| Step | 
						Hyp | 
						Ref | 
						Expression | 
					
						
							| 1 | 
							
								
							 | 
							cdleme32s.b | 
							⊢ 𝐵  =  ( Base ‘ 𝐾 )  | 
						
						
							| 2 | 
							
								
							 | 
							cdleme32s.l | 
							⊢  ≤   =  ( le ‘ 𝐾 )  | 
						
						
							| 3 | 
							
								
							 | 
							cdleme32s.j | 
							⊢  ∨   =  ( join ‘ 𝐾 )  | 
						
						
							| 4 | 
							
								
							 | 
							cdleme32s.m | 
							⊢  ∧   =  ( meet ‘ 𝐾 )  | 
						
						
							| 5 | 
							
								
							 | 
							cdleme32s.a | 
							⊢ 𝐴  =  ( Atoms ‘ 𝐾 )  | 
						
						
							| 6 | 
							
								
							 | 
							cdleme32s.h | 
							⊢ 𝐻  =  ( LHyp ‘ 𝐾 )  | 
						
						
							| 7 | 
							
								
							 | 
							cdleme32s.u | 
							⊢ 𝑈  =  ( ( 𝑃  ∨  𝑄 )  ∧  𝑊 )  | 
						
						
							| 8 | 
							
								
							 | 
							cdleme32s.d | 
							⊢ 𝐷  =  ( ( 𝑠  ∨  𝑈 )  ∧  ( 𝑄  ∨  ( ( 𝑃  ∨  𝑠 )  ∧  𝑊 ) ) )  | 
						
						
							| 9 | 
							
								
							 | 
							cdleme32s.n | 
							⊢ 𝑁  =  if ( 𝑠  ≤  ( 𝑃  ∨  𝑄 ) ,  𝐼 ,  𝐷 )  | 
						
						
							| 10 | 
							
								
							 | 
							eqid | 
							⊢ ( ( 𝑅  ∨  𝑈 )  ∧  ( 𝑄  ∨  ( ( 𝑃  ∨  𝑅 )  ∧  𝑊 ) ) )  =  ( ( 𝑅  ∨  𝑈 )  ∧  ( 𝑄  ∨  ( ( 𝑃  ∨  𝑅 )  ∧  𝑊 ) ) )  | 
						
						
							| 11 | 
							
								2 3 4 5 6 7 10
							 | 
							cdleme35fnpq | 
							⊢ ( ( ( ( 𝐾  ∈  HL  ∧  𝑊  ∈  𝐻 )  ∧  ( 𝑃  ∈  𝐴  ∧  ¬  𝑃  ≤  𝑊 )  ∧  ( 𝑄  ∈  𝐴  ∧  ¬  𝑄  ≤  𝑊 ) )  ∧  ( 𝑃  ≠  𝑄  ∧  ( 𝑅  ∈  𝐴  ∧  ¬  𝑅  ≤  𝑊 ) )  ∧  ¬  𝑅  ≤  ( 𝑃  ∨  𝑄 ) )  →  ¬  ( ( 𝑅  ∨  𝑈 )  ∧  ( 𝑄  ∨  ( ( 𝑃  ∨  𝑅 )  ∧  𝑊 ) ) )  ≤  ( 𝑃  ∨  𝑄 ) )  | 
						
						
							| 12 | 
							
								
							 | 
							simp2rl | 
							⊢ ( ( ( ( 𝐾  ∈  HL  ∧  𝑊  ∈  𝐻 )  ∧  ( 𝑃  ∈  𝐴  ∧  ¬  𝑃  ≤  𝑊 )  ∧  ( 𝑄  ∈  𝐴  ∧  ¬  𝑄  ≤  𝑊 ) )  ∧  ( 𝑃  ≠  𝑄  ∧  ( 𝑅  ∈  𝐴  ∧  ¬  𝑅  ≤  𝑊 ) )  ∧  ¬  𝑅  ≤  ( 𝑃  ∨  𝑄 ) )  →  𝑅  ∈  𝐴 )  | 
						
						
							| 13 | 
							
								
							 | 
							simp3 | 
							⊢ ( ( ( ( 𝐾  ∈  HL  ∧  𝑊  ∈  𝐻 )  ∧  ( 𝑃  ∈  𝐴  ∧  ¬  𝑃  ≤  𝑊 )  ∧  ( 𝑄  ∈  𝐴  ∧  ¬  𝑄  ≤  𝑊 ) )  ∧  ( 𝑃  ≠  𝑄  ∧  ( 𝑅  ∈  𝐴  ∧  ¬  𝑅  ≤  𝑊 ) )  ∧  ¬  𝑅  ≤  ( 𝑃  ∨  𝑄 ) )  →  ¬  𝑅  ≤  ( 𝑃  ∨  𝑄 ) )  | 
						
						
							| 14 | 
							
								8 9 10
							 | 
							cdleme31sn2 | 
							⊢ ( ( 𝑅  ∈  𝐴  ∧  ¬  𝑅  ≤  ( 𝑃  ∨  𝑄 ) )  →  ⦋ 𝑅  /  𝑠 ⦌ 𝑁  =  ( ( 𝑅  ∨  𝑈 )  ∧  ( 𝑄  ∨  ( ( 𝑃  ∨  𝑅 )  ∧  𝑊 ) ) ) )  | 
						
						
							| 15 | 
							
								12 13 14
							 | 
							syl2anc | 
							⊢ ( ( ( ( 𝐾  ∈  HL  ∧  𝑊  ∈  𝐻 )  ∧  ( 𝑃  ∈  𝐴  ∧  ¬  𝑃  ≤  𝑊 )  ∧  ( 𝑄  ∈  𝐴  ∧  ¬  𝑄  ≤  𝑊 ) )  ∧  ( 𝑃  ≠  𝑄  ∧  ( 𝑅  ∈  𝐴  ∧  ¬  𝑅  ≤  𝑊 ) )  ∧  ¬  𝑅  ≤  ( 𝑃  ∨  𝑄 ) )  →  ⦋ 𝑅  /  𝑠 ⦌ 𝑁  =  ( ( 𝑅  ∨  𝑈 )  ∧  ( 𝑄  ∨  ( ( 𝑃  ∨  𝑅 )  ∧  𝑊 ) ) ) )  | 
						
						
							| 16 | 
							
								15
							 | 
							breq1d | 
							⊢ ( ( ( ( 𝐾  ∈  HL  ∧  𝑊  ∈  𝐻 )  ∧  ( 𝑃  ∈  𝐴  ∧  ¬  𝑃  ≤  𝑊 )  ∧  ( 𝑄  ∈  𝐴  ∧  ¬  𝑄  ≤  𝑊 ) )  ∧  ( 𝑃  ≠  𝑄  ∧  ( 𝑅  ∈  𝐴  ∧  ¬  𝑅  ≤  𝑊 ) )  ∧  ¬  𝑅  ≤  ( 𝑃  ∨  𝑄 ) )  →  ( ⦋ 𝑅  /  𝑠 ⦌ 𝑁  ≤  ( 𝑃  ∨  𝑄 )  ↔  ( ( 𝑅  ∨  𝑈 )  ∧  ( 𝑄  ∨  ( ( 𝑃  ∨  𝑅 )  ∧  𝑊 ) ) )  ≤  ( 𝑃  ∨  𝑄 ) ) )  | 
						
						
							| 17 | 
							
								11 16
							 | 
							mtbird | 
							⊢ ( ( ( ( 𝐾  ∈  HL  ∧  𝑊  ∈  𝐻 )  ∧  ( 𝑃  ∈  𝐴  ∧  ¬  𝑃  ≤  𝑊 )  ∧  ( 𝑄  ∈  𝐴  ∧  ¬  𝑄  ≤  𝑊 ) )  ∧  ( 𝑃  ≠  𝑄  ∧  ( 𝑅  ∈  𝐴  ∧  ¬  𝑅  ≤  𝑊 ) )  ∧  ¬  𝑅  ≤  ( 𝑃  ∨  𝑄 ) )  →  ¬  ⦋ 𝑅  /  𝑠 ⦌ 𝑁  ≤  ( 𝑃  ∨  𝑄 ) )  |