| Step | 
						Hyp | 
						Ref | 
						Expression | 
					
						
							| 1 | 
							
								
							 | 
							cdleme24.b | 
							⊢ 𝐵  =  ( Base ‘ 𝐾 )  | 
						
						
							| 2 | 
							
								
							 | 
							cdleme24.l | 
							⊢  ≤   =  ( le ‘ 𝐾 )  | 
						
						
							| 3 | 
							
								
							 | 
							cdleme24.j | 
							⊢  ∨   =  ( join ‘ 𝐾 )  | 
						
						
							| 4 | 
							
								
							 | 
							cdleme24.m | 
							⊢  ∧   =  ( meet ‘ 𝐾 )  | 
						
						
							| 5 | 
							
								
							 | 
							cdleme24.a | 
							⊢ 𝐴  =  ( Atoms ‘ 𝐾 )  | 
						
						
							| 6 | 
							
								
							 | 
							cdleme24.h | 
							⊢ 𝐻  =  ( LHyp ‘ 𝐾 )  | 
						
						
							| 7 | 
							
								
							 | 
							cdleme24.u | 
							⊢ 𝑈  =  ( ( 𝑃  ∨  𝑄 )  ∧  𝑊 )  | 
						
						
							| 8 | 
							
								
							 | 
							cdleme24.f | 
							⊢ 𝐹  =  ( ( 𝑠  ∨  𝑈 )  ∧  ( 𝑄  ∨  ( ( 𝑃  ∨  𝑠 )  ∧  𝑊 ) ) )  | 
						
						
							| 9 | 
							
								
							 | 
							cdleme24.n | 
							⊢ 𝑁  =  ( ( 𝑃  ∨  𝑄 )  ∧  ( 𝐹  ∨  ( ( 𝑅  ∨  𝑠 )  ∧  𝑊 ) ) )  | 
						
						
							| 10 | 
							
								
							 | 
							cdleme25cl.i | 
							⊢ 𝐼  =  ( ℩ 𝑢  ∈  𝐵 ∀ 𝑠  ∈  𝐴 ( ( ¬  𝑠  ≤  𝑊  ∧  ¬  𝑠  ≤  ( 𝑃  ∨  𝑄 ) )  →  𝑢  =  𝑁 ) )  | 
						
						
							| 11 | 
							
								1 2 3 4 5 6 7 8 9
							 | 
							cdleme25c | 
							⊢ ( ( ( ( 𝐾  ∈  HL  ∧  𝑊  ∈  𝐻 )  ∧  ( 𝑃  ∈  𝐴  ∧  ¬  𝑃  ≤  𝑊 )  ∧  ( 𝑄  ∈  𝐴  ∧  ¬  𝑄  ≤  𝑊 ) )  ∧  ( 𝑅  ∈  𝐴  ∧  ¬  𝑅  ≤  𝑊 )  ∧  ( 𝑃  ≠  𝑄  ∧  𝑅  ≤  ( 𝑃  ∨  𝑄 ) ) )  →  ∃! 𝑢  ∈  𝐵 ∀ 𝑠  ∈  𝐴 ( ( ¬  𝑠  ≤  𝑊  ∧  ¬  𝑠  ≤  ( 𝑃  ∨  𝑄 ) )  →  𝑢  =  𝑁 ) )  | 
						
						
							| 12 | 
							
								
							 | 
							riotacl | 
							⊢ ( ∃! 𝑢  ∈  𝐵 ∀ 𝑠  ∈  𝐴 ( ( ¬  𝑠  ≤  𝑊  ∧  ¬  𝑠  ≤  ( 𝑃  ∨  𝑄 ) )  →  𝑢  =  𝑁 )  →  ( ℩ 𝑢  ∈  𝐵 ∀ 𝑠  ∈  𝐴 ( ( ¬  𝑠  ≤  𝑊  ∧  ¬  𝑠  ≤  ( 𝑃  ∨  𝑄 ) )  →  𝑢  =  𝑁 ) )  ∈  𝐵 )  | 
						
						
							| 13 | 
							
								11 12
							 | 
							syl | 
							⊢ ( ( ( ( 𝐾  ∈  HL  ∧  𝑊  ∈  𝐻 )  ∧  ( 𝑃  ∈  𝐴  ∧  ¬  𝑃  ≤  𝑊 )  ∧  ( 𝑄  ∈  𝐴  ∧  ¬  𝑄  ≤  𝑊 ) )  ∧  ( 𝑅  ∈  𝐴  ∧  ¬  𝑅  ≤  𝑊 )  ∧  ( 𝑃  ≠  𝑄  ∧  𝑅  ≤  ( 𝑃  ∨  𝑄 ) ) )  →  ( ℩ 𝑢  ∈  𝐵 ∀ 𝑠  ∈  𝐴 ( ( ¬  𝑠  ≤  𝑊  ∧  ¬  𝑠  ≤  ( 𝑃  ∨  𝑄 ) )  →  𝑢  =  𝑁 ) )  ∈  𝐵 )  | 
						
						
							| 14 | 
							
								10 13
							 | 
							eqeltrid | 
							⊢ ( ( ( ( 𝐾  ∈  HL  ∧  𝑊  ∈  𝐻 )  ∧  ( 𝑃  ∈  𝐴  ∧  ¬  𝑃  ≤  𝑊 )  ∧  ( 𝑄  ∈  𝐴  ∧  ¬  𝑄  ≤  𝑊 ) )  ∧  ( 𝑅  ∈  𝐴  ∧  ¬  𝑅  ≤  𝑊 )  ∧  ( 𝑃  ≠  𝑄  ∧  𝑅  ≤  ( 𝑃  ∨  𝑄 ) ) )  →  𝐼  ∈  𝐵 )  |