| Step | Hyp | Ref | Expression | 
						
							| 1 |  | ellines | ⊢ ( 𝐴  ∈  LinesEE  ↔  ∃ 𝑛  ∈  ℕ ∃ 𝑎  ∈  ( 𝔼 ‘ 𝑛 ) ∃ 𝑏  ∈  ( 𝔼 ‘ 𝑛 ) ( 𝑎  ≠  𝑏  ∧  𝐴  =  ( 𝑎 Line 𝑏 ) ) ) | 
						
							| 2 |  | simpll1 | ⊢ ( ( ( ( 𝑛  ∈  ℕ  ∧  𝑎  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑏  ∈  ( 𝔼 ‘ 𝑛 ) )  ∧  𝑎  ≠  𝑏 )  ∧  ( ( 𝑃  ∈  ( 𝑎 Line 𝑏 )  ∧  𝑄  ∈  ( 𝑎 Line 𝑏 ) )  ∧  𝑃  ≠  𝑄 ) )  →  𝑛  ∈  ℕ ) | 
						
							| 3 |  | simpll2 | ⊢ ( ( ( ( 𝑛  ∈  ℕ  ∧  𝑎  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑏  ∈  ( 𝔼 ‘ 𝑛 ) )  ∧  𝑎  ≠  𝑏 )  ∧  ( ( 𝑃  ∈  ( 𝑎 Line 𝑏 )  ∧  𝑄  ∈  ( 𝑎 Line 𝑏 ) )  ∧  𝑃  ≠  𝑄 ) )  →  𝑎  ∈  ( 𝔼 ‘ 𝑛 ) ) | 
						
							| 4 |  | simpll3 | ⊢ ( ( ( ( 𝑛  ∈  ℕ  ∧  𝑎  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑏  ∈  ( 𝔼 ‘ 𝑛 ) )  ∧  𝑎  ≠  𝑏 )  ∧  ( ( 𝑃  ∈  ( 𝑎 Line 𝑏 )  ∧  𝑄  ∈  ( 𝑎 Line 𝑏 ) )  ∧  𝑃  ≠  𝑄 ) )  →  𝑏  ∈  ( 𝔼 ‘ 𝑛 ) ) | 
						
							| 5 |  | simplr | ⊢ ( ( ( ( 𝑛  ∈  ℕ  ∧  𝑎  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑏  ∈  ( 𝔼 ‘ 𝑛 ) )  ∧  𝑎  ≠  𝑏 )  ∧  ( ( 𝑃  ∈  ( 𝑎 Line 𝑏 )  ∧  𝑄  ∈  ( 𝑎 Line 𝑏 ) )  ∧  𝑃  ≠  𝑄 ) )  →  𝑎  ≠  𝑏 ) | 
						
							| 6 |  | liness | ⊢ ( ( 𝑛  ∈  ℕ  ∧  ( 𝑎  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑏  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑎  ≠  𝑏 ) )  →  ( 𝑎 Line 𝑏 )  ⊆  ( 𝔼 ‘ 𝑛 ) ) | 
						
							| 7 | 2 3 4 5 6 | syl13anc | ⊢ ( ( ( ( 𝑛  ∈  ℕ  ∧  𝑎  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑏  ∈  ( 𝔼 ‘ 𝑛 ) )  ∧  𝑎  ≠  𝑏 )  ∧  ( ( 𝑃  ∈  ( 𝑎 Line 𝑏 )  ∧  𝑄  ∈  ( 𝑎 Line 𝑏 ) )  ∧  𝑃  ≠  𝑄 ) )  →  ( 𝑎 Line 𝑏 )  ⊆  ( 𝔼 ‘ 𝑛 ) ) | 
						
							| 8 |  | simprll | ⊢ ( ( ( ( 𝑛  ∈  ℕ  ∧  𝑎  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑏  ∈  ( 𝔼 ‘ 𝑛 ) )  ∧  𝑎  ≠  𝑏 )  ∧  ( ( 𝑃  ∈  ( 𝑎 Line 𝑏 )  ∧  𝑄  ∈  ( 𝑎 Line 𝑏 ) )  ∧  𝑃  ≠  𝑄 ) )  →  𝑃  ∈  ( 𝑎 Line 𝑏 ) ) | 
						
							| 9 | 7 8 | sseldd | ⊢ ( ( ( ( 𝑛  ∈  ℕ  ∧  𝑎  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑏  ∈  ( 𝔼 ‘ 𝑛 ) )  ∧  𝑎  ≠  𝑏 )  ∧  ( ( 𝑃  ∈  ( 𝑎 Line 𝑏 )  ∧  𝑄  ∈  ( 𝑎 Line 𝑏 ) )  ∧  𝑃  ≠  𝑄 ) )  →  𝑃  ∈  ( 𝔼 ‘ 𝑛 ) ) | 
						
							| 10 |  | simprlr | ⊢ ( ( ( ( 𝑛  ∈  ℕ  ∧  𝑎  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑏  ∈  ( 𝔼 ‘ 𝑛 ) )  ∧  𝑎  ≠  𝑏 )  ∧  ( ( 𝑃  ∈  ( 𝑎 Line 𝑏 )  ∧  𝑄  ∈  ( 𝑎 Line 𝑏 ) )  ∧  𝑃  ≠  𝑄 ) )  →  𝑄  ∈  ( 𝑎 Line 𝑏 ) ) | 
						
							| 11 | 7 10 | sseldd | ⊢ ( ( ( ( 𝑛  ∈  ℕ  ∧  𝑎  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑏  ∈  ( 𝔼 ‘ 𝑛 ) )  ∧  𝑎  ≠  𝑏 )  ∧  ( ( 𝑃  ∈  ( 𝑎 Line 𝑏 )  ∧  𝑄  ∈  ( 𝑎 Line 𝑏 ) )  ∧  𝑃  ≠  𝑄 ) )  →  𝑄  ∈  ( 𝔼 ‘ 𝑛 ) ) | 
						
							| 12 |  | simplll | ⊢ ( ( ( ( 𝑃  ∈  ( 𝑎 Line 𝑏 )  ∧  𝑄  ∈  ( 𝑎 Line 𝑏 ) )  ∧  𝑃  ≠  𝑎 )  ∧  ( 𝑃  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑄  ∈  ( 𝔼 ‘ 𝑛 ) ) )  →  𝑃  ∈  ( 𝑎 Line 𝑏 ) ) | 
						
							| 13 | 12 | adantl | ⊢ ( ( ( ( 𝑛  ∈  ℕ  ∧  𝑎  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑏  ∈  ( 𝔼 ‘ 𝑛 ) )  ∧  𝑎  ≠  𝑏 )  ∧  ( ( ( 𝑃  ∈  ( 𝑎 Line 𝑏 )  ∧  𝑄  ∈  ( 𝑎 Line 𝑏 ) )  ∧  𝑃  ≠  𝑎 )  ∧  ( 𝑃  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑄  ∈  ( 𝔼 ‘ 𝑛 ) ) ) )  →  𝑃  ∈  ( 𝑎 Line 𝑏 ) ) | 
						
							| 14 |  | simpll1 | ⊢ ( ( ( ( 𝑛  ∈  ℕ  ∧  𝑎  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑏  ∈  ( 𝔼 ‘ 𝑛 ) )  ∧  𝑎  ≠  𝑏 )  ∧  ( ( ( 𝑃  ∈  ( 𝑎 Line 𝑏 )  ∧  𝑄  ∈  ( 𝑎 Line 𝑏 ) )  ∧  𝑃  ≠  𝑎 )  ∧  ( 𝑃  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑄  ∈  ( 𝔼 ‘ 𝑛 ) ) ) )  →  𝑛  ∈  ℕ ) | 
						
							| 15 |  | simpll2 | ⊢ ( ( ( ( 𝑛  ∈  ℕ  ∧  𝑎  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑏  ∈  ( 𝔼 ‘ 𝑛 ) )  ∧  𝑎  ≠  𝑏 )  ∧  ( ( ( 𝑃  ∈  ( 𝑎 Line 𝑏 )  ∧  𝑄  ∈  ( 𝑎 Line 𝑏 ) )  ∧  𝑃  ≠  𝑎 )  ∧  ( 𝑃  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑄  ∈  ( 𝔼 ‘ 𝑛 ) ) ) )  →  𝑎  ∈  ( 𝔼 ‘ 𝑛 ) ) | 
						
							| 16 |  | simpll3 | ⊢ ( ( ( ( 𝑛  ∈  ℕ  ∧  𝑎  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑏  ∈  ( 𝔼 ‘ 𝑛 ) )  ∧  𝑎  ≠  𝑏 )  ∧  ( ( ( 𝑃  ∈  ( 𝑎 Line 𝑏 )  ∧  𝑄  ∈  ( 𝑎 Line 𝑏 ) )  ∧  𝑃  ≠  𝑎 )  ∧  ( 𝑃  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑄  ∈  ( 𝔼 ‘ 𝑛 ) ) ) )  →  𝑏  ∈  ( 𝔼 ‘ 𝑛 ) ) | 
						
							| 17 |  | simplr | ⊢ ( ( ( ( 𝑛  ∈  ℕ  ∧  𝑎  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑏  ∈  ( 𝔼 ‘ 𝑛 ) )  ∧  𝑎  ≠  𝑏 )  ∧  ( ( ( 𝑃  ∈  ( 𝑎 Line 𝑏 )  ∧  𝑄  ∈  ( 𝑎 Line 𝑏 ) )  ∧  𝑃  ≠  𝑎 )  ∧  ( 𝑃  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑄  ∈  ( 𝔼 ‘ 𝑛 ) ) ) )  →  𝑎  ≠  𝑏 ) | 
						
							| 18 |  | simprrl | ⊢ ( ( ( ( 𝑛  ∈  ℕ  ∧  𝑎  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑏  ∈  ( 𝔼 ‘ 𝑛 ) )  ∧  𝑎  ≠  𝑏 )  ∧  ( ( ( 𝑃  ∈  ( 𝑎 Line 𝑏 )  ∧  𝑄  ∈  ( 𝑎 Line 𝑏 ) )  ∧  𝑃  ≠  𝑎 )  ∧  ( 𝑃  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑄  ∈  ( 𝔼 ‘ 𝑛 ) ) ) )  →  𝑃  ∈  ( 𝔼 ‘ 𝑛 ) ) | 
						
							| 19 |  | simprlr | ⊢ ( ( ( ( 𝑛  ∈  ℕ  ∧  𝑎  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑏  ∈  ( 𝔼 ‘ 𝑛 ) )  ∧  𝑎  ≠  𝑏 )  ∧  ( ( ( 𝑃  ∈  ( 𝑎 Line 𝑏 )  ∧  𝑄  ∈  ( 𝑎 Line 𝑏 ) )  ∧  𝑃  ≠  𝑎 )  ∧  ( 𝑃  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑄  ∈  ( 𝔼 ‘ 𝑛 ) ) ) )  →  𝑃  ≠  𝑎 ) | 
						
							| 20 | 19 | necomd | ⊢ ( ( ( ( 𝑛  ∈  ℕ  ∧  𝑎  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑏  ∈  ( 𝔼 ‘ 𝑛 ) )  ∧  𝑎  ≠  𝑏 )  ∧  ( ( ( 𝑃  ∈  ( 𝑎 Line 𝑏 )  ∧  𝑄  ∈  ( 𝑎 Line 𝑏 ) )  ∧  𝑃  ≠  𝑎 )  ∧  ( 𝑃  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑄  ∈  ( 𝔼 ‘ 𝑛 ) ) ) )  →  𝑎  ≠  𝑃 ) | 
						
							| 21 |  | lineelsb2 | ⊢ ( ( 𝑛  ∈  ℕ  ∧  ( 𝑎  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑏  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑎  ≠  𝑏 )  ∧  ( 𝑃  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑎  ≠  𝑃 ) )  →  ( 𝑃  ∈  ( 𝑎 Line 𝑏 )  →  ( 𝑎 Line 𝑏 )  =  ( 𝑎 Line 𝑃 ) ) ) | 
						
							| 22 | 14 15 16 17 18 20 21 | syl132anc | ⊢ ( ( ( ( 𝑛  ∈  ℕ  ∧  𝑎  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑏  ∈  ( 𝔼 ‘ 𝑛 ) )  ∧  𝑎  ≠  𝑏 )  ∧  ( ( ( 𝑃  ∈  ( 𝑎 Line 𝑏 )  ∧  𝑄  ∈  ( 𝑎 Line 𝑏 ) )  ∧  𝑃  ≠  𝑎 )  ∧  ( 𝑃  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑄  ∈  ( 𝔼 ‘ 𝑛 ) ) ) )  →  ( 𝑃  ∈  ( 𝑎 Line 𝑏 )  →  ( 𝑎 Line 𝑏 )  =  ( 𝑎 Line 𝑃 ) ) ) | 
						
							| 23 | 13 22 | mpd | ⊢ ( ( ( ( 𝑛  ∈  ℕ  ∧  𝑎  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑏  ∈  ( 𝔼 ‘ 𝑛 ) )  ∧  𝑎  ≠  𝑏 )  ∧  ( ( ( 𝑃  ∈  ( 𝑎 Line 𝑏 )  ∧  𝑄  ∈  ( 𝑎 Line 𝑏 ) )  ∧  𝑃  ≠  𝑎 )  ∧  ( 𝑃  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑄  ∈  ( 𝔼 ‘ 𝑛 ) ) ) )  →  ( 𝑎 Line 𝑏 )  =  ( 𝑎 Line 𝑃 ) ) | 
						
							| 24 |  | linecom | ⊢ ( ( 𝑛  ∈  ℕ  ∧  ( 𝑎  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑃  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑎  ≠  𝑃 ) )  →  ( 𝑎 Line 𝑃 )  =  ( 𝑃 Line 𝑎 ) ) | 
						
							| 25 | 14 15 18 20 24 | syl13anc | ⊢ ( ( ( ( 𝑛  ∈  ℕ  ∧  𝑎  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑏  ∈  ( 𝔼 ‘ 𝑛 ) )  ∧  𝑎  ≠  𝑏 )  ∧  ( ( ( 𝑃  ∈  ( 𝑎 Line 𝑏 )  ∧  𝑄  ∈  ( 𝑎 Line 𝑏 ) )  ∧  𝑃  ≠  𝑎 )  ∧  ( 𝑃  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑄  ∈  ( 𝔼 ‘ 𝑛 ) ) ) )  →  ( 𝑎 Line 𝑃 )  =  ( 𝑃 Line 𝑎 ) ) | 
						
							| 26 | 23 25 | eqtrd | ⊢ ( ( ( ( 𝑛  ∈  ℕ  ∧  𝑎  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑏  ∈  ( 𝔼 ‘ 𝑛 ) )  ∧  𝑎  ≠  𝑏 )  ∧  ( ( ( 𝑃  ∈  ( 𝑎 Line 𝑏 )  ∧  𝑄  ∈  ( 𝑎 Line 𝑏 ) )  ∧  𝑃  ≠  𝑎 )  ∧  ( 𝑃  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑄  ∈  ( 𝔼 ‘ 𝑛 ) ) ) )  →  ( 𝑎 Line 𝑏 )  =  ( 𝑃 Line 𝑎 ) ) | 
						
							| 27 |  | neeq2 | ⊢ ( 𝑄  =  𝑎  →  ( 𝑃  ≠  𝑄  ↔  𝑃  ≠  𝑎 ) ) | 
						
							| 28 | 27 | anbi2d | ⊢ ( 𝑄  =  𝑎  →  ( ( ( 𝑃  ∈  ( 𝑎 Line 𝑏 )  ∧  𝑄  ∈  ( 𝑎 Line 𝑏 ) )  ∧  𝑃  ≠  𝑄 )  ↔  ( ( 𝑃  ∈  ( 𝑎 Line 𝑏 )  ∧  𝑄  ∈  ( 𝑎 Line 𝑏 ) )  ∧  𝑃  ≠  𝑎 ) ) ) | 
						
							| 29 | 28 | anbi1d | ⊢ ( 𝑄  =  𝑎  →  ( ( ( ( 𝑃  ∈  ( 𝑎 Line 𝑏 )  ∧  𝑄  ∈  ( 𝑎 Line 𝑏 ) )  ∧  𝑃  ≠  𝑄 )  ∧  ( 𝑃  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑄  ∈  ( 𝔼 ‘ 𝑛 ) ) )  ↔  ( ( ( 𝑃  ∈  ( 𝑎 Line 𝑏 )  ∧  𝑄  ∈  ( 𝑎 Line 𝑏 ) )  ∧  𝑃  ≠  𝑎 )  ∧  ( 𝑃  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑄  ∈  ( 𝔼 ‘ 𝑛 ) ) ) ) ) | 
						
							| 30 | 29 | anbi2d | ⊢ ( 𝑄  =  𝑎  →  ( ( ( ( 𝑛  ∈  ℕ  ∧  𝑎  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑏  ∈  ( 𝔼 ‘ 𝑛 ) )  ∧  𝑎  ≠  𝑏 )  ∧  ( ( ( 𝑃  ∈  ( 𝑎 Line 𝑏 )  ∧  𝑄  ∈  ( 𝑎 Line 𝑏 ) )  ∧  𝑃  ≠  𝑄 )  ∧  ( 𝑃  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑄  ∈  ( 𝔼 ‘ 𝑛 ) ) ) )  ↔  ( ( ( 𝑛  ∈  ℕ  ∧  𝑎  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑏  ∈  ( 𝔼 ‘ 𝑛 ) )  ∧  𝑎  ≠  𝑏 )  ∧  ( ( ( 𝑃  ∈  ( 𝑎 Line 𝑏 )  ∧  𝑄  ∈  ( 𝑎 Line 𝑏 ) )  ∧  𝑃  ≠  𝑎 )  ∧  ( 𝑃  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑄  ∈  ( 𝔼 ‘ 𝑛 ) ) ) ) ) ) | 
						
							| 31 |  | oveq2 | ⊢ ( 𝑄  =  𝑎  →  ( 𝑃 Line 𝑄 )  =  ( 𝑃 Line 𝑎 ) ) | 
						
							| 32 | 31 | eqeq2d | ⊢ ( 𝑄  =  𝑎  →  ( ( 𝑎 Line 𝑏 )  =  ( 𝑃 Line 𝑄 )  ↔  ( 𝑎 Line 𝑏 )  =  ( 𝑃 Line 𝑎 ) ) ) | 
						
							| 33 | 30 32 | imbi12d | ⊢ ( 𝑄  =  𝑎  →  ( ( ( ( ( 𝑛  ∈  ℕ  ∧  𝑎  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑏  ∈  ( 𝔼 ‘ 𝑛 ) )  ∧  𝑎  ≠  𝑏 )  ∧  ( ( ( 𝑃  ∈  ( 𝑎 Line 𝑏 )  ∧  𝑄  ∈  ( 𝑎 Line 𝑏 ) )  ∧  𝑃  ≠  𝑄 )  ∧  ( 𝑃  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑄  ∈  ( 𝔼 ‘ 𝑛 ) ) ) )  →  ( 𝑎 Line 𝑏 )  =  ( 𝑃 Line 𝑄 ) )  ↔  ( ( ( ( 𝑛  ∈  ℕ  ∧  𝑎  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑏  ∈  ( 𝔼 ‘ 𝑛 ) )  ∧  𝑎  ≠  𝑏 )  ∧  ( ( ( 𝑃  ∈  ( 𝑎 Line 𝑏 )  ∧  𝑄  ∈  ( 𝑎 Line 𝑏 ) )  ∧  𝑃  ≠  𝑎 )  ∧  ( 𝑃  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑄  ∈  ( 𝔼 ‘ 𝑛 ) ) ) )  →  ( 𝑎 Line 𝑏 )  =  ( 𝑃 Line 𝑎 ) ) ) ) | 
						
							| 34 | 26 33 | mpbiri | ⊢ ( 𝑄  =  𝑎  →  ( ( ( ( 𝑛  ∈  ℕ  ∧  𝑎  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑏  ∈  ( 𝔼 ‘ 𝑛 ) )  ∧  𝑎  ≠  𝑏 )  ∧  ( ( ( 𝑃  ∈  ( 𝑎 Line 𝑏 )  ∧  𝑄  ∈  ( 𝑎 Line 𝑏 ) )  ∧  𝑃  ≠  𝑄 )  ∧  ( 𝑃  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑄  ∈  ( 𝔼 ‘ 𝑛 ) ) ) )  →  ( 𝑎 Line 𝑏 )  =  ( 𝑃 Line 𝑄 ) ) ) | 
						
							| 35 |  | simp1 | ⊢ ( ( ( ( 𝑛  ∈  ℕ  ∧  𝑎  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑏  ∈  ( 𝔼 ‘ 𝑛 ) )  ∧  𝑎  ≠  𝑏 )  ∧  ( ( ( 𝑃  ∈  ( 𝑎 Line 𝑏 )  ∧  𝑄  ∈  ( 𝑎 Line 𝑏 ) )  ∧  𝑃  ≠  𝑄 )  ∧  ( 𝑃  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑄  ∈  ( 𝔼 ‘ 𝑛 ) ) )  ∧  𝑄  ≠  𝑎 )  →  ( ( 𝑛  ∈  ℕ  ∧  𝑎  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑏  ∈  ( 𝔼 ‘ 𝑛 ) )  ∧  𝑎  ≠  𝑏 ) ) | 
						
							| 36 |  | simp2l | ⊢ ( ( ( ( 𝑛  ∈  ℕ  ∧  𝑎  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑏  ∈  ( 𝔼 ‘ 𝑛 ) )  ∧  𝑎  ≠  𝑏 )  ∧  ( ( ( 𝑃  ∈  ( 𝑎 Line 𝑏 )  ∧  𝑄  ∈  ( 𝑎 Line 𝑏 ) )  ∧  𝑃  ≠  𝑄 )  ∧  ( 𝑃  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑄  ∈  ( 𝔼 ‘ 𝑛 ) ) )  ∧  𝑄  ≠  𝑎 )  →  ( ( 𝑃  ∈  ( 𝑎 Line 𝑏 )  ∧  𝑄  ∈  ( 𝑎 Line 𝑏 ) )  ∧  𝑃  ≠  𝑄 ) ) | 
						
							| 37 | 35 36 10 | syl2anc | ⊢ ( ( ( ( 𝑛  ∈  ℕ  ∧  𝑎  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑏  ∈  ( 𝔼 ‘ 𝑛 ) )  ∧  𝑎  ≠  𝑏 )  ∧  ( ( ( 𝑃  ∈  ( 𝑎 Line 𝑏 )  ∧  𝑄  ∈  ( 𝑎 Line 𝑏 ) )  ∧  𝑃  ≠  𝑄 )  ∧  ( 𝑃  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑄  ∈  ( 𝔼 ‘ 𝑛 ) ) )  ∧  𝑄  ≠  𝑎 )  →  𝑄  ∈  ( 𝑎 Line 𝑏 ) ) | 
						
							| 38 |  | simp1l1 | ⊢ ( ( ( ( 𝑛  ∈  ℕ  ∧  𝑎  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑏  ∈  ( 𝔼 ‘ 𝑛 ) )  ∧  𝑎  ≠  𝑏 )  ∧  ( ( ( 𝑃  ∈  ( 𝑎 Line 𝑏 )  ∧  𝑄  ∈  ( 𝑎 Line 𝑏 ) )  ∧  𝑃  ≠  𝑄 )  ∧  ( 𝑃  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑄  ∈  ( 𝔼 ‘ 𝑛 ) ) )  ∧  𝑄  ≠  𝑎 )  →  𝑛  ∈  ℕ ) | 
						
							| 39 |  | simp1l2 | ⊢ ( ( ( ( 𝑛  ∈  ℕ  ∧  𝑎  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑏  ∈  ( 𝔼 ‘ 𝑛 ) )  ∧  𝑎  ≠  𝑏 )  ∧  ( ( ( 𝑃  ∈  ( 𝑎 Line 𝑏 )  ∧  𝑄  ∈  ( 𝑎 Line 𝑏 ) )  ∧  𝑃  ≠  𝑄 )  ∧  ( 𝑃  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑄  ∈  ( 𝔼 ‘ 𝑛 ) ) )  ∧  𝑄  ≠  𝑎 )  →  𝑎  ∈  ( 𝔼 ‘ 𝑛 ) ) | 
						
							| 40 |  | simp1l3 | ⊢ ( ( ( ( 𝑛  ∈  ℕ  ∧  𝑎  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑏  ∈  ( 𝔼 ‘ 𝑛 ) )  ∧  𝑎  ≠  𝑏 )  ∧  ( ( ( 𝑃  ∈  ( 𝑎 Line 𝑏 )  ∧  𝑄  ∈  ( 𝑎 Line 𝑏 ) )  ∧  𝑃  ≠  𝑄 )  ∧  ( 𝑃  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑄  ∈  ( 𝔼 ‘ 𝑛 ) ) )  ∧  𝑄  ≠  𝑎 )  →  𝑏  ∈  ( 𝔼 ‘ 𝑛 ) ) | 
						
							| 41 |  | simp1r | ⊢ ( ( ( ( 𝑛  ∈  ℕ  ∧  𝑎  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑏  ∈  ( 𝔼 ‘ 𝑛 ) )  ∧  𝑎  ≠  𝑏 )  ∧  ( ( ( 𝑃  ∈  ( 𝑎 Line 𝑏 )  ∧  𝑄  ∈  ( 𝑎 Line 𝑏 ) )  ∧  𝑃  ≠  𝑄 )  ∧  ( 𝑃  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑄  ∈  ( 𝔼 ‘ 𝑛 ) ) )  ∧  𝑄  ≠  𝑎 )  →  𝑎  ≠  𝑏 ) | 
						
							| 42 |  | simp2rr | ⊢ ( ( ( ( 𝑛  ∈  ℕ  ∧  𝑎  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑏  ∈  ( 𝔼 ‘ 𝑛 ) )  ∧  𝑎  ≠  𝑏 )  ∧  ( ( ( 𝑃  ∈  ( 𝑎 Line 𝑏 )  ∧  𝑄  ∈  ( 𝑎 Line 𝑏 ) )  ∧  𝑃  ≠  𝑄 )  ∧  ( 𝑃  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑄  ∈  ( 𝔼 ‘ 𝑛 ) ) )  ∧  𝑄  ≠  𝑎 )  →  𝑄  ∈  ( 𝔼 ‘ 𝑛 ) ) | 
						
							| 43 |  | simp3 | ⊢ ( ( ( ( 𝑛  ∈  ℕ  ∧  𝑎  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑏  ∈  ( 𝔼 ‘ 𝑛 ) )  ∧  𝑎  ≠  𝑏 )  ∧  ( ( ( 𝑃  ∈  ( 𝑎 Line 𝑏 )  ∧  𝑄  ∈  ( 𝑎 Line 𝑏 ) )  ∧  𝑃  ≠  𝑄 )  ∧  ( 𝑃  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑄  ∈  ( 𝔼 ‘ 𝑛 ) ) )  ∧  𝑄  ≠  𝑎 )  →  𝑄  ≠  𝑎 ) | 
						
							| 44 | 43 | necomd | ⊢ ( ( ( ( 𝑛  ∈  ℕ  ∧  𝑎  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑏  ∈  ( 𝔼 ‘ 𝑛 ) )  ∧  𝑎  ≠  𝑏 )  ∧  ( ( ( 𝑃  ∈  ( 𝑎 Line 𝑏 )  ∧  𝑄  ∈  ( 𝑎 Line 𝑏 ) )  ∧  𝑃  ≠  𝑄 )  ∧  ( 𝑃  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑄  ∈  ( 𝔼 ‘ 𝑛 ) ) )  ∧  𝑄  ≠  𝑎 )  →  𝑎  ≠  𝑄 ) | 
						
							| 45 |  | lineelsb2 | ⊢ ( ( 𝑛  ∈  ℕ  ∧  ( 𝑎  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑏  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑎  ≠  𝑏 )  ∧  ( 𝑄  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑎  ≠  𝑄 ) )  →  ( 𝑄  ∈  ( 𝑎 Line 𝑏 )  →  ( 𝑎 Line 𝑏 )  =  ( 𝑎 Line 𝑄 ) ) ) | 
						
							| 46 | 38 39 40 41 42 44 45 | syl132anc | ⊢ ( ( ( ( 𝑛  ∈  ℕ  ∧  𝑎  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑏  ∈  ( 𝔼 ‘ 𝑛 ) )  ∧  𝑎  ≠  𝑏 )  ∧  ( ( ( 𝑃  ∈  ( 𝑎 Line 𝑏 )  ∧  𝑄  ∈  ( 𝑎 Line 𝑏 ) )  ∧  𝑃  ≠  𝑄 )  ∧  ( 𝑃  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑄  ∈  ( 𝔼 ‘ 𝑛 ) ) )  ∧  𝑄  ≠  𝑎 )  →  ( 𝑄  ∈  ( 𝑎 Line 𝑏 )  →  ( 𝑎 Line 𝑏 )  =  ( 𝑎 Line 𝑄 ) ) ) | 
						
							| 47 | 37 46 | mpd | ⊢ ( ( ( ( 𝑛  ∈  ℕ  ∧  𝑎  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑏  ∈  ( 𝔼 ‘ 𝑛 ) )  ∧  𝑎  ≠  𝑏 )  ∧  ( ( ( 𝑃  ∈  ( 𝑎 Line 𝑏 )  ∧  𝑄  ∈  ( 𝑎 Line 𝑏 ) )  ∧  𝑃  ≠  𝑄 )  ∧  ( 𝑃  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑄  ∈  ( 𝔼 ‘ 𝑛 ) ) )  ∧  𝑄  ≠  𝑎 )  →  ( 𝑎 Line 𝑏 )  =  ( 𝑎 Line 𝑄 ) ) | 
						
							| 48 |  | linecom | ⊢ ( ( 𝑛  ∈  ℕ  ∧  ( 𝑎  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑄  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑎  ≠  𝑄 ) )  →  ( 𝑎 Line 𝑄 )  =  ( 𝑄 Line 𝑎 ) ) | 
						
							| 49 | 38 39 42 44 48 | syl13anc | ⊢ ( ( ( ( 𝑛  ∈  ℕ  ∧  𝑎  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑏  ∈  ( 𝔼 ‘ 𝑛 ) )  ∧  𝑎  ≠  𝑏 )  ∧  ( ( ( 𝑃  ∈  ( 𝑎 Line 𝑏 )  ∧  𝑄  ∈  ( 𝑎 Line 𝑏 ) )  ∧  𝑃  ≠  𝑄 )  ∧  ( 𝑃  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑄  ∈  ( 𝔼 ‘ 𝑛 ) ) )  ∧  𝑄  ≠  𝑎 )  →  ( 𝑎 Line 𝑄 )  =  ( 𝑄 Line 𝑎 ) ) | 
						
							| 50 | 47 49 | eqtrd | ⊢ ( ( ( ( 𝑛  ∈  ℕ  ∧  𝑎  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑏  ∈  ( 𝔼 ‘ 𝑛 ) )  ∧  𝑎  ≠  𝑏 )  ∧  ( ( ( 𝑃  ∈  ( 𝑎 Line 𝑏 )  ∧  𝑄  ∈  ( 𝑎 Line 𝑏 ) )  ∧  𝑃  ≠  𝑄 )  ∧  ( 𝑃  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑄  ∈  ( 𝔼 ‘ 𝑛 ) ) )  ∧  𝑄  ≠  𝑎 )  →  ( 𝑎 Line 𝑏 )  =  ( 𝑄 Line 𝑎 ) ) | 
						
							| 51 | 36 | simplld | ⊢ ( ( ( ( 𝑛  ∈  ℕ  ∧  𝑎  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑏  ∈  ( 𝔼 ‘ 𝑛 ) )  ∧  𝑎  ≠  𝑏 )  ∧  ( ( ( 𝑃  ∈  ( 𝑎 Line 𝑏 )  ∧  𝑄  ∈  ( 𝑎 Line 𝑏 ) )  ∧  𝑃  ≠  𝑄 )  ∧  ( 𝑃  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑄  ∈  ( 𝔼 ‘ 𝑛 ) ) )  ∧  𝑄  ≠  𝑎 )  →  𝑃  ∈  ( 𝑎 Line 𝑏 ) ) | 
						
							| 52 | 51 50 | eleqtrd | ⊢ ( ( ( ( 𝑛  ∈  ℕ  ∧  𝑎  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑏  ∈  ( 𝔼 ‘ 𝑛 ) )  ∧  𝑎  ≠  𝑏 )  ∧  ( ( ( 𝑃  ∈  ( 𝑎 Line 𝑏 )  ∧  𝑄  ∈  ( 𝑎 Line 𝑏 ) )  ∧  𝑃  ≠  𝑄 )  ∧  ( 𝑃  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑄  ∈  ( 𝔼 ‘ 𝑛 ) ) )  ∧  𝑄  ≠  𝑎 )  →  𝑃  ∈  ( 𝑄 Line 𝑎 ) ) | 
						
							| 53 |  | simp2rl | ⊢ ( ( ( ( 𝑛  ∈  ℕ  ∧  𝑎  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑏  ∈  ( 𝔼 ‘ 𝑛 ) )  ∧  𝑎  ≠  𝑏 )  ∧  ( ( ( 𝑃  ∈  ( 𝑎 Line 𝑏 )  ∧  𝑄  ∈  ( 𝑎 Line 𝑏 ) )  ∧  𝑃  ≠  𝑄 )  ∧  ( 𝑃  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑄  ∈  ( 𝔼 ‘ 𝑛 ) ) )  ∧  𝑄  ≠  𝑎 )  →  𝑃  ∈  ( 𝔼 ‘ 𝑛 ) ) | 
						
							| 54 |  | simp2lr | ⊢ ( ( ( ( 𝑛  ∈  ℕ  ∧  𝑎  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑏  ∈  ( 𝔼 ‘ 𝑛 ) )  ∧  𝑎  ≠  𝑏 )  ∧  ( ( ( 𝑃  ∈  ( 𝑎 Line 𝑏 )  ∧  𝑄  ∈  ( 𝑎 Line 𝑏 ) )  ∧  𝑃  ≠  𝑄 )  ∧  ( 𝑃  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑄  ∈  ( 𝔼 ‘ 𝑛 ) ) )  ∧  𝑄  ≠  𝑎 )  →  𝑃  ≠  𝑄 ) | 
						
							| 55 | 54 | necomd | ⊢ ( ( ( ( 𝑛  ∈  ℕ  ∧  𝑎  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑏  ∈  ( 𝔼 ‘ 𝑛 ) )  ∧  𝑎  ≠  𝑏 )  ∧  ( ( ( 𝑃  ∈  ( 𝑎 Line 𝑏 )  ∧  𝑄  ∈  ( 𝑎 Line 𝑏 ) )  ∧  𝑃  ≠  𝑄 )  ∧  ( 𝑃  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑄  ∈  ( 𝔼 ‘ 𝑛 ) ) )  ∧  𝑄  ≠  𝑎 )  →  𝑄  ≠  𝑃 ) | 
						
							| 56 |  | lineelsb2 | ⊢ ( ( 𝑛  ∈  ℕ  ∧  ( 𝑄  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑎  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑄  ≠  𝑎 )  ∧  ( 𝑃  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑄  ≠  𝑃 ) )  →  ( 𝑃  ∈  ( 𝑄 Line 𝑎 )  →  ( 𝑄 Line 𝑎 )  =  ( 𝑄 Line 𝑃 ) ) ) | 
						
							| 57 | 38 42 39 43 53 55 56 | syl132anc | ⊢ ( ( ( ( 𝑛  ∈  ℕ  ∧  𝑎  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑏  ∈  ( 𝔼 ‘ 𝑛 ) )  ∧  𝑎  ≠  𝑏 )  ∧  ( ( ( 𝑃  ∈  ( 𝑎 Line 𝑏 )  ∧  𝑄  ∈  ( 𝑎 Line 𝑏 ) )  ∧  𝑃  ≠  𝑄 )  ∧  ( 𝑃  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑄  ∈  ( 𝔼 ‘ 𝑛 ) ) )  ∧  𝑄  ≠  𝑎 )  →  ( 𝑃  ∈  ( 𝑄 Line 𝑎 )  →  ( 𝑄 Line 𝑎 )  =  ( 𝑄 Line 𝑃 ) ) ) | 
						
							| 58 | 52 57 | mpd | ⊢ ( ( ( ( 𝑛  ∈  ℕ  ∧  𝑎  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑏  ∈  ( 𝔼 ‘ 𝑛 ) )  ∧  𝑎  ≠  𝑏 )  ∧  ( ( ( 𝑃  ∈  ( 𝑎 Line 𝑏 )  ∧  𝑄  ∈  ( 𝑎 Line 𝑏 ) )  ∧  𝑃  ≠  𝑄 )  ∧  ( 𝑃  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑄  ∈  ( 𝔼 ‘ 𝑛 ) ) )  ∧  𝑄  ≠  𝑎 )  →  ( 𝑄 Line 𝑎 )  =  ( 𝑄 Line 𝑃 ) ) | 
						
							| 59 |  | linecom | ⊢ ( ( 𝑛  ∈  ℕ  ∧  ( 𝑄  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑃  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑄  ≠  𝑃 ) )  →  ( 𝑄 Line 𝑃 )  =  ( 𝑃 Line 𝑄 ) ) | 
						
							| 60 | 38 42 53 55 59 | syl13anc | ⊢ ( ( ( ( 𝑛  ∈  ℕ  ∧  𝑎  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑏  ∈  ( 𝔼 ‘ 𝑛 ) )  ∧  𝑎  ≠  𝑏 )  ∧  ( ( ( 𝑃  ∈  ( 𝑎 Line 𝑏 )  ∧  𝑄  ∈  ( 𝑎 Line 𝑏 ) )  ∧  𝑃  ≠  𝑄 )  ∧  ( 𝑃  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑄  ∈  ( 𝔼 ‘ 𝑛 ) ) )  ∧  𝑄  ≠  𝑎 )  →  ( 𝑄 Line 𝑃 )  =  ( 𝑃 Line 𝑄 ) ) | 
						
							| 61 | 50 58 60 | 3eqtrd | ⊢ ( ( ( ( 𝑛  ∈  ℕ  ∧  𝑎  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑏  ∈  ( 𝔼 ‘ 𝑛 ) )  ∧  𝑎  ≠  𝑏 )  ∧  ( ( ( 𝑃  ∈  ( 𝑎 Line 𝑏 )  ∧  𝑄  ∈  ( 𝑎 Line 𝑏 ) )  ∧  𝑃  ≠  𝑄 )  ∧  ( 𝑃  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑄  ∈  ( 𝔼 ‘ 𝑛 ) ) )  ∧  𝑄  ≠  𝑎 )  →  ( 𝑎 Line 𝑏 )  =  ( 𝑃 Line 𝑄 ) ) | 
						
							| 62 | 61 | 3expa | ⊢ ( ( ( ( ( 𝑛  ∈  ℕ  ∧  𝑎  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑏  ∈  ( 𝔼 ‘ 𝑛 ) )  ∧  𝑎  ≠  𝑏 )  ∧  ( ( ( 𝑃  ∈  ( 𝑎 Line 𝑏 )  ∧  𝑄  ∈  ( 𝑎 Line 𝑏 ) )  ∧  𝑃  ≠  𝑄 )  ∧  ( 𝑃  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑄  ∈  ( 𝔼 ‘ 𝑛 ) ) ) )  ∧  𝑄  ≠  𝑎 )  →  ( 𝑎 Line 𝑏 )  =  ( 𝑃 Line 𝑄 ) ) | 
						
							| 63 | 62 | expcom | ⊢ ( 𝑄  ≠  𝑎  →  ( ( ( ( 𝑛  ∈  ℕ  ∧  𝑎  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑏  ∈  ( 𝔼 ‘ 𝑛 ) )  ∧  𝑎  ≠  𝑏 )  ∧  ( ( ( 𝑃  ∈  ( 𝑎 Line 𝑏 )  ∧  𝑄  ∈  ( 𝑎 Line 𝑏 ) )  ∧  𝑃  ≠  𝑄 )  ∧  ( 𝑃  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑄  ∈  ( 𝔼 ‘ 𝑛 ) ) ) )  →  ( 𝑎 Line 𝑏 )  =  ( 𝑃 Line 𝑄 ) ) ) | 
						
							| 64 | 34 63 | pm2.61ine | ⊢ ( ( ( ( 𝑛  ∈  ℕ  ∧  𝑎  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑏  ∈  ( 𝔼 ‘ 𝑛 ) )  ∧  𝑎  ≠  𝑏 )  ∧  ( ( ( 𝑃  ∈  ( 𝑎 Line 𝑏 )  ∧  𝑄  ∈  ( 𝑎 Line 𝑏 ) )  ∧  𝑃  ≠  𝑄 )  ∧  ( 𝑃  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑄  ∈  ( 𝔼 ‘ 𝑛 ) ) ) )  →  ( 𝑎 Line 𝑏 )  =  ( 𝑃 Line 𝑄 ) ) | 
						
							| 65 | 64 | expr | ⊢ ( ( ( ( 𝑛  ∈  ℕ  ∧  𝑎  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑏  ∈  ( 𝔼 ‘ 𝑛 ) )  ∧  𝑎  ≠  𝑏 )  ∧  ( ( 𝑃  ∈  ( 𝑎 Line 𝑏 )  ∧  𝑄  ∈  ( 𝑎 Line 𝑏 ) )  ∧  𝑃  ≠  𝑄 ) )  →  ( ( 𝑃  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑄  ∈  ( 𝔼 ‘ 𝑛 ) )  →  ( 𝑎 Line 𝑏 )  =  ( 𝑃 Line 𝑄 ) ) ) | 
						
							| 66 | 9 11 65 | mp2and | ⊢ ( ( ( ( 𝑛  ∈  ℕ  ∧  𝑎  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑏  ∈  ( 𝔼 ‘ 𝑛 ) )  ∧  𝑎  ≠  𝑏 )  ∧  ( ( 𝑃  ∈  ( 𝑎 Line 𝑏 )  ∧  𝑄  ∈  ( 𝑎 Line 𝑏 ) )  ∧  𝑃  ≠  𝑄 ) )  →  ( 𝑎 Line 𝑏 )  =  ( 𝑃 Line 𝑄 ) ) | 
						
							| 67 | 66 | ex | ⊢ ( ( ( 𝑛  ∈  ℕ  ∧  𝑎  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑏  ∈  ( 𝔼 ‘ 𝑛 ) )  ∧  𝑎  ≠  𝑏 )  →  ( ( ( 𝑃  ∈  ( 𝑎 Line 𝑏 )  ∧  𝑄  ∈  ( 𝑎 Line 𝑏 ) )  ∧  𝑃  ≠  𝑄 )  →  ( 𝑎 Line 𝑏 )  =  ( 𝑃 Line 𝑄 ) ) ) | 
						
							| 68 |  | eleq2 | ⊢ ( 𝐴  =  ( 𝑎 Line 𝑏 )  →  ( 𝑃  ∈  𝐴  ↔  𝑃  ∈  ( 𝑎 Line 𝑏 ) ) ) | 
						
							| 69 |  | eleq2 | ⊢ ( 𝐴  =  ( 𝑎 Line 𝑏 )  →  ( 𝑄  ∈  𝐴  ↔  𝑄  ∈  ( 𝑎 Line 𝑏 ) ) ) | 
						
							| 70 | 68 69 | anbi12d | ⊢ ( 𝐴  =  ( 𝑎 Line 𝑏 )  →  ( ( 𝑃  ∈  𝐴  ∧  𝑄  ∈  𝐴 )  ↔  ( 𝑃  ∈  ( 𝑎 Line 𝑏 )  ∧  𝑄  ∈  ( 𝑎 Line 𝑏 ) ) ) ) | 
						
							| 71 | 70 | anbi1d | ⊢ ( 𝐴  =  ( 𝑎 Line 𝑏 )  →  ( ( ( 𝑃  ∈  𝐴  ∧  𝑄  ∈  𝐴 )  ∧  𝑃  ≠  𝑄 )  ↔  ( ( 𝑃  ∈  ( 𝑎 Line 𝑏 )  ∧  𝑄  ∈  ( 𝑎 Line 𝑏 ) )  ∧  𝑃  ≠  𝑄 ) ) ) | 
						
							| 72 |  | eqeq1 | ⊢ ( 𝐴  =  ( 𝑎 Line 𝑏 )  →  ( 𝐴  =  ( 𝑃 Line 𝑄 )  ↔  ( 𝑎 Line 𝑏 )  =  ( 𝑃 Line 𝑄 ) ) ) | 
						
							| 73 | 71 72 | imbi12d | ⊢ ( 𝐴  =  ( 𝑎 Line 𝑏 )  →  ( ( ( ( 𝑃  ∈  𝐴  ∧  𝑄  ∈  𝐴 )  ∧  𝑃  ≠  𝑄 )  →  𝐴  =  ( 𝑃 Line 𝑄 ) )  ↔  ( ( ( 𝑃  ∈  ( 𝑎 Line 𝑏 )  ∧  𝑄  ∈  ( 𝑎 Line 𝑏 ) )  ∧  𝑃  ≠  𝑄 )  →  ( 𝑎 Line 𝑏 )  =  ( 𝑃 Line 𝑄 ) ) ) ) | 
						
							| 74 | 67 73 | syl5ibrcom | ⊢ ( ( ( 𝑛  ∈  ℕ  ∧  𝑎  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑏  ∈  ( 𝔼 ‘ 𝑛 ) )  ∧  𝑎  ≠  𝑏 )  →  ( 𝐴  =  ( 𝑎 Line 𝑏 )  →  ( ( ( 𝑃  ∈  𝐴  ∧  𝑄  ∈  𝐴 )  ∧  𝑃  ≠  𝑄 )  →  𝐴  =  ( 𝑃 Line 𝑄 ) ) ) ) | 
						
							| 75 | 74 | expimpd | ⊢ ( ( 𝑛  ∈  ℕ  ∧  𝑎  ∈  ( 𝔼 ‘ 𝑛 )  ∧  𝑏  ∈  ( 𝔼 ‘ 𝑛 ) )  →  ( ( 𝑎  ≠  𝑏  ∧  𝐴  =  ( 𝑎 Line 𝑏 ) )  →  ( ( ( 𝑃  ∈  𝐴  ∧  𝑄  ∈  𝐴 )  ∧  𝑃  ≠  𝑄 )  →  𝐴  =  ( 𝑃 Line 𝑄 ) ) ) ) | 
						
							| 76 | 75 | 3expa | ⊢ ( ( ( 𝑛  ∈  ℕ  ∧  𝑎  ∈  ( 𝔼 ‘ 𝑛 ) )  ∧  𝑏  ∈  ( 𝔼 ‘ 𝑛 ) )  →  ( ( 𝑎  ≠  𝑏  ∧  𝐴  =  ( 𝑎 Line 𝑏 ) )  →  ( ( ( 𝑃  ∈  𝐴  ∧  𝑄  ∈  𝐴 )  ∧  𝑃  ≠  𝑄 )  →  𝐴  =  ( 𝑃 Line 𝑄 ) ) ) ) | 
						
							| 77 | 76 | rexlimdva | ⊢ ( ( 𝑛  ∈  ℕ  ∧  𝑎  ∈  ( 𝔼 ‘ 𝑛 ) )  →  ( ∃ 𝑏  ∈  ( 𝔼 ‘ 𝑛 ) ( 𝑎  ≠  𝑏  ∧  𝐴  =  ( 𝑎 Line 𝑏 ) )  →  ( ( ( 𝑃  ∈  𝐴  ∧  𝑄  ∈  𝐴 )  ∧  𝑃  ≠  𝑄 )  →  𝐴  =  ( 𝑃 Line 𝑄 ) ) ) ) | 
						
							| 78 | 77 | rexlimivv | ⊢ ( ∃ 𝑛  ∈  ℕ ∃ 𝑎  ∈  ( 𝔼 ‘ 𝑛 ) ∃ 𝑏  ∈  ( 𝔼 ‘ 𝑛 ) ( 𝑎  ≠  𝑏  ∧  𝐴  =  ( 𝑎 Line 𝑏 ) )  →  ( ( ( 𝑃  ∈  𝐴  ∧  𝑄  ∈  𝐴 )  ∧  𝑃  ≠  𝑄 )  →  𝐴  =  ( 𝑃 Line 𝑄 ) ) ) | 
						
							| 79 | 1 78 | sylbi | ⊢ ( 𝐴  ∈  LinesEE  →  ( ( ( 𝑃  ∈  𝐴  ∧  𝑄  ∈  𝐴 )  ∧  𝑃  ≠  𝑄 )  →  𝐴  =  ( 𝑃 Line 𝑄 ) ) ) | 
						
							| 80 | 79 | 3impib | ⊢ ( ( 𝐴  ∈  LinesEE  ∧  ( 𝑃  ∈  𝐴  ∧  𝑄  ∈  𝐴 )  ∧  𝑃  ≠  𝑄 )  →  𝐴  =  ( 𝑃 Line 𝑄 ) ) |