| Step | 
						Hyp | 
						Ref | 
						Expression | 
					
						
							| 1 | 
							
								
							 | 
							dalema.ph | 
							 |-  ( ph <-> ( ( ( K e. HL /\ C e. ( Base ` K ) ) /\ ( P e. A /\ Q e. A /\ R e. A ) /\ ( S e. A /\ T e. A /\ U e. A ) ) /\ ( Y e. O /\ Z e. 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 | 
							
								
							 | 
							dalemc.l | 
							 |-  .<_ = ( le ` K )  | 
						
						
							| 3 | 
							
								
							 | 
							dalemc.j | 
							 |-  .\/ = ( join ` K )  | 
						
						
							| 4 | 
							
								
							 | 
							dalemc.a | 
							 |-  A = ( Atoms ` K )  | 
						
						
							| 5 | 
							
								
							 | 
							dalem6.o | 
							 |-  O = ( LPlanes ` K )  | 
						
						
							| 6 | 
							
								
							 | 
							dalem6.y | 
							 |-  Y = ( ( P .\/ Q ) .\/ R )  | 
						
						
							| 7 | 
							
								
							 | 
							dalem6.z | 
							 |-  Z = ( ( S .\/ T ) .\/ U )  | 
						
						
							| 8 | 
							
								
							 | 
							dalem6.w | 
							 |-  W = ( Y .\/ C )  | 
						
						
							| 9 | 
							
								1 2 3 4 6 7
							 | 
							dalemrot | 
							 |-  ( ph -> ( ( ( K e. HL /\ C e. ( Base ` K ) ) /\ ( Q e. A /\ R e. A /\ P e. A ) /\ ( T e. A /\ U e. A /\ S e. A ) ) /\ ( ( ( Q .\/ R ) .\/ P ) e. O /\ ( ( T .\/ U ) .\/ S ) e. O ) /\ ( ( -. C .<_ ( Q .\/ R ) /\ -. C .<_ ( R .\/ P ) /\ -. C .<_ ( P .\/ Q ) ) /\ ( -. C .<_ ( T .\/ U ) /\ -. C .<_ ( U .\/ S ) /\ -. C .<_ ( S .\/ T ) ) /\ ( C .<_ ( Q .\/ T ) /\ C .<_ ( R .\/ U ) /\ C .<_ ( P .\/ S ) ) ) ) )  | 
						
						
							| 10 | 
							
								
							 | 
							biid | 
							 |-  ( ( ( ( K e. HL /\ C e. ( Base ` K ) ) /\ ( Q e. A /\ R e. A /\ P e. A ) /\ ( T e. A /\ U e. A /\ S e. A ) ) /\ ( ( ( Q .\/ R ) .\/ P ) e. O /\ ( ( T .\/ U ) .\/ S ) e. O ) /\ ( ( -. C .<_ ( Q .\/ R ) /\ -. C .<_ ( R .\/ P ) /\ -. C .<_ ( P .\/ Q ) ) /\ ( -. C .<_ ( T .\/ U ) /\ -. C .<_ ( U .\/ S ) /\ -. C .<_ ( S .\/ T ) ) /\ ( C .<_ ( Q .\/ T ) /\ C .<_ ( R .\/ U ) /\ C .<_ ( P .\/ S ) ) ) ) <-> ( ( ( K e. HL /\ C e. ( Base ` K ) ) /\ ( Q e. A /\ R e. A /\ P e. A ) /\ ( T e. A /\ U e. A /\ S e. A ) ) /\ ( ( ( Q .\/ R ) .\/ P ) e. O /\ ( ( T .\/ U ) .\/ S ) e. O ) /\ ( ( -. C .<_ ( Q .\/ R ) /\ -. C .<_ ( R .\/ P ) /\ -. C .<_ ( P .\/ Q ) ) /\ ( -. C .<_ ( T .\/ U ) /\ -. C .<_ ( U .\/ S ) /\ -. C .<_ ( S .\/ T ) ) /\ ( C .<_ ( Q .\/ T ) /\ C .<_ ( R .\/ U ) /\ C .<_ ( P .\/ S ) ) ) ) )  | 
						
						
							| 11 | 
							
								
							 | 
							eqid | 
							 |-  ( ( Q .\/ R ) .\/ P ) = ( ( Q .\/ R ) .\/ P )  | 
						
						
							| 12 | 
							
								
							 | 
							eqid | 
							 |-  ( ( T .\/ U ) .\/ S ) = ( ( T .\/ U ) .\/ S )  | 
						
						
							| 13 | 
							
								
							 | 
							eqid | 
							 |-  ( ( ( Q .\/ R ) .\/ P ) .\/ C ) = ( ( ( Q .\/ R ) .\/ P ) .\/ C )  | 
						
						
							| 14 | 
							
								10 2 3 4 5 11 12 13
							 | 
							dalem6 | 
							 |-  ( ( ( ( K e. HL /\ C e. ( Base ` K ) ) /\ ( Q e. A /\ R e. A /\ P e. A ) /\ ( T e. A /\ U e. A /\ S e. A ) ) /\ ( ( ( Q .\/ R ) .\/ P ) e. O /\ ( ( T .\/ U ) .\/ S ) e. O ) /\ ( ( -. C .<_ ( Q .\/ R ) /\ -. C .<_ ( R .\/ P ) /\ -. C .<_ ( P .\/ Q ) ) /\ ( -. C .<_ ( T .\/ U ) /\ -. C .<_ ( U .\/ S ) /\ -. C .<_ ( S .\/ T ) ) /\ ( C .<_ ( Q .\/ T ) /\ C .<_ ( R .\/ U ) /\ C .<_ ( P .\/ S ) ) ) ) -> T .<_ ( ( ( Q .\/ R ) .\/ P ) .\/ C ) )  | 
						
						
							| 15 | 
							
								9 14
							 | 
							syl | 
							 |-  ( ph -> T .<_ ( ( ( Q .\/ R ) .\/ P ) .\/ C ) )  | 
						
						
							| 16 | 
							
								1 3 4
							 | 
							dalemqrprot | 
							 |-  ( ph -> ( ( Q .\/ R ) .\/ P ) = ( ( P .\/ Q ) .\/ R ) )  | 
						
						
							| 17 | 
							
								6 16
							 | 
							eqtr4id | 
							 |-  ( ph -> Y = ( ( Q .\/ R ) .\/ P ) )  | 
						
						
							| 18 | 
							
								17
							 | 
							oveq1d | 
							 |-  ( ph -> ( Y .\/ C ) = ( ( ( Q .\/ R ) .\/ P ) .\/ C ) )  | 
						
						
							| 19 | 
							
								8 18
							 | 
							eqtrid | 
							 |-  ( ph -> W = ( ( ( Q .\/ R ) .\/ P ) .\/ C ) )  | 
						
						
							| 20 | 
							
								15 19
							 | 
							breqtrrd | 
							 |-  ( ph -> T .<_ W )  |