| Step | 
						Hyp | 
						Ref | 
						Expression | 
					
						
							| 1 | 
							
								
							 | 
							isline3.b | 
							⊢ 𝐵  =  ( Base ‘ 𝐾 )  | 
						
						
							| 2 | 
							
								
							 | 
							isline3.j | 
							⊢  ∨   =  ( join ‘ 𝐾 )  | 
						
						
							| 3 | 
							
								
							 | 
							isline3.a | 
							⊢ 𝐴  =  ( Atoms ‘ 𝐾 )  | 
						
						
							| 4 | 
							
								
							 | 
							isline3.n | 
							⊢ 𝑁  =  ( Lines ‘ 𝐾 )  | 
						
						
							| 5 | 
							
								
							 | 
							isline3.m | 
							⊢ 𝑀  =  ( pmap ‘ 𝐾 )  | 
						
						
							| 6 | 
							
								
							 | 
							hllat | 
							⊢ ( 𝐾  ∈  HL  →  𝐾  ∈  Lat )  | 
						
						
							| 7 | 
							
								6
							 | 
							adantr | 
							⊢ ( ( 𝐾  ∈  HL  ∧  𝑋  ∈  𝐵 )  →  𝐾  ∈  Lat )  | 
						
						
							| 8 | 
							
								2 3 4 5
							 | 
							isline2 | 
							⊢ ( 𝐾  ∈  Lat  →  ( ( 𝑀 ‘ 𝑋 )  ∈  𝑁  ↔  ∃ 𝑝  ∈  𝐴 ∃ 𝑞  ∈  𝐴 ( 𝑝  ≠  𝑞  ∧  ( 𝑀 ‘ 𝑋 )  =  ( 𝑀 ‘ ( 𝑝  ∨  𝑞 ) ) ) ) )  | 
						
						
							| 9 | 
							
								7 8
							 | 
							syl | 
							⊢ ( ( 𝐾  ∈  HL  ∧  𝑋  ∈  𝐵 )  →  ( ( 𝑀 ‘ 𝑋 )  ∈  𝑁  ↔  ∃ 𝑝  ∈  𝐴 ∃ 𝑞  ∈  𝐴 ( 𝑝  ≠  𝑞  ∧  ( 𝑀 ‘ 𝑋 )  =  ( 𝑀 ‘ ( 𝑝  ∨  𝑞 ) ) ) ) )  | 
						
						
							| 10 | 
							
								
							 | 
							simpll | 
							⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑋  ∈  𝐵 )  ∧  ( 𝑝  ∈  𝐴  ∧  𝑞  ∈  𝐴 ) )  →  𝐾  ∈  HL )  | 
						
						
							| 11 | 
							
								
							 | 
							simplr | 
							⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑋  ∈  𝐵 )  ∧  ( 𝑝  ∈  𝐴  ∧  𝑞  ∈  𝐴 ) )  →  𝑋  ∈  𝐵 )  | 
						
						
							| 12 | 
							
								6
							 | 
							ad2antrr | 
							⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑋  ∈  𝐵 )  ∧  ( 𝑝  ∈  𝐴  ∧  𝑞  ∈  𝐴 ) )  →  𝐾  ∈  Lat )  | 
						
						
							| 13 | 
							
								1 3
							 | 
							atbase | 
							⊢ ( 𝑝  ∈  𝐴  →  𝑝  ∈  𝐵 )  | 
						
						
							| 14 | 
							
								13
							 | 
							ad2antrl | 
							⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑋  ∈  𝐵 )  ∧  ( 𝑝  ∈  𝐴  ∧  𝑞  ∈  𝐴 ) )  →  𝑝  ∈  𝐵 )  | 
						
						
							| 15 | 
							
								1 3
							 | 
							atbase | 
							⊢ ( 𝑞  ∈  𝐴  →  𝑞  ∈  𝐵 )  | 
						
						
							| 16 | 
							
								15
							 | 
							ad2antll | 
							⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑋  ∈  𝐵 )  ∧  ( 𝑝  ∈  𝐴  ∧  𝑞  ∈  𝐴 ) )  →  𝑞  ∈  𝐵 )  | 
						
						
							| 17 | 
							
								1 2
							 | 
							latjcl | 
							⊢ ( ( 𝐾  ∈  Lat  ∧  𝑝  ∈  𝐵  ∧  𝑞  ∈  𝐵 )  →  ( 𝑝  ∨  𝑞 )  ∈  𝐵 )  | 
						
						
							| 18 | 
							
								12 14 16 17
							 | 
							syl3anc | 
							⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑋  ∈  𝐵 )  ∧  ( 𝑝  ∈  𝐴  ∧  𝑞  ∈  𝐴 ) )  →  ( 𝑝  ∨  𝑞 )  ∈  𝐵 )  | 
						
						
							| 19 | 
							
								1 5
							 | 
							pmap11 | 
							⊢ ( ( 𝐾  ∈  HL  ∧  𝑋  ∈  𝐵  ∧  ( 𝑝  ∨  𝑞 )  ∈  𝐵 )  →  ( ( 𝑀 ‘ 𝑋 )  =  ( 𝑀 ‘ ( 𝑝  ∨  𝑞 ) )  ↔  𝑋  =  ( 𝑝  ∨  𝑞 ) ) )  | 
						
						
							| 20 | 
							
								10 11 18 19
							 | 
							syl3anc | 
							⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑋  ∈  𝐵 )  ∧  ( 𝑝  ∈  𝐴  ∧  𝑞  ∈  𝐴 ) )  →  ( ( 𝑀 ‘ 𝑋 )  =  ( 𝑀 ‘ ( 𝑝  ∨  𝑞 ) )  ↔  𝑋  =  ( 𝑝  ∨  𝑞 ) ) )  | 
						
						
							| 21 | 
							
								20
							 | 
							anbi2d | 
							⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑋  ∈  𝐵 )  ∧  ( 𝑝  ∈  𝐴  ∧  𝑞  ∈  𝐴 ) )  →  ( ( 𝑝  ≠  𝑞  ∧  ( 𝑀 ‘ 𝑋 )  =  ( 𝑀 ‘ ( 𝑝  ∨  𝑞 ) ) )  ↔  ( 𝑝  ≠  𝑞  ∧  𝑋  =  ( 𝑝  ∨  𝑞 ) ) ) )  | 
						
						
							| 22 | 
							
								21
							 | 
							2rexbidva | 
							⊢ ( ( 𝐾  ∈  HL  ∧  𝑋  ∈  𝐵 )  →  ( ∃ 𝑝  ∈  𝐴 ∃ 𝑞  ∈  𝐴 ( 𝑝  ≠  𝑞  ∧  ( 𝑀 ‘ 𝑋 )  =  ( 𝑀 ‘ ( 𝑝  ∨  𝑞 ) ) )  ↔  ∃ 𝑝  ∈  𝐴 ∃ 𝑞  ∈  𝐴 ( 𝑝  ≠  𝑞  ∧  𝑋  =  ( 𝑝  ∨  𝑞 ) ) ) )  | 
						
						
							| 23 | 
							
								9 22
							 | 
							bitrd | 
							⊢ ( ( 𝐾  ∈  HL  ∧  𝑋  ∈  𝐵 )  →  ( ( 𝑀 ‘ 𝑋 )  ∈  𝑁  ↔  ∃ 𝑝  ∈  𝐴 ∃ 𝑞  ∈  𝐴 ( 𝑝  ≠  𝑞  ∧  𝑋  =  ( 𝑝  ∨  𝑞 ) ) ) )  |