ∀ 𝑦 𝑦  =  𝑤 )  ∧  𝑣  =  𝑦 )  →  ( ( 𝑣  ∈  𝑧  ∧  𝑧  ∈  𝑤 )  ↔  ( 𝑦  ∈  𝑧  ∧  𝑧  ∈  𝑤 ) ) ) | 
						
							| 54 | 50 53 | albid | ⊢ ( ( ( ¬  ∀ 𝑦 𝑦  =  𝑧  ∧  ¬  ∀ 𝑦 𝑦  =  𝑥  ∧  ¬  ∀ 𝑦 𝑦  =  𝑤 )  ∧  𝑣  =  𝑦 )  →  ( ∀ 𝑥 ( 𝑣  ∈  𝑧  ∧  𝑧  ∈  𝑤 )  ↔  ∀ 𝑥 ( 𝑦  ∈  𝑧  ∧  𝑧  ∈  𝑤 ) ) ) | 
						
							| 55 |  | nfcvd | ⊢ ( ( ¬  ∀ 𝑦 𝑦  =  𝑧  ∧  ¬  ∀ 𝑦 𝑦  =  𝑥  ∧  ¬  ∀ 𝑦 𝑦  =  𝑤 )  →  Ⅎ 𝑤 𝑣 ) | 
						
							| 56 |  | nfcvf2 | ⊢ ( ¬  ∀ 𝑦 𝑦  =  𝑤  →  Ⅎ 𝑤 𝑦 ) | 
						
							| 57 | 56 | 3ad2ant3 | ⊢ ( ( ¬  ∀ 𝑦 𝑦  =  𝑧  ∧  ¬  ∀ 𝑦 𝑦  =  𝑥  ∧  ¬  ∀ 𝑦 𝑦  =  𝑤 )  →  Ⅎ 𝑤 𝑦 ) | 
						
							| 58 | 55 57 | nfeqd | ⊢ ( ( ¬  ∀ 𝑦 𝑦  =  𝑧  ∧  ¬  ∀ 𝑦 𝑦  =  𝑥  ∧  ¬  ∀ 𝑦 𝑦  =  𝑤 )  →  Ⅎ 𝑤 𝑣  =  𝑦 ) | 
						
							| 59 | 26 58 | nfan1 | ⊢ Ⅎ 𝑤 ( ( ¬  ∀ 𝑦 𝑦  =  𝑧  ∧  ¬  ∀ 𝑦 𝑦  =  𝑥  ∧  ¬  ∀ 𝑦 𝑦  =  𝑤 )  ∧  𝑣  =  𝑦 ) | 
						
							| 60 | 51 | eleq1d | ⊢ ( ( ( ¬  ∀ 𝑦 𝑦  =  𝑧  ∧  ¬  ∀ 𝑦 𝑦  =  𝑥  ∧  ¬  ∀ 𝑦 𝑦  =  𝑤 )  ∧  𝑣  =  𝑦 )  →  ( 𝑣  ∈  𝑤  ↔  𝑦  ∈  𝑤 ) ) | 
						
							| 61 | 60 | anbi1d | ⊢ ( ( ( ¬  ∀ 𝑦 𝑦  =  𝑧  ∧  ¬  ∀ 𝑦 𝑦  =  𝑥  ∧  ¬  ∀ 𝑦 𝑦  =  𝑤 )  ∧  𝑣  =  𝑦 )  →  ( ( 𝑣  ∈  𝑤  ∧  𝑤  ∈  𝑥 )  ↔  ( 𝑦  ∈  𝑤  ∧  𝑤  ∈  𝑥 ) ) ) | 
						
							| 62 | 53 61 | anbi12d | ⊢ ( ( ( ¬  ∀ 𝑦 𝑦  =  𝑧  ∧  ¬  ∀ 𝑦 𝑦  =  𝑥  ∧  ¬  ∀ 𝑦 𝑦  =  𝑤 )  ∧  𝑣  =  𝑦 )  →  ( ( ( 𝑣  ∈  𝑧  ∧  𝑧  ∈  𝑤 )  ∧  ( 𝑣  ∈  𝑤  ∧  𝑤  ∈  𝑥 ) )  ↔  ( ( 𝑦  ∈  𝑧  ∧  𝑧  ∈  𝑤 )  ∧  ( 𝑦  ∈  𝑤  ∧  𝑤  ∈  𝑥 ) ) ) ) | 
						
							| 63 | 59 62 | exbid | ⊢ ( ( ( ¬  ∀ 𝑦 𝑦  =  𝑧  ∧  ¬  ∀ 𝑦 𝑦  =  𝑥  ∧  ¬  ∀ 𝑦 𝑦  =  𝑤 )  ∧  𝑣  =  𝑦 )  →  ( ∃ 𝑤 ( ( 𝑣  ∈  𝑧  ∧  𝑧  ∈  𝑤 )  ∧  ( 𝑣  ∈  𝑤  ∧  𝑤  ∈  𝑥 ) )  ↔  ∃ 𝑤 ( ( 𝑦  ∈  𝑧  ∧  𝑧  ∈  𝑤 )  ∧  ( 𝑦  ∈  𝑤  ∧  𝑤  ∈  𝑥 ) ) ) ) | 
						
							| 64 | 51 | eqeq1d | ⊢ ( ( ( ¬  ∀ 𝑦 𝑦  =  𝑧  ∧  ¬  ∀ 𝑦 𝑦  =  𝑥  ∧  ¬  ∀ 𝑦 𝑦  =  𝑤 )  ∧  𝑣  =  𝑦 )  →  ( 𝑣  =  𝑤  ↔  𝑦  =  𝑤 ) ) | 
						
							| 65 | 63 64 | bibi12d | ⊢ ( ( ( ¬  ∀ 𝑦 𝑦  =  𝑧  ∧  ¬  ∀ 𝑦 𝑦  =  𝑥  ∧  ¬  ∀ 𝑦 𝑦  =  𝑤 )  ∧  𝑣  =  𝑦 )  →  ( ( ∃ 𝑤 ( ( 𝑣  ∈  𝑧  ∧  𝑧  ∈  𝑤 )  ∧  ( 𝑣  ∈  𝑤  ∧  𝑤  ∈  𝑥 ) )  ↔  𝑣  =  𝑤 )  ↔  ( ∃ 𝑤 ( ( 𝑦  ∈  𝑧  ∧  𝑧  ∈  𝑤 )  ∧  ( 𝑦  ∈  𝑤  ∧  𝑤  ∈  𝑥 ) )  ↔  𝑦  =  𝑤 ) ) ) | 
						
							| 66 | 65 | ex | ⊢ ( ( ¬  ∀ 𝑦 𝑦  =  𝑧  ∧  ¬  ∀ 𝑦 𝑦  =  𝑥  ∧  ¬  ∀ 𝑦 𝑦  =  𝑤 )  →  ( 𝑣  =  𝑦  →  ( ( ∃ 𝑤 ( ( 𝑣  ∈  𝑧  ∧  𝑧  ∈  𝑤 )  ∧  ( 𝑣  ∈  𝑤  ∧  𝑤  ∈  𝑥 ) )  ↔  𝑣  =  𝑤 )  ↔  ( ∃ 𝑤 ( ( 𝑦  ∈  𝑧  ∧  𝑧  ∈  𝑤 )  ∧  ( 𝑦  ∈  𝑤  ∧  𝑤  ∈  𝑥 ) )  ↔  𝑦  =  𝑤 ) ) ) ) | 
						
							| 67 | 9 36 66 | cbvald | ⊢ ( ( ¬  ∀ 𝑦 𝑦  =  𝑧  ∧  ¬  ∀ 𝑦 𝑦  =  𝑥  ∧  ¬  ∀ 𝑦 𝑦  =  𝑤 )  →  ( ∀ 𝑣 ( ∃ 𝑤 ( ( 𝑣  ∈  𝑧  ∧  𝑧  ∈  𝑤 )  ∧  ( 𝑣  ∈  𝑤  ∧  𝑤  ∈  𝑥 ) )  ↔  𝑣  =  𝑤 )  ↔  ∀ 𝑦 ( ∃ 𝑤 ( ( 𝑦  ∈  𝑧  ∧  𝑧  ∈  𝑤 )  ∧  ( 𝑦  ∈  𝑤  ∧  𝑤  ∈  𝑥 ) )  ↔  𝑦  =  𝑤 ) ) ) | 
						
							| 68 | 26 67 | exbid | ⊢ ( ( ¬  ∀ 𝑦 𝑦  =  𝑧  ∧  ¬  ∀ 𝑦 𝑦  =  𝑥  ∧  ¬  ∀ 𝑦 𝑦  =  𝑤 )  →  ( ∃ 𝑤 ∀ 𝑣 ( ∃ 𝑤 ( ( 𝑣  ∈  𝑧  ∧  𝑧  ∈  𝑤 )  ∧  ( 𝑣  ∈  𝑤  ∧  𝑤  ∈  𝑥 ) )  ↔  𝑣  =  𝑤 )  ↔  ∃ 𝑤 ∀ 𝑦 ( ∃ 𝑤 ( ( 𝑦  ∈  𝑧  ∧  𝑧  ∈  𝑤 )  ∧  ( 𝑦  ∈  𝑤  ∧  𝑤  ∈  𝑥 ) )  ↔  𝑦  =  𝑤 ) ) ) | 
						
							| 69 | 68 | adantr | ⊢ ( ( ( ¬  ∀ 𝑦 𝑦  =  𝑧  ∧  ¬  ∀ 𝑦 𝑦  =  𝑥  ∧  ¬  ∀ 𝑦 𝑦  =  𝑤 )  ∧  𝑣  =  𝑦 )  →  ( ∃ 𝑤 ∀ 𝑣 ( ∃ 𝑤 ( ( 𝑣  ∈  𝑧  ∧  𝑧  ∈  𝑤 )  ∧  ( 𝑣  ∈  𝑤  ∧  𝑤  ∈  𝑥 ) )  ↔  𝑣  =  𝑤 )  ↔  ∃ 𝑤 ∀ 𝑦 ( ∃ 𝑤 ( ( 𝑦  ∈  𝑧  ∧  𝑧  ∈  𝑤 )  ∧  ( 𝑦  ∈  𝑤  ∧  𝑤  ∈  𝑥 ) )  ↔  𝑦  =  𝑤 ) ) ) | 
						
							| 70 | 54 69 | imbi12d | ⊢ ( ( ( ¬  ∀ 𝑦 𝑦  =  𝑧  ∧  ¬  ∀ 𝑦 𝑦  =  𝑥  ∧  ¬  ∀ 𝑦 𝑦  =  𝑤 )  ∧  𝑣  =  𝑦 )  →  ( ( ∀ 𝑥 ( 𝑣  ∈  𝑧  ∧  𝑧  ∈  𝑤 )  →  ∃ 𝑤 ∀ 𝑣 ( ∃ 𝑤 ( ( 𝑣  ∈  𝑧  ∧  𝑧  ∈  𝑤 )  ∧  ( 𝑣  ∈  𝑤  ∧  𝑤  ∈  𝑥 ) )  ↔  𝑣  =  𝑤 ) )  ↔  ( ∀ 𝑥 ( 𝑦  ∈  𝑧  ∧  𝑧  ∈  𝑤 )  →  ∃ 𝑤 ∀ 𝑦 ( ∃ 𝑤 ( ( 𝑦  ∈  𝑧  ∧  𝑧  ∈  𝑤 )  ∧  ( 𝑦  ∈  𝑤  ∧  𝑤  ∈  𝑥 ) )  ↔  𝑦  =  𝑤 ) ) ) ) | 
						
							| 71 | 45 70 | albid | ⊢ ( ( ( ¬  ∀ 𝑦 𝑦  =  𝑧  ∧  ¬  ∀ 𝑦 𝑦  =  𝑥  ∧  ¬  ∀ 𝑦 𝑦  =  𝑤 )  ∧  𝑣  =  𝑦 )  →  ( ∀ 𝑧 ( ∀ 𝑥 ( 𝑣  ∈  𝑧  ∧  𝑧  ∈  𝑤 )  →  ∃ 𝑤 ∀ 𝑣 ( ∃ 𝑤 ( ( 𝑣  ∈  𝑧  ∧  𝑧  ∈  𝑤 )  ∧  ( 𝑣  ∈  𝑤  ∧  𝑤  ∈  𝑥 ) )  ↔  𝑣  =  𝑤 ) )  ↔  ∀ 𝑧 ( ∀ 𝑥 ( 𝑦  ∈  𝑧  ∧  𝑧  ∈  𝑤 )  →  ∃ 𝑤 ∀ 𝑦 ( ∃ 𝑤 ( ( 𝑦  ∈  𝑧  ∧  𝑧  ∈  𝑤 )  ∧  ( 𝑦  ∈  𝑤  ∧  𝑤  ∈  𝑥 ) )  ↔  𝑦  =  𝑤 ) ) ) ) | 
						
							| 72 | 71 | ex | ⊢ ( ( ¬  ∀ 𝑦 𝑦  =  𝑧  ∧  ¬  ∀ 𝑦 𝑦  =  𝑥  ∧  ¬  ∀ 𝑦 𝑦  =  𝑤 )  →  ( 𝑣  =  𝑦  →  ( ∀ 𝑧 ( ∀ 𝑥 ( 𝑣  ∈  𝑧  ∧  𝑧  ∈  𝑤 )  →  ∃ 𝑤 ∀ 𝑣 ( ∃ 𝑤 ( ( 𝑣  ∈  𝑧  ∧  𝑧  ∈  𝑤 )  ∧  ( 𝑣  ∈  𝑤  ∧  𝑤  ∈  𝑥 ) )  ↔  𝑣  =  𝑤 ) )  ↔  ∀ 𝑧 ( ∀ 𝑥 ( 𝑦  ∈  𝑧  ∧  𝑧  ∈  𝑤 )  →  ∃ 𝑤 ∀ 𝑦 ( ∃ 𝑤 ( ( 𝑦  ∈  𝑧  ∧  𝑧  ∈  𝑤 )  ∧  ( 𝑦  ∈  𝑤  ∧  𝑤  ∈  𝑥 ) )  ↔  𝑦  =  𝑤 ) ) ) ) ) | 
						
							| 73 | 9 40 72 | cbvald | ⊢ ( ( ¬  ∀ 𝑦 𝑦  =  𝑧  ∧  ¬  ∀ 𝑦 𝑦  =  𝑥  ∧  ¬  ∀ 𝑦 𝑦  =  𝑤 )  →  ( ∀ 𝑣 ∀ 𝑧 ( ∀ 𝑥 ( 𝑣  ∈  𝑧  ∧  𝑧  ∈  𝑤 )  →  ∃ 𝑤 ∀ 𝑣 ( ∃ 𝑤 ( ( 𝑣  ∈  𝑧  ∧  𝑧  ∈  𝑤 )  ∧  ( 𝑣  ∈  𝑤  ∧  𝑤  ∈  𝑥 ) )  ↔  𝑣  =  𝑤 ) )  ↔  ∀ 𝑦 ∀ 𝑧 ( ∀ 𝑥 ( 𝑦  ∈  𝑧  ∧  𝑧  ∈  𝑤 )  →  ∃ 𝑤 ∀ 𝑦 ( ∃ 𝑤 ( ( 𝑦  ∈  𝑧  ∧  𝑧  ∈  𝑤 )  ∧  ( 𝑦  ∈  𝑤  ∧  𝑤  ∈  𝑥 ) )  ↔  𝑦  =  𝑤 ) ) ) ) | 
						
							| 74 | 5 73 | exbid | ⊢ ( ( ¬  ∀ 𝑦 𝑦  =  𝑧  ∧  ¬  ∀ 𝑦 𝑦  =  𝑥  ∧  ¬  ∀ 𝑦 𝑦  =  𝑤 )  →  ( ∃ 𝑥 ∀ 𝑣 ∀ 𝑧 ( ∀ 𝑥 ( 𝑣  ∈  𝑧  ∧  𝑧  ∈  𝑤 )  →  ∃ 𝑤 ∀ 𝑣 ( ∃ 𝑤 ( ( 𝑣  ∈  𝑧  ∧  𝑧  ∈  𝑤 )  ∧  ( 𝑣  ∈  𝑤  ∧  𝑤  ∈  𝑥 ) )  ↔  𝑣  =  𝑤 ) )  ↔  ∃ 𝑥 ∀ 𝑦 ∀ 𝑧 ( ∀ 𝑥 ( 𝑦  ∈  𝑧  ∧  𝑧  ∈  𝑤 )  →  ∃ 𝑤 ∀ 𝑦 ( ∃ 𝑤 ( ( 𝑦  ∈  𝑧  ∧  𝑧  ∈  𝑤 )  ∧  ( 𝑦  ∈  𝑤  ∧  𝑤  ∈  𝑥 ) )  ↔  𝑦  =  𝑤 ) ) ) ) | 
						
							| 75 | 1 74 | mpbii | ⊢ ( ( ¬  ∀ 𝑦 𝑦  =  𝑧  ∧  ¬  ∀ 𝑦 𝑦  =  𝑥  ∧  ¬  ∀ 𝑦 𝑦  =  𝑤 )  →  ∃ 𝑥 ∀ 𝑦 ∀ 𝑧 ( ∀ 𝑥 ( 𝑦  ∈  𝑧  ∧  𝑧  ∈  𝑤 )  →  ∃ 𝑤 ∀ 𝑦 ( ∃ 𝑤 ( ( 𝑦  ∈  𝑧  ∧  𝑧  ∈  𝑤 )  ∧  ( 𝑦  ∈  𝑤  ∧  𝑤  ∈  𝑥 ) )  ↔  𝑦  =  𝑤 ) ) ) | 
						
							| 76 | 75 | 3exp | ⊢ ( ¬  ∀ 𝑦 𝑦  =  𝑧  →  ( ¬  ∀ 𝑦 𝑦  =  𝑥  →  ( ¬  ∀ 𝑦 𝑦  =  𝑤  →  ∃ 𝑥 ∀ 𝑦 ∀ 𝑧 ( ∀ 𝑥 ( 𝑦  ∈  𝑧  ∧  𝑧  ∈  𝑤 )  →  ∃ 𝑤 ∀ 𝑦 ( ∃ 𝑤 ( ( 𝑦  ∈  𝑧  ∧  𝑧  ∈  𝑤 )  ∧  ( 𝑦  ∈  𝑤  ∧  𝑤  ∈  𝑥 ) )  ↔  𝑦  =  𝑤 ) ) ) ) ) | 
						
							| 77 |  | axacndlem3 | ⊢ ( ∀ 𝑦 𝑦  =  𝑧  →  ∃ 𝑥 ∀ 𝑦 ∀ 𝑧 ( ∀ 𝑥 ( 𝑦  ∈  𝑧  ∧  𝑧  ∈  𝑤 )  →  ∃ 𝑤 ∀ 𝑦 ( ∃ 𝑤 ( ( 𝑦  ∈  𝑧  ∧  𝑧  ∈  𝑤 )  ∧  ( 𝑦  ∈  𝑤  ∧  𝑤  ∈  𝑥 ) )  ↔  𝑦  =  𝑤 ) ) ) | 
						
							| 78 |  | axacndlem1 | ⊢ ( ∀ 𝑥 𝑥  =  𝑦  →  ∃ 𝑥 ∀ 𝑦 ∀ 𝑧 ( ∀ 𝑥 ( 𝑦  ∈  𝑧  ∧  𝑧  ∈  𝑤 )  →  ∃ 𝑤 ∀ 𝑦 ( ∃ 𝑤 ( ( 𝑦  ∈  𝑧  ∧  𝑧  ∈  𝑤 )  ∧  ( 𝑦  ∈  𝑤  ∧  𝑤  ∈  𝑥 ) )  ↔  𝑦  =  𝑤 ) ) ) | 
						
							| 79 | 78 | aecoms | ⊢ ( ∀ 𝑦 𝑦  =  𝑥  →  ∃ 𝑥 ∀ 𝑦 ∀ 𝑧 ( ∀ 𝑥 ( 𝑦  ∈  𝑧  ∧  𝑧  ∈  𝑤 )  →  ∃ 𝑤 ∀ 𝑦 ( ∃ 𝑤 ( ( 𝑦  ∈  𝑧  ∧  𝑧  ∈  𝑤 )  ∧  ( 𝑦  ∈  𝑤  ∧  𝑤  ∈  𝑥 ) )  ↔  𝑦  =  𝑤 ) ) ) | 
						
							| 80 |  | nfae | ⊢ Ⅎ 𝑧 ∀ 𝑦 𝑦  =  𝑤 | 
						
							| 81 |  | en2lp | ⊢ ¬  ( 𝑦  ∈  𝑧  ∧  𝑧  ∈  𝑦 ) | 
						
							| 82 |  | elequ2 | ⊢ ( 𝑦  =  𝑤  →  ( 𝑧  ∈  𝑦  ↔  𝑧  ∈  𝑤 ) ) | 
						
							| 83 | 82 | anbi2d | ⊢ ( 𝑦  =  𝑤  →  ( ( 𝑦  ∈  𝑧  ∧  𝑧  ∈  𝑦 )  ↔  ( 𝑦  ∈  𝑧  ∧  𝑧  ∈  𝑤 ) ) ) | 
						
							| 84 | 81 83 | mtbii | ⊢ ( 𝑦  =  𝑤  →  ¬  ( 𝑦  ∈  𝑧  ∧  𝑧  ∈  𝑤 ) ) | 
						
							| 85 | 84 | sps | ⊢ ( ∀ 𝑦 𝑦  =  𝑤  →  ¬  ( 𝑦  ∈  𝑧  ∧  𝑧  ∈  𝑤 ) ) | 
						
							| 86 | 85 | pm2.21d | ⊢ ( ∀ 𝑦 𝑦  =  𝑤  →  ( ( 𝑦  ∈  𝑧  ∧  𝑧  ∈  𝑤 )  →  ∃ 𝑤 ∀ 𝑦 ( ∃ 𝑤 ( ( 𝑦  ∈  𝑧  ∧  𝑧  ∈  𝑤 )  ∧  ( 𝑦  ∈  𝑤  ∧  𝑤  ∈  𝑥 ) )  ↔  𝑦  =  𝑤 ) ) ) | 
						
							| 87 | 86 | spsd | ⊢ ( ∀ 𝑦 𝑦  =  𝑤  →  ( ∀ 𝑥 ( 𝑦  ∈  𝑧  ∧  𝑧  ∈  𝑤 )  →  ∃ 𝑤 ∀ 𝑦 ( ∃ 𝑤 ( ( 𝑦  ∈  𝑧  ∧  𝑧  ∈  𝑤 )  ∧  ( 𝑦  ∈  𝑤  ∧  𝑤  ∈  𝑥 ) )  ↔  𝑦  =  𝑤 ) ) ) | 
						
							| 88 | 80 87 | alrimi | ⊢ ( ∀ 𝑦 𝑦  =  𝑤  →  ∀ 𝑧 ( ∀ 𝑥 ( 𝑦  ∈  𝑧  ∧  𝑧  ∈  𝑤 )  →  ∃ 𝑤 ∀ 𝑦 ( ∃ 𝑤 ( ( 𝑦  ∈  𝑧  ∧  𝑧  ∈  𝑤 )  ∧  ( 𝑦  ∈  𝑤  ∧  𝑤  ∈  𝑥 ) )  ↔  𝑦  =  𝑤 ) ) ) | 
						
							| 89 | 88 | axc4i | ⊢ ( ∀ 𝑦 𝑦  =  𝑤  →  ∀ 𝑦 ∀ 𝑧 ( ∀ 𝑥 ( 𝑦  ∈  𝑧  ∧  𝑧  ∈  𝑤 )  →  ∃ 𝑤 ∀ 𝑦 ( ∃ 𝑤 ( ( 𝑦  ∈  𝑧  ∧  𝑧  ∈  𝑤 )  ∧  ( 𝑦  ∈  𝑤  ∧  𝑤  ∈  𝑥 ) )  ↔  𝑦  =  𝑤 ) ) ) | 
						
							| 90 | 89 | 19.8ad | ⊢ ( ∀ 𝑦 𝑦  =  𝑤  →  ∃ 𝑥 ∀ 𝑦 ∀ 𝑧 ( ∀ 𝑥 ( 𝑦  ∈  𝑧  ∧  𝑧  ∈  𝑤 )  →  ∃ 𝑤 ∀ 𝑦 ( ∃ 𝑤 ( ( 𝑦  ∈  𝑧  ∧  𝑧  ∈  𝑤 )  ∧  ( 𝑦  ∈  𝑤  ∧  𝑤  ∈  𝑥 ) )  ↔  𝑦  =  𝑤 ) ) ) | 
						
							| 91 | 76 77 79 90 | pm2.61iii | ⊢ ∃ 𝑥 ∀ 𝑦 ∀ 𝑧 ( ∀ 𝑥 ( 𝑦  ∈  𝑧  ∧  𝑧  ∈  𝑤 )  →  ∃ 𝑤 ∀ 𝑦 ( ∃ 𝑤 ( ( 𝑦  ∈  𝑧  ∧  𝑧  ∈  𝑤 )  ∧  ( 𝑦  ∈  𝑤  ∧  𝑤  ∈  𝑥 ) )  ↔  𝑦  =  𝑤 ) ) |