| 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 | 
							
								
							 | 
							dalem23.m | 
							 |-  ./\ = ( meet ` K )  | 
						
						
							| 7 | 
							
								
							 | 
							dalem23.o | 
							 |-  O = ( LPlanes ` K )  | 
						
						
							| 8 | 
							
								
							 | 
							dalem23.y | 
							 |-  Y = ( ( P .\/ Q ) .\/ R )  | 
						
						
							| 9 | 
							
								
							 | 
							dalem23.z | 
							 |-  Z = ( ( S .\/ T ) .\/ U )  | 
						
						
							| 10 | 
							
								
							 | 
							dalem23.g | 
							 |-  G = ( ( c .\/ P ) ./\ ( d .\/ S ) )  | 
						
						
							| 11 | 
							
								1
							 | 
							dalemkehl | 
							 |-  ( ph -> K e. HL )  | 
						
						
							| 12 | 
							
								11
							 | 
							adantr | 
							 |-  ( ( ph /\ ps ) -> K e. HL )  | 
						
						
							| 13 | 
							
								5
							 | 
							dalemccea | 
							 |-  ( ps -> c e. A )  | 
						
						
							| 14 | 
							
								13
							 | 
							adantl | 
							 |-  ( ( ph /\ ps ) -> c e. A )  | 
						
						
							| 15 | 
							
								1
							 | 
							dalempea | 
							 |-  ( ph -> P e. A )  | 
						
						
							| 16 | 
							
								15
							 | 
							adantr | 
							 |-  ( ( ph /\ ps ) -> P e. A )  | 
						
						
							| 17 | 
							
								5
							 | 
							dalemddea | 
							 |-  ( ps -> d e. A )  | 
						
						
							| 18 | 
							
								17
							 | 
							adantl | 
							 |-  ( ( ph /\ ps ) -> d e. A )  | 
						
						
							| 19 | 
							
								1
							 | 
							dalemsea | 
							 |-  ( ph -> S e. A )  | 
						
						
							| 20 | 
							
								19
							 | 
							adantr | 
							 |-  ( ( ph /\ ps ) -> S e. A )  | 
						
						
							| 21 | 
							
								3 4
							 | 
							hlatj4 | 
							 |-  ( ( K e. HL /\ ( c e. A /\ P e. A ) /\ ( d e. A /\ S e. A ) ) -> ( ( c .\/ P ) .\/ ( d .\/ S ) ) = ( ( c .\/ d ) .\/ ( P .\/ S ) ) )  | 
						
						
							| 22 | 
							
								12 14 16 18 20 21
							 | 
							syl122anc | 
							 |-  ( ( ph /\ ps ) -> ( ( c .\/ P ) .\/ ( d .\/ S ) ) = ( ( c .\/ d ) .\/ ( P .\/ S ) ) )  | 
						
						
							| 23 | 
							
								22
							 | 
							3adant2 | 
							 |-  ( ( ph /\ Y = Z /\ ps ) -> ( ( c .\/ P ) .\/ ( d .\/ S ) ) = ( ( c .\/ d ) .\/ ( P .\/ S ) ) )  | 
						
						
							| 24 | 
							
								1 2 3 4 5 7 8 9
							 | 
							dalem22 | 
							 |-  ( ( ph /\ Y = Z /\ ps ) -> ( ( c .\/ d ) .\/ ( P .\/ S ) ) e. O )  | 
						
						
							| 25 | 
							
								23 24
							 | 
							eqeltrd | 
							 |-  ( ( ph /\ Y = Z /\ ps ) -> ( ( c .\/ P ) .\/ ( d .\/ S ) ) e. O )  | 
						
						
							| 26 | 
							
								11
							 | 
							3ad2ant1 | 
							 |-  ( ( ph /\ Y = Z /\ ps ) -> K e. HL )  | 
						
						
							| 27 | 
							
								1 2 3 4 7 8
							 | 
							dalemply | 
							 |-  ( ph -> P .<_ Y )  | 
						
						
							| 28 | 
							
								5
							 | 
							dalem-ccly | 
							 |-  ( ps -> -. c .<_ Y )  | 
						
						
							| 29 | 
							
								
							 | 
							nbrne2 | 
							 |-  ( ( P .<_ Y /\ -. c .<_ Y ) -> P =/= c )  | 
						
						
							| 30 | 
							
								27 28 29
							 | 
							syl2an | 
							 |-  ( ( ph /\ ps ) -> P =/= c )  | 
						
						
							| 31 | 
							
								30
							 | 
							necomd | 
							 |-  ( ( ph /\ ps ) -> c =/= P )  | 
						
						
							| 32 | 
							
								
							 | 
							eqid | 
							 |-  ( LLines ` K ) = ( LLines ` K )  | 
						
						
							| 33 | 
							
								3 4 32
							 | 
							llni2 | 
							 |-  ( ( ( K e. HL /\ c e. A /\ P e. A ) /\ c =/= P ) -> ( c .\/ P ) e. ( LLines ` K ) )  | 
						
						
							| 34 | 
							
								12 14 16 31 33
							 | 
							syl31anc | 
							 |-  ( ( ph /\ ps ) -> ( c .\/ P ) e. ( LLines ` K ) )  | 
						
						
							| 35 | 
							
								34
							 | 
							3adant2 | 
							 |-  ( ( ph /\ Y = Z /\ ps ) -> ( c .\/ P ) e. ( LLines ` K ) )  | 
						
						
							| 36 | 
							
								17
							 | 
							3ad2ant3 | 
							 |-  ( ( ph /\ Y = Z /\ ps ) -> d e. A )  | 
						
						
							| 37 | 
							
								19
							 | 
							3ad2ant1 | 
							 |-  ( ( ph /\ Y = Z /\ ps ) -> S e. A )  | 
						
						
							| 38 | 
							
								1 2 3 4 9
							 | 
							dalemsly | 
							 |-  ( ( ph /\ Y = Z ) -> S .<_ Y )  | 
						
						
							| 39 | 
							
								38
							 | 
							3adant3 | 
							 |-  ( ( ph /\ Y = Z /\ ps ) -> S .<_ Y )  | 
						
						
							| 40 | 
							
								5
							 | 
							dalem-ddly | 
							 |-  ( ps -> -. d .<_ Y )  | 
						
						
							| 41 | 
							
								40
							 | 
							3ad2ant3 | 
							 |-  ( ( ph /\ Y = Z /\ ps ) -> -. d .<_ Y )  | 
						
						
							| 42 | 
							
								
							 | 
							nbrne2 | 
							 |-  ( ( S .<_ Y /\ -. d .<_ Y ) -> S =/= d )  | 
						
						
							| 43 | 
							
								39 41 42
							 | 
							syl2anc | 
							 |-  ( ( ph /\ Y = Z /\ ps ) -> S =/= d )  | 
						
						
							| 44 | 
							
								43
							 | 
							necomd | 
							 |-  ( ( ph /\ Y = Z /\ ps ) -> d =/= S )  | 
						
						
							| 45 | 
							
								3 4 32
							 | 
							llni2 | 
							 |-  ( ( ( K e. HL /\ d e. A /\ S e. A ) /\ d =/= S ) -> ( d .\/ S ) e. ( LLines ` K ) )  | 
						
						
							| 46 | 
							
								26 36 37 44 45
							 | 
							syl31anc | 
							 |-  ( ( ph /\ Y = Z /\ ps ) -> ( d .\/ S ) e. ( LLines ` K ) )  | 
						
						
							| 47 | 
							
								3 6 4 32 7
							 | 
							2llnmj | 
							 |-  ( ( K e. HL /\ ( c .\/ P ) e. ( LLines ` K ) /\ ( d .\/ S ) e. ( LLines ` K ) ) -> ( ( ( c .\/ P ) ./\ ( d .\/ S ) ) e. A <-> ( ( c .\/ P ) .\/ ( d .\/ S ) ) e. O ) )  | 
						
						
							| 48 | 
							
								26 35 46 47
							 | 
							syl3anc | 
							 |-  ( ( ph /\ Y = Z /\ ps ) -> ( ( ( c .\/ P ) ./\ ( d .\/ S ) ) e. A <-> ( ( c .\/ P ) .\/ ( d .\/ S ) ) e. O ) )  | 
						
						
							| 49 | 
							
								25 48
							 | 
							mpbird | 
							 |-  ( ( ph /\ Y = Z /\ ps ) -> ( ( c .\/ P ) ./\ ( d .\/ S ) ) e. A )  | 
						
						
							| 50 | 
							
								10 49
							 | 
							eqeltrid | 
							 |-  ( ( ph /\ Y = Z /\ ps ) -> G e. A )  |