| Step | 
						Hyp | 
						Ref | 
						Expression | 
					
						
							| 1 | 
							
								
							 | 
							olj0.b | 
							⊢ 𝐵  =  ( Base ‘ 𝐾 )  | 
						
						
							| 2 | 
							
								
							 | 
							olj0.j | 
							⊢  ∨   =  ( join ‘ 𝐾 )  | 
						
						
							| 3 | 
							
								
							 | 
							olj0.z | 
							⊢  0   =  ( 0. ‘ 𝐾 )  | 
						
						
							| 4 | 
							
								
							 | 
							olop | 
							⊢ ( 𝐾  ∈  OL  →  𝐾  ∈  OP )  | 
						
						
							| 5 | 
							
								1 3
							 | 
							op0cl | 
							⊢ ( 𝐾  ∈  OP  →   0   ∈  𝐵 )  | 
						
						
							| 6 | 
							
								4 5
							 | 
							syl | 
							⊢ ( 𝐾  ∈  OL  →   0   ∈  𝐵 )  | 
						
						
							| 7 | 
							
								6
							 | 
							adantr | 
							⊢ ( ( 𝐾  ∈  OL  ∧  𝑋  ∈  𝐵 )  →   0   ∈  𝐵 )  | 
						
						
							| 8 | 
							
								
							 | 
							eqid | 
							⊢ ( le ‘ 𝐾 )  =  ( le ‘ 𝐾 )  | 
						
						
							| 9 | 
							
								
							 | 
							ollat | 
							⊢ ( 𝐾  ∈  OL  →  𝐾  ∈  Lat )  | 
						
						
							| 10 | 
							
								9
							 | 
							3ad2ant1 | 
							⊢ ( ( 𝐾  ∈  OL  ∧  𝑋  ∈  𝐵  ∧   0   ∈  𝐵 )  →  𝐾  ∈  Lat )  | 
						
						
							| 11 | 
							
								1 2
							 | 
							latjcl | 
							⊢ ( ( 𝐾  ∈  Lat  ∧  𝑋  ∈  𝐵  ∧   0   ∈  𝐵 )  →  ( 𝑋  ∨   0  )  ∈  𝐵 )  | 
						
						
							| 12 | 
							
								9 11
							 | 
							syl3an1 | 
							⊢ ( ( 𝐾  ∈  OL  ∧  𝑋  ∈  𝐵  ∧   0   ∈  𝐵 )  →  ( 𝑋  ∨   0  )  ∈  𝐵 )  | 
						
						
							| 13 | 
							
								
							 | 
							simp2 | 
							⊢ ( ( 𝐾  ∈  OL  ∧  𝑋  ∈  𝐵  ∧   0   ∈  𝐵 )  →  𝑋  ∈  𝐵 )  | 
						
						
							| 14 | 
							
								1 8
							 | 
							latref | 
							⊢ ( ( 𝐾  ∈  Lat  ∧  𝑋  ∈  𝐵 )  →  𝑋 ( le ‘ 𝐾 ) 𝑋 )  | 
						
						
							| 15 | 
							
								9 14
							 | 
							sylan | 
							⊢ ( ( 𝐾  ∈  OL  ∧  𝑋  ∈  𝐵 )  →  𝑋 ( le ‘ 𝐾 ) 𝑋 )  | 
						
						
							| 16 | 
							
								15
							 | 
							3adant3 | 
							⊢ ( ( 𝐾  ∈  OL  ∧  𝑋  ∈  𝐵  ∧   0   ∈  𝐵 )  →  𝑋 ( le ‘ 𝐾 ) 𝑋 )  | 
						
						
							| 17 | 
							
								1 8 3
							 | 
							op0le | 
							⊢ ( ( 𝐾  ∈  OP  ∧  𝑋  ∈  𝐵 )  →   0  ( le ‘ 𝐾 ) 𝑋 )  | 
						
						
							| 18 | 
							
								4 17
							 | 
							sylan | 
							⊢ ( ( 𝐾  ∈  OL  ∧  𝑋  ∈  𝐵 )  →   0  ( le ‘ 𝐾 ) 𝑋 )  | 
						
						
							| 19 | 
							
								18
							 | 
							3adant3 | 
							⊢ ( ( 𝐾  ∈  OL  ∧  𝑋  ∈  𝐵  ∧   0   ∈  𝐵 )  →   0  ( le ‘ 𝐾 ) 𝑋 )  | 
						
						
							| 20 | 
							
								
							 | 
							simp3 | 
							⊢ ( ( 𝐾  ∈  OL  ∧  𝑋  ∈  𝐵  ∧   0   ∈  𝐵 )  →   0   ∈  𝐵 )  | 
						
						
							| 21 | 
							
								1 8 2
							 | 
							latjle12 | 
							⊢ ( ( 𝐾  ∈  Lat  ∧  ( 𝑋  ∈  𝐵  ∧   0   ∈  𝐵  ∧  𝑋  ∈  𝐵 ) )  →  ( ( 𝑋 ( le ‘ 𝐾 ) 𝑋  ∧   0  ( le ‘ 𝐾 ) 𝑋 )  ↔  ( 𝑋  ∨   0  ) ( le ‘ 𝐾 ) 𝑋 ) )  | 
						
						
							| 22 | 
							
								10 13 20 13 21
							 | 
							syl13anc | 
							⊢ ( ( 𝐾  ∈  OL  ∧  𝑋  ∈  𝐵  ∧   0   ∈  𝐵 )  →  ( ( 𝑋 ( le ‘ 𝐾 ) 𝑋  ∧   0  ( le ‘ 𝐾 ) 𝑋 )  ↔  ( 𝑋  ∨   0  ) ( le ‘ 𝐾 ) 𝑋 ) )  | 
						
						
							| 23 | 
							
								16 19 22
							 | 
							mpbi2and | 
							⊢ ( ( 𝐾  ∈  OL  ∧  𝑋  ∈  𝐵  ∧   0   ∈  𝐵 )  →  ( 𝑋  ∨   0  ) ( le ‘ 𝐾 ) 𝑋 )  | 
						
						
							| 24 | 
							
								1 8 2
							 | 
							latlej1 | 
							⊢ ( ( 𝐾  ∈  Lat  ∧  𝑋  ∈  𝐵  ∧   0   ∈  𝐵 )  →  𝑋 ( le ‘ 𝐾 ) ( 𝑋  ∨   0  ) )  | 
						
						
							| 25 | 
							
								9 24
							 | 
							syl3an1 | 
							⊢ ( ( 𝐾  ∈  OL  ∧  𝑋  ∈  𝐵  ∧   0   ∈  𝐵 )  →  𝑋 ( le ‘ 𝐾 ) ( 𝑋  ∨   0  ) )  | 
						
						
							| 26 | 
							
								1 8 10 12 13 23 25
							 | 
							latasymd | 
							⊢ ( ( 𝐾  ∈  OL  ∧  𝑋  ∈  𝐵  ∧   0   ∈  𝐵 )  →  ( 𝑋  ∨   0  )  =  𝑋 )  | 
						
						
							| 27 | 
							
								7 26
							 | 
							mpd3an3 | 
							⊢ ( ( 𝐾  ∈  OL  ∧  𝑋  ∈  𝐵 )  →  ( 𝑋  ∨   0  )  =  𝑋 )  |