| Step | 
						Hyp | 
						Ref | 
						Expression | 
					
						
							| 1 | 
							
								
							 | 
							dalem.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 | 
							
								
							 | 
							dalem.l | 
							 |-  .<_ = ( le ` K )  | 
						
						
							| 3 | 
							
								
							 | 
							dalem.j | 
							 |-  .\/ = ( join ` K )  | 
						
						
							| 4 | 
							
								
							 | 
							dalem.a | 
							 |-  A = ( Atoms ` K )  | 
						
						
							| 5 | 
							
								
							 | 
							dalem.ps | 
							 |-  ( ps <-> ( ( c e. A /\ d e. A ) /\ -. c .<_ Y /\ ( d =/= c /\ -. d .<_ Y /\ C .<_ ( c .\/ d ) ) ) )  | 
						
						
							| 6 | 
							
								
							 | 
							dalemrotps.y | 
							 |-  Y = ( ( P .\/ Q ) .\/ R )  | 
						
						
							| 7 | 
							
								5
							 | 
							dalemccea | 
							 |-  ( ps -> c e. A )  | 
						
						
							| 8 | 
							
								5
							 | 
							dalemddea | 
							 |-  ( ps -> d e. A )  | 
						
						
							| 9 | 
							
								7 8
							 | 
							jca | 
							 |-  ( ps -> ( c e. A /\ d e. A ) )  | 
						
						
							| 10 | 
							
								9
							 | 
							adantl | 
							 |-  ( ( ph /\ ps ) -> ( c e. A /\ d e. A ) )  | 
						
						
							| 11 | 
							
								5
							 | 
							dalem-ccly | 
							 |-  ( ps -> -. c .<_ Y )  | 
						
						
							| 12 | 
							
								11
							 | 
							adantl | 
							 |-  ( ( ph /\ ps ) -> -. c .<_ Y )  | 
						
						
							| 13 | 
							
								1 3 4
							 | 
							dalemqrprot | 
							 |-  ( ph -> ( ( Q .\/ R ) .\/ P ) = ( ( P .\/ Q ) .\/ R ) )  | 
						
						
							| 14 | 
							
								6 13
							 | 
							eqtr4id | 
							 |-  ( ph -> Y = ( ( Q .\/ R ) .\/ P ) )  | 
						
						
							| 15 | 
							
								14
							 | 
							breq2d | 
							 |-  ( ph -> ( c .<_ Y <-> c .<_ ( ( Q .\/ R ) .\/ P ) ) )  | 
						
						
							| 16 | 
							
								15
							 | 
							adantr | 
							 |-  ( ( ph /\ ps ) -> ( c .<_ Y <-> c .<_ ( ( Q .\/ R ) .\/ P ) ) )  | 
						
						
							| 17 | 
							
								12 16
							 | 
							mtbid | 
							 |-  ( ( ph /\ ps ) -> -. c .<_ ( ( Q .\/ R ) .\/ P ) )  | 
						
						
							| 18 | 
							
								5
							 | 
							dalemccnedd | 
							 |-  ( ps -> c =/= d )  | 
						
						
							| 19 | 
							
								18
							 | 
							necomd | 
							 |-  ( ps -> d =/= c )  | 
						
						
							| 20 | 
							
								19
							 | 
							adantl | 
							 |-  ( ( ph /\ ps ) -> d =/= c )  | 
						
						
							| 21 | 
							
								5
							 | 
							dalem-ddly | 
							 |-  ( ps -> -. d .<_ Y )  | 
						
						
							| 22 | 
							
								21
							 | 
							adantl | 
							 |-  ( ( ph /\ ps ) -> -. d .<_ Y )  | 
						
						
							| 23 | 
							
								14
							 | 
							breq2d | 
							 |-  ( ph -> ( d .<_ Y <-> d .<_ ( ( Q .\/ R ) .\/ P ) ) )  | 
						
						
							| 24 | 
							
								23
							 | 
							adantr | 
							 |-  ( ( ph /\ ps ) -> ( d .<_ Y <-> d .<_ ( ( Q .\/ R ) .\/ P ) ) )  | 
						
						
							| 25 | 
							
								22 24
							 | 
							mtbid | 
							 |-  ( ( ph /\ ps ) -> -. d .<_ ( ( Q .\/ R ) .\/ P ) )  | 
						
						
							| 26 | 
							
								5
							 | 
							dalemclccjdd | 
							 |-  ( ps -> C .<_ ( c .\/ d ) )  | 
						
						
							| 27 | 
							
								26
							 | 
							adantl | 
							 |-  ( ( ph /\ ps ) -> C .<_ ( c .\/ d ) )  | 
						
						
							| 28 | 
							
								20 25 27
							 | 
							3jca | 
							 |-  ( ( ph /\ ps ) -> ( d =/= c /\ -. d .<_ ( ( Q .\/ R ) .\/ P ) /\ C .<_ ( c .\/ d ) ) )  | 
						
						
							| 29 | 
							
								10 17 28
							 | 
							3jca | 
							 |-  ( ( ph /\ ps ) -> ( ( c e. A /\ d e. A ) /\ -. c .<_ ( ( Q .\/ R ) .\/ P ) /\ ( d =/= c /\ -. d .<_ ( ( Q .\/ R ) .\/ P ) /\ C .<_ ( c .\/ d ) ) ) )  |