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