| Step | 
						Hyp | 
						Ref | 
						Expression | 
					
						
							| 1 | 
							
								
							 | 
							dalem.ph | 
							⊢ ( 𝜑  ↔  ( ( ( 𝐾  ∈  HL  ∧  𝐶  ∈  ( Base ‘ 𝐾 ) )  ∧  ( 𝑃  ∈  𝐴  ∧  𝑄  ∈  𝐴  ∧  𝑅  ∈  𝐴 )  ∧  ( 𝑆  ∈  𝐴  ∧  𝑇  ∈  𝐴  ∧  𝑈  ∈  𝐴 ) )  ∧  ( 𝑌  ∈  𝑂  ∧  𝑍  ∈  𝑂 )  ∧  ( ( ¬  𝐶  ≤  ( 𝑃  ∨  𝑄 )  ∧  ¬  𝐶  ≤  ( 𝑄  ∨  𝑅 )  ∧  ¬  𝐶  ≤  ( 𝑅  ∨  𝑃 ) )  ∧  ( ¬  𝐶  ≤  ( 𝑆  ∨  𝑇 )  ∧  ¬  𝐶  ≤  ( 𝑇  ∨  𝑈 )  ∧  ¬  𝐶  ≤  ( 𝑈  ∨  𝑆 ) )  ∧  ( 𝐶  ≤  ( 𝑃  ∨  𝑆 )  ∧  𝐶  ≤  ( 𝑄  ∨  𝑇 )  ∧  𝐶  ≤  ( 𝑅  ∨  𝑈 ) ) ) ) )  | 
						
						
							| 2 | 
							
								
							 | 
							dalem.l | 
							⊢  ≤   =  ( le ‘ 𝐾 )  | 
						
						
							| 3 | 
							
								
							 | 
							dalem.j | 
							⊢  ∨   =  ( join ‘ 𝐾 )  | 
						
						
							| 4 | 
							
								
							 | 
							dalem.a | 
							⊢ 𝐴  =  ( Atoms ‘ 𝐾 )  | 
						
						
							| 5 | 
							
								
							 | 
							dalem.ps | 
							⊢ ( 𝜓  ↔  ( ( 𝑐  ∈  𝐴  ∧  𝑑  ∈  𝐴 )  ∧  ¬  𝑐  ≤  𝑌  ∧  ( 𝑑  ≠  𝑐  ∧  ¬  𝑑  ≤  𝑌  ∧  𝐶  ≤  ( 𝑐  ∨  𝑑 ) ) ) )  | 
						
						
							| 6 | 
							
								5
							 | 
							dalemddea | 
							⊢ ( 𝜓  →  𝑑  ∈  𝐴 )  | 
						
						
							| 7 | 
							
								5
							 | 
							dalemccea | 
							⊢ ( 𝜓  →  𝑐  ∈  𝐴 )  | 
						
						
							| 8 | 
							
								6 7
							 | 
							jca | 
							⊢ ( 𝜓  →  ( 𝑑  ∈  𝐴  ∧  𝑐  ∈  𝐴 ) )  | 
						
						
							| 9 | 
							
								8
							 | 
							3ad2ant3 | 
							⊢ ( ( 𝜑  ∧  𝑌  =  𝑍  ∧  𝜓 )  →  ( 𝑑  ∈  𝐴  ∧  𝑐  ∈  𝐴 ) )  | 
						
						
							| 10 | 
							
								5
							 | 
							dalem-ddly | 
							⊢ ( 𝜓  →  ¬  𝑑  ≤  𝑌 )  | 
						
						
							| 11 | 
							
								10
							 | 
							3ad2ant3 | 
							⊢ ( ( 𝜑  ∧  𝑌  =  𝑍  ∧  𝜓 )  →  ¬  𝑑  ≤  𝑌 )  | 
						
						
							| 12 | 
							
								
							 | 
							simp2 | 
							⊢ ( ( 𝜑  ∧  𝑌  =  𝑍  ∧  𝜓 )  →  𝑌  =  𝑍 )  | 
						
						
							| 13 | 
							
								12
							 | 
							breq2d | 
							⊢ ( ( 𝜑  ∧  𝑌  =  𝑍  ∧  𝜓 )  →  ( 𝑑  ≤  𝑌  ↔  𝑑  ≤  𝑍 ) )  | 
						
						
							| 14 | 
							
								11 13
							 | 
							mtbid | 
							⊢ ( ( 𝜑  ∧  𝑌  =  𝑍  ∧  𝜓 )  →  ¬  𝑑  ≤  𝑍 )  | 
						
						
							| 15 | 
							
								5
							 | 
							dalemccnedd | 
							⊢ ( 𝜓  →  𝑐  ≠  𝑑 )  | 
						
						
							| 16 | 
							
								15
							 | 
							3ad2ant3 | 
							⊢ ( ( 𝜑  ∧  𝑌  =  𝑍  ∧  𝜓 )  →  𝑐  ≠  𝑑 )  | 
						
						
							| 17 | 
							
								5
							 | 
							dalem-ccly | 
							⊢ ( 𝜓  →  ¬  𝑐  ≤  𝑌 )  | 
						
						
							| 18 | 
							
								17
							 | 
							3ad2ant3 | 
							⊢ ( ( 𝜑  ∧  𝑌  =  𝑍  ∧  𝜓 )  →  ¬  𝑐  ≤  𝑌 )  | 
						
						
							| 19 | 
							
								12
							 | 
							breq2d | 
							⊢ ( ( 𝜑  ∧  𝑌  =  𝑍  ∧  𝜓 )  →  ( 𝑐  ≤  𝑌  ↔  𝑐  ≤  𝑍 ) )  | 
						
						
							| 20 | 
							
								18 19
							 | 
							mtbid | 
							⊢ ( ( 𝜑  ∧  𝑌  =  𝑍  ∧  𝜓 )  →  ¬  𝑐  ≤  𝑍 )  | 
						
						
							| 21 | 
							
								5
							 | 
							dalemclccjdd | 
							⊢ ( 𝜓  →  𝐶  ≤  ( 𝑐  ∨  𝑑 ) )  | 
						
						
							| 22 | 
							
								21
							 | 
							3ad2ant3 | 
							⊢ ( ( 𝜑  ∧  𝑌  =  𝑍  ∧  𝜓 )  →  𝐶  ≤  ( 𝑐  ∨  𝑑 ) )  | 
						
						
							| 23 | 
							
								1
							 | 
							dalemkehl | 
							⊢ ( 𝜑  →  𝐾  ∈  HL )  | 
						
						
							| 24 | 
							
								23
							 | 
							3ad2ant1 | 
							⊢ ( ( 𝜑  ∧  𝑌  =  𝑍  ∧  𝜓 )  →  𝐾  ∈  HL )  | 
						
						
							| 25 | 
							
								7
							 | 
							3ad2ant3 | 
							⊢ ( ( 𝜑  ∧  𝑌  =  𝑍  ∧  𝜓 )  →  𝑐  ∈  𝐴 )  | 
						
						
							| 26 | 
							
								6
							 | 
							3ad2ant3 | 
							⊢ ( ( 𝜑  ∧  𝑌  =  𝑍  ∧  𝜓 )  →  𝑑  ∈  𝐴 )  | 
						
						
							| 27 | 
							
								3 4
							 | 
							hlatjcom | 
							⊢ ( ( 𝐾  ∈  HL  ∧  𝑐  ∈  𝐴  ∧  𝑑  ∈  𝐴 )  →  ( 𝑐  ∨  𝑑 )  =  ( 𝑑  ∨  𝑐 ) )  | 
						
						
							| 28 | 
							
								24 25 26 27
							 | 
							syl3anc | 
							⊢ ( ( 𝜑  ∧  𝑌  =  𝑍  ∧  𝜓 )  →  ( 𝑐  ∨  𝑑 )  =  ( 𝑑  ∨  𝑐 ) )  | 
						
						
							| 29 | 
							
								22 28
							 | 
							breqtrd | 
							⊢ ( ( 𝜑  ∧  𝑌  =  𝑍  ∧  𝜓 )  →  𝐶  ≤  ( 𝑑  ∨  𝑐 ) )  | 
						
						
							| 30 | 
							
								16 20 29
							 | 
							3jca | 
							⊢ ( ( 𝜑  ∧  𝑌  =  𝑍  ∧  𝜓 )  →  ( 𝑐  ≠  𝑑  ∧  ¬  𝑐  ≤  𝑍  ∧  𝐶  ≤  ( 𝑑  ∨  𝑐 ) ) )  | 
						
						
							| 31 | 
							
								9 14 30
							 | 
							3jca | 
							⊢ ( ( 𝜑  ∧  𝑌  =  𝑍  ∧  𝜓 )  →  ( ( 𝑑  ∈  𝐴  ∧  𝑐  ∈  𝐴 )  ∧  ¬  𝑑  ≤  𝑍  ∧  ( 𝑐  ≠  𝑑  ∧  ¬  𝑐  ≤  𝑍  ∧  𝐶  ≤  ( 𝑑  ∨  𝑐 ) ) ) )  |