| 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 | 
							
								
							 | 
							simpll | 
							 |-  ( ( ( K e. HL /\ W e. H ) /\ ( P e. A /\ Q e. A ) ) -> K e. HL )  | 
						
						
							| 8 | 
							
								7
							 | 
							hllatd | 
							 |-  ( ( ( K e. HL /\ W e. H ) /\ ( P e. A /\ Q e. A ) ) -> K e. Lat )  | 
						
						
							| 9 | 
							
								
							 | 
							simprl | 
							 |-  ( ( ( K e. HL /\ W e. H ) /\ ( P e. A /\ Q e. A ) ) -> P e. A )  | 
						
						
							| 10 | 
							
								
							 | 
							simprr | 
							 |-  ( ( ( K e. HL /\ W e. H ) /\ ( P e. A /\ Q e. A ) ) -> Q e. A )  | 
						
						
							| 11 | 
							
								
							 | 
							eqid | 
							 |-  ( Base ` K ) = ( Base ` K )  | 
						
						
							| 12 | 
							
								11 2 4
							 | 
							hlatjcl | 
							 |-  ( ( K e. HL /\ P e. A /\ Q e. A ) -> ( P .\/ Q ) e. ( Base ` K ) )  | 
						
						
							| 13 | 
							
								7 9 10 12
							 | 
							syl3anc | 
							 |-  ( ( ( K e. HL /\ W e. H ) /\ ( P e. A /\ Q e. A ) ) -> ( P .\/ Q ) e. ( Base ` K ) )  | 
						
						
							| 14 | 
							
								11 5
							 | 
							lhpbase | 
							 |-  ( W e. H -> W e. ( Base ` K ) )  | 
						
						
							| 15 | 
							
								14
							 | 
							ad2antlr | 
							 |-  ( ( ( K e. HL /\ W e. H ) /\ ( P e. A /\ Q e. A ) ) -> W e. ( Base ` K ) )  | 
						
						
							| 16 | 
							
								11 1 3
							 | 
							latmle1 | 
							 |-  ( ( K e. Lat /\ ( P .\/ Q ) e. ( Base ` K ) /\ W e. ( Base ` K ) ) -> ( ( P .\/ Q ) ./\ W ) .<_ ( P .\/ Q ) )  | 
						
						
							| 17 | 
							
								8 13 15 16
							 | 
							syl3anc | 
							 |-  ( ( ( K e. HL /\ W e. H ) /\ ( P e. A /\ Q e. A ) ) -> ( ( P .\/ Q ) ./\ W ) .<_ ( P .\/ Q ) )  | 
						
						
							| 18 | 
							
								6 17
							 | 
							eqbrtrid | 
							 |-  ( ( ( K e. HL /\ W e. H ) /\ ( P e. A /\ Q e. A ) ) -> U .<_ ( P .\/ Q ) )  |