| 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 | 
							
								
							 | 
							dalem57.m | 
							 |-  ./\ = ( meet ` K )  | 
						
						
							| 7 | 
							
								
							 | 
							dalem57.o | 
							 |-  O = ( LPlanes ` K )  | 
						
						
							| 8 | 
							
								
							 | 
							dalem57.y | 
							 |-  Y = ( ( P .\/ Q ) .\/ R )  | 
						
						
							| 9 | 
							
								
							 | 
							dalem57.z | 
							 |-  Z = ( ( S .\/ T ) .\/ U )  | 
						
						
							| 10 | 
							
								
							 | 
							dalem57.d | 
							 |-  D = ( ( P .\/ Q ) ./\ ( S .\/ T ) )  | 
						
						
							| 11 | 
							
								
							 | 
							dalem57.g | 
							 |-  G = ( ( c .\/ P ) ./\ ( d .\/ S ) )  | 
						
						
							| 12 | 
							
								
							 | 
							dalem57.h | 
							 |-  H = ( ( c .\/ Q ) ./\ ( d .\/ T ) )  | 
						
						
							| 13 | 
							
								
							 | 
							dalem57.i | 
							 |-  I = ( ( c .\/ R ) ./\ ( d .\/ U ) )  | 
						
						
							| 14 | 
							
								
							 | 
							dalem57.b1 | 
							 |-  B = ( ( ( G .\/ H ) .\/ I ) ./\ Y )  | 
						
						
							| 15 | 
							
								1 2 3 4 5 6 7 8 9 11 12 13 14
							 | 
							dalem55 | 
							 |-  ( ( ph /\ Y = Z /\ ps ) -> ( ( G .\/ H ) ./\ ( P .\/ Q ) ) = ( ( G .\/ H ) ./\ B ) )  | 
						
						
							| 16 | 
							
								1
							 | 
							dalemkelat | 
							 |-  ( ph -> K e. Lat )  | 
						
						
							| 17 | 
							
								16
							 | 
							3ad2ant1 | 
							 |-  ( ( ph /\ Y = Z /\ ps ) -> K e. Lat )  | 
						
						
							| 18 | 
							
								1
							 | 
							dalemkehl | 
							 |-  ( ph -> K e. HL )  | 
						
						
							| 19 | 
							
								18
							 | 
							3ad2ant1 | 
							 |-  ( ( ph /\ Y = Z /\ ps ) -> K e. HL )  | 
						
						
							| 20 | 
							
								1 2 3 4 5 6 7 8 9 11
							 | 
							dalem23 | 
							 |-  ( ( ph /\ Y = Z /\ ps ) -> G e. A )  | 
						
						
							| 21 | 
							
								1 2 3 4 5 6 7 8 9 12
							 | 
							dalem29 | 
							 |-  ( ( ph /\ Y = Z /\ ps ) -> H e. A )  | 
						
						
							| 22 | 
							
								
							 | 
							eqid | 
							 |-  ( Base ` K ) = ( Base ` K )  | 
						
						
							| 23 | 
							
								22 3 4
							 | 
							hlatjcl | 
							 |-  ( ( K e. HL /\ G e. A /\ H e. A ) -> ( G .\/ H ) e. ( Base ` K ) )  | 
						
						
							| 24 | 
							
								19 20 21 23
							 | 
							syl3anc | 
							 |-  ( ( ph /\ Y = Z /\ ps ) -> ( G .\/ H ) e. ( Base ` K ) )  | 
						
						
							| 25 | 
							
								1 3 4
							 | 
							dalempjqeb | 
							 |-  ( ph -> ( P .\/ Q ) e. ( Base ` K ) )  | 
						
						
							| 26 | 
							
								25
							 | 
							3ad2ant1 | 
							 |-  ( ( ph /\ Y = Z /\ ps ) -> ( P .\/ Q ) e. ( Base ` K ) )  | 
						
						
							| 27 | 
							
								22 2 6
							 | 
							latmle2 | 
							 |-  ( ( K e. Lat /\ ( G .\/ H ) e. ( Base ` K ) /\ ( P .\/ Q ) e. ( Base ` K ) ) -> ( ( G .\/ H ) ./\ ( P .\/ Q ) ) .<_ ( P .\/ Q ) )  | 
						
						
							| 28 | 
							
								17 24 26 27
							 | 
							syl3anc | 
							 |-  ( ( ph /\ Y = Z /\ ps ) -> ( ( G .\/ H ) ./\ ( P .\/ Q ) ) .<_ ( P .\/ Q ) )  | 
						
						
							| 29 | 
							
								15 28
							 | 
							eqbrtrrd | 
							 |-  ( ( ph /\ Y = Z /\ ps ) -> ( ( G .\/ H ) ./\ B ) .<_ ( P .\/ Q ) )  | 
						
						
							| 30 | 
							
								1 2 3 4 5 6 7 8 9 11 12 13 14
							 | 
							dalem56 | 
							 |-  ( ( ph /\ Y = Z /\ ps ) -> ( ( G .\/ H ) ./\ ( S .\/ T ) ) = ( ( G .\/ H ) ./\ B ) )  | 
						
						
							| 31 | 
							
								1 3 4
							 | 
							dalemsjteb | 
							 |-  ( ph -> ( S .\/ T ) e. ( Base ` K ) )  | 
						
						
							| 32 | 
							
								31
							 | 
							3ad2ant1 | 
							 |-  ( ( ph /\ Y = Z /\ ps ) -> ( S .\/ T ) e. ( Base ` K ) )  | 
						
						
							| 33 | 
							
								22 2 6
							 | 
							latmle2 | 
							 |-  ( ( K e. Lat /\ ( G .\/ H ) e. ( Base ` K ) /\ ( S .\/ T ) e. ( Base ` K ) ) -> ( ( G .\/ H ) ./\ ( S .\/ T ) ) .<_ ( S .\/ T ) )  | 
						
						
							| 34 | 
							
								17 24 32 33
							 | 
							syl3anc | 
							 |-  ( ( ph /\ Y = Z /\ ps ) -> ( ( G .\/ H ) ./\ ( S .\/ T ) ) .<_ ( S .\/ T ) )  | 
						
						
							| 35 | 
							
								30 34
							 | 
							eqbrtrrd | 
							 |-  ( ( ph /\ Y = Z /\ ps ) -> ( ( G .\/ H ) ./\ B ) .<_ ( S .\/ T ) )  | 
						
						
							| 36 | 
							
								1 2 3 4 5 6 7 8 9 11 12 13 14
							 | 
							dalem54 | 
							 |-  ( ( ph /\ Y = Z /\ ps ) -> ( ( G .\/ H ) ./\ B ) e. A )  | 
						
						
							| 37 | 
							
								22 4
							 | 
							atbase | 
							 |-  ( ( ( G .\/ H ) ./\ B ) e. A -> ( ( G .\/ H ) ./\ B ) e. ( Base ` K ) )  | 
						
						
							| 38 | 
							
								36 37
							 | 
							syl | 
							 |-  ( ( ph /\ Y = Z /\ ps ) -> ( ( G .\/ H ) ./\ B ) e. ( Base ` K ) )  | 
						
						
							| 39 | 
							
								22 2 6
							 | 
							latlem12 | 
							 |-  ( ( K e. Lat /\ ( ( ( G .\/ H ) ./\ B ) e. ( Base ` K ) /\ ( P .\/ Q ) e. ( Base ` K ) /\ ( S .\/ T ) e. ( Base ` K ) ) ) -> ( ( ( ( G .\/ H ) ./\ B ) .<_ ( P .\/ Q ) /\ ( ( G .\/ H ) ./\ B ) .<_ ( S .\/ T ) ) <-> ( ( G .\/ H ) ./\ B ) .<_ ( ( P .\/ Q ) ./\ ( S .\/ T ) ) ) )  | 
						
						
							| 40 | 
							
								17 38 26 32 39
							 | 
							syl13anc | 
							 |-  ( ( ph /\ Y = Z /\ ps ) -> ( ( ( ( G .\/ H ) ./\ B ) .<_ ( P .\/ Q ) /\ ( ( G .\/ H ) ./\ B ) .<_ ( S .\/ T ) ) <-> ( ( G .\/ H ) ./\ B ) .<_ ( ( P .\/ Q ) ./\ ( S .\/ T ) ) ) )  | 
						
						
							| 41 | 
							
								29 35 40
							 | 
							mpbi2and | 
							 |-  ( ( ph /\ Y = Z /\ ps ) -> ( ( G .\/ H ) ./\ B ) .<_ ( ( P .\/ Q ) ./\ ( S .\/ T ) ) )  | 
						
						
							| 42 | 
							
								41 10
							 | 
							breqtrrdi | 
							 |-  ( ( ph /\ Y = Z /\ ps ) -> ( ( G .\/ H ) ./\ B ) .<_ D )  | 
						
						
							| 43 | 
							
								
							 | 
							hlatl | 
							 |-  ( K e. HL -> K e. AtLat )  | 
						
						
							| 44 | 
							
								19 43
							 | 
							syl | 
							 |-  ( ( ph /\ Y = Z /\ ps ) -> K e. AtLat )  | 
						
						
							| 45 | 
							
								1 2 3 4 6 7 8 9 10
							 | 
							dalemdea | 
							 |-  ( ph -> D e. A )  | 
						
						
							| 46 | 
							
								45
							 | 
							3ad2ant1 | 
							 |-  ( ( ph /\ Y = Z /\ ps ) -> D e. A )  | 
						
						
							| 47 | 
							
								2 4
							 | 
							atcmp | 
							 |-  ( ( K e. AtLat /\ ( ( G .\/ H ) ./\ B ) e. A /\ D e. A ) -> ( ( ( G .\/ H ) ./\ B ) .<_ D <-> ( ( G .\/ H ) ./\ B ) = D ) )  | 
						
						
							| 48 | 
							
								44 36 46 47
							 | 
							syl3anc | 
							 |-  ( ( ph /\ Y = Z /\ ps ) -> ( ( ( G .\/ H ) ./\ B ) .<_ D <-> ( ( G .\/ H ) ./\ B ) = D ) )  | 
						
						
							| 49 | 
							
								42 48
							 | 
							mpbid | 
							 |-  ( ( ph /\ Y = Z /\ ps ) -> ( ( G .\/ H ) ./\ B ) = D )  | 
						
						
							| 50 | 
							
								
							 | 
							eqid | 
							 |-  ( LLines ` K ) = ( LLines ` K )  | 
						
						
							| 51 | 
							
								1 2 3 4 5 6 50 7 8 9 11 12 13 14
							 | 
							dalem53 | 
							 |-  ( ( ph /\ Y = Z /\ ps ) -> B e. ( LLines ` K ) )  | 
						
						
							| 52 | 
							
								22 50
							 | 
							llnbase | 
							 |-  ( B e. ( LLines ` K ) -> B e. ( Base ` K ) )  | 
						
						
							| 53 | 
							
								51 52
							 | 
							syl | 
							 |-  ( ( ph /\ Y = Z /\ ps ) -> B e. ( Base ` K ) )  | 
						
						
							| 54 | 
							
								22 2 6
							 | 
							latmle2 | 
							 |-  ( ( K e. Lat /\ ( G .\/ H ) e. ( Base ` K ) /\ B e. ( Base ` K ) ) -> ( ( G .\/ H ) ./\ B ) .<_ B )  | 
						
						
							| 55 | 
							
								17 24 53 54
							 | 
							syl3anc | 
							 |-  ( ( ph /\ Y = Z /\ ps ) -> ( ( G .\/ H ) ./\ B ) .<_ B )  | 
						
						
							| 56 | 
							
								49 55
							 | 
							eqbrtrrd | 
							 |-  ( ( ph /\ Y = Z /\ ps ) -> D .<_ B )  |