Metamath Proof Explorer
		
		
		
		Description:  Part of proof of Lemma E in Crawley p. 113.  (Contributed by NM, 12-Jun-2012)
		
			
				
					 | 
					 | 
					Ref | 
					Expression | 
				
					
						 | 
						Hypotheses | 
						cdleme0.l | 
						⊢  ≤   =  ( le ‘ 𝐾 )  | 
					
					
						 | 
						 | 
						cdleme0.j | 
						⊢  ∨   =  ( join ‘ 𝐾 )  | 
					
					
						 | 
						 | 
						cdleme0.m | 
						⊢  ∧   =  ( meet ‘ 𝐾 )  | 
					
					
						 | 
						 | 
						cdleme0.a | 
						⊢ 𝐴  =  ( Atoms ‘ 𝐾 )  | 
					
					
						 | 
						 | 
						cdleme0.h | 
						⊢ 𝐻  =  ( LHyp ‘ 𝐾 )  | 
					
					
						 | 
						 | 
						cdleme0.u | 
						⊢ 𝑈  =  ( ( 𝑃  ∨  𝑄 )  ∧  𝑊 )  | 
					
				
					 | 
					Assertion | 
					cdleme0a | 
					⊢  ( ( ( 𝐾  ∈  HL  ∧  𝑊  ∈  𝐻 )  ∧  ( 𝑃  ∈  𝐴  ∧  ¬  𝑃  ≤  𝑊 )  ∧  ( 𝑄  ∈  𝐴  ∧  𝑃  ≠  𝑄 ) )  →  𝑈  ∈  𝐴 )  | 
				
			
		
		
			
				Proof
				
					
						| Step | 
						Hyp | 
						Ref | 
						Expression | 
					
						
							| 1 | 
							
								
							 | 
							cdleme0.l | 
							⊢  ≤   =  ( le ‘ 𝐾 )  | 
						
						
							| 2 | 
							
								
							 | 
							cdleme0.j | 
							⊢  ∨   =  ( join ‘ 𝐾 )  | 
						
						
							| 3 | 
							
								
							 | 
							cdleme0.m | 
							⊢  ∧   =  ( meet ‘ 𝐾 )  | 
						
						
							| 4 | 
							
								
							 | 
							cdleme0.a | 
							⊢ 𝐴  =  ( Atoms ‘ 𝐾 )  | 
						
						
							| 5 | 
							
								
							 | 
							cdleme0.h | 
							⊢ 𝐻  =  ( LHyp ‘ 𝐾 )  | 
						
						
							| 6 | 
							
								
							 | 
							cdleme0.u | 
							⊢ 𝑈  =  ( ( 𝑃  ∨  𝑄 )  ∧  𝑊 )  | 
						
						
							| 7 | 
							
								1 2 3 4 5 6
							 | 
							lhpat2 | 
							⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑊  ∈  𝐻 )  ∧  ( 𝑃  ∈  𝐴  ∧  ¬  𝑃  ≤  𝑊 )  ∧  ( 𝑄  ∈  𝐴  ∧  𝑃  ≠  𝑄 ) )  →  𝑈  ∈  𝐴 )  |