| Step | Hyp | Ref | Expression | 
						
							| 1 |  | cdlema2.b | ⊢ 𝐵  =  ( Base ‘ 𝐾 ) | 
						
							| 2 |  | cdlema2.l | ⊢  ≤   =  ( le ‘ 𝐾 ) | 
						
							| 3 |  | cdlema2.j | ⊢  ∨   =  ( join ‘ 𝐾 ) | 
						
							| 4 |  | cdlema2.m | ⊢  ∧   =  ( meet ‘ 𝐾 ) | 
						
							| 5 |  | cdlema2.z | ⊢  0   =  ( 0. ‘ 𝐾 ) | 
						
							| 6 |  | cdlema2.a | ⊢ 𝐴  =  ( Atoms ‘ 𝐾 ) | 
						
							| 7 |  | simp3ll | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑋  ∈  𝐵 )  ∧  ( 𝑃  ∈  𝐴  ∧  𝑄  ∈  𝐴  ∧  𝑅  ∈  𝐴 )  ∧  ( ( 𝑅  ≠  𝑃  ∧  𝑅  ≤  ( 𝑃  ∨  𝑄 ) )  ∧  ( 𝑃  ≤  𝑋  ∧  ¬  𝑄  ≤  𝑋 ) ) )  →  𝑅  ≠  𝑃 ) | 
						
							| 8 |  | simp3rl | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑋  ∈  𝐵 )  ∧  ( 𝑃  ∈  𝐴  ∧  𝑄  ∈  𝐴  ∧  𝑅  ∈  𝐴 )  ∧  ( ( 𝑅  ≠  𝑃  ∧  𝑅  ≤  ( 𝑃  ∨  𝑄 ) )  ∧  ( 𝑃  ≤  𝑋  ∧  ¬  𝑄  ≤  𝑋 ) ) )  →  𝑃  ≤  𝑋 ) | 
						
							| 9 |  | simp3rr | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑋  ∈  𝐵 )  ∧  ( 𝑃  ∈  𝐴  ∧  𝑄  ∈  𝐴  ∧  𝑅  ∈  𝐴 )  ∧  ( ( 𝑅  ≠  𝑃  ∧  𝑅  ≤  ( 𝑃  ∨  𝑄 ) )  ∧  ( 𝑃  ≤  𝑋  ∧  ¬  𝑄  ≤  𝑋 ) ) )  →  ¬  𝑄  ≤  𝑋 ) | 
						
							| 10 |  | simp3lr | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑋  ∈  𝐵 )  ∧  ( 𝑃  ∈  𝐴  ∧  𝑄  ∈  𝐴  ∧  𝑅  ∈  𝐴 )  ∧  ( ( 𝑅  ≠  𝑃  ∧  𝑅  ≤  ( 𝑃  ∨  𝑄 ) )  ∧  ( 𝑃  ≤  𝑋  ∧  ¬  𝑄  ≤  𝑋 ) ) )  →  𝑅  ≤  ( 𝑃  ∨  𝑄 ) ) | 
						
							| 11 | 8 9 10 | 3jca | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑋  ∈  𝐵 )  ∧  ( 𝑃  ∈  𝐴  ∧  𝑄  ∈  𝐴  ∧  𝑅  ∈  𝐴 )  ∧  ( ( 𝑅  ≠  𝑃  ∧  𝑅  ≤  ( 𝑃  ∨  𝑄 ) )  ∧  ( 𝑃  ≤  𝑋  ∧  ¬  𝑄  ≤  𝑋 ) ) )  →  ( 𝑃  ≤  𝑋  ∧  ¬  𝑄  ≤  𝑋  ∧  𝑅  ≤  ( 𝑃  ∨  𝑄 ) ) ) | 
						
							| 12 | 1 2 3 6 | exatleN | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑋  ∈  𝐵 )  ∧  ( 𝑃  ∈  𝐴  ∧  𝑄  ∈  𝐴  ∧  𝑅  ∈  𝐴 )  ∧  ( 𝑃  ≤  𝑋  ∧  ¬  𝑄  ≤  𝑋  ∧  𝑅  ≤  ( 𝑃  ∨  𝑄 ) ) )  →  ( 𝑅  ≤  𝑋  ↔  𝑅  =  𝑃 ) ) | 
						
							| 13 | 11 12 | syld3an3 | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑋  ∈  𝐵 )  ∧  ( 𝑃  ∈  𝐴  ∧  𝑄  ∈  𝐴  ∧  𝑅  ∈  𝐴 )  ∧  ( ( 𝑅  ≠  𝑃  ∧  𝑅  ≤  ( 𝑃  ∨  𝑄 ) )  ∧  ( 𝑃  ≤  𝑋  ∧  ¬  𝑄  ≤  𝑋 ) ) )  →  ( 𝑅  ≤  𝑋  ↔  𝑅  =  𝑃 ) ) | 
						
							| 14 | 13 | necon3bbid | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑋  ∈  𝐵 )  ∧  ( 𝑃  ∈  𝐴  ∧  𝑄  ∈  𝐴  ∧  𝑅  ∈  𝐴 )  ∧  ( ( 𝑅  ≠  𝑃  ∧  𝑅  ≤  ( 𝑃  ∨  𝑄 ) )  ∧  ( 𝑃  ≤  𝑋  ∧  ¬  𝑄  ≤  𝑋 ) ) )  →  ( ¬  𝑅  ≤  𝑋  ↔  𝑅  ≠  𝑃 ) ) | 
						
							| 15 | 7 14 | mpbird | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑋  ∈  𝐵 )  ∧  ( 𝑃  ∈  𝐴  ∧  𝑄  ∈  𝐴  ∧  𝑅  ∈  𝐴 )  ∧  ( ( 𝑅  ≠  𝑃  ∧  𝑅  ≤  ( 𝑃  ∨  𝑄 ) )  ∧  ( 𝑃  ≤  𝑋  ∧  ¬  𝑄  ≤  𝑋 ) ) )  →  ¬  𝑅  ≤  𝑋 ) | 
						
							| 16 |  | simp1l | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑋  ∈  𝐵 )  ∧  ( 𝑃  ∈  𝐴  ∧  𝑄  ∈  𝐴  ∧  𝑅  ∈  𝐴 )  ∧  ( ( 𝑅  ≠  𝑃  ∧  𝑅  ≤  ( 𝑃  ∨  𝑄 ) )  ∧  ( 𝑃  ≤  𝑋  ∧  ¬  𝑄  ≤  𝑋 ) ) )  →  𝐾  ∈  HL ) | 
						
							| 17 |  | hlatl | ⊢ ( 𝐾  ∈  HL  →  𝐾  ∈  AtLat ) | 
						
							| 18 | 16 17 | syl | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑋  ∈  𝐵 )  ∧  ( 𝑃  ∈  𝐴  ∧  𝑄  ∈  𝐴  ∧  𝑅  ∈  𝐴 )  ∧  ( ( 𝑅  ≠  𝑃  ∧  𝑅  ≤  ( 𝑃  ∨  𝑄 ) )  ∧  ( 𝑃  ≤  𝑋  ∧  ¬  𝑄  ≤  𝑋 ) ) )  →  𝐾  ∈  AtLat ) | 
						
							| 19 |  | simp23 | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑋  ∈  𝐵 )  ∧  ( 𝑃  ∈  𝐴  ∧  𝑄  ∈  𝐴  ∧  𝑅  ∈  𝐴 )  ∧  ( ( 𝑅  ≠  𝑃  ∧  𝑅  ≤  ( 𝑃  ∨  𝑄 ) )  ∧  ( 𝑃  ≤  𝑋  ∧  ¬  𝑄  ≤  𝑋 ) ) )  →  𝑅  ∈  𝐴 ) | 
						
							| 20 |  | simp1r | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑋  ∈  𝐵 )  ∧  ( 𝑃  ∈  𝐴  ∧  𝑄  ∈  𝐴  ∧  𝑅  ∈  𝐴 )  ∧  ( ( 𝑅  ≠  𝑃  ∧  𝑅  ≤  ( 𝑃  ∨  𝑄 ) )  ∧  ( 𝑃  ≤  𝑋  ∧  ¬  𝑄  ≤  𝑋 ) ) )  →  𝑋  ∈  𝐵 ) | 
						
							| 21 | 1 2 4 5 6 | atnle | ⊢ ( ( 𝐾  ∈  AtLat  ∧  𝑅  ∈  𝐴  ∧  𝑋  ∈  𝐵 )  →  ( ¬  𝑅  ≤  𝑋  ↔  ( 𝑅  ∧  𝑋 )  =   0  ) ) | 
						
							| 22 | 18 19 20 21 | syl3anc | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑋  ∈  𝐵 )  ∧  ( 𝑃  ∈  𝐴  ∧  𝑄  ∈  𝐴  ∧  𝑅  ∈  𝐴 )  ∧  ( ( 𝑅  ≠  𝑃  ∧  𝑅  ≤  ( 𝑃  ∨  𝑄 ) )  ∧  ( 𝑃  ≤  𝑋  ∧  ¬  𝑄  ≤  𝑋 ) ) )  →  ( ¬  𝑅  ≤  𝑋  ↔  ( 𝑅  ∧  𝑋 )  =   0  ) ) | 
						
							| 23 | 15 22 | mpbid | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑋  ∈  𝐵 )  ∧  ( 𝑃  ∈  𝐴  ∧  𝑄  ∈  𝐴  ∧  𝑅  ∈  𝐴 )  ∧  ( ( 𝑅  ≠  𝑃  ∧  𝑅  ≤  ( 𝑃  ∨  𝑄 ) )  ∧  ( 𝑃  ≤  𝑋  ∧  ¬  𝑄  ≤  𝑋 ) ) )  →  ( 𝑅  ∧  𝑋 )  =   0  ) |