| 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 | 
							
								
							 | 
							dalem44.m | 
							 |-  ./\ = ( meet ` K )  | 
						
						
							| 7 | 
							
								
							 | 
							dalem44.o | 
							 |-  O = ( LPlanes ` K )  | 
						
						
							| 8 | 
							
								
							 | 
							dalem44.y | 
							 |-  Y = ( ( P .\/ Q ) .\/ R )  | 
						
						
							| 9 | 
							
								
							 | 
							dalem44.z | 
							 |-  Z = ( ( S .\/ T ) .\/ U )  | 
						
						
							| 10 | 
							
								
							 | 
							dalem44.g | 
							 |-  G = ( ( c .\/ P ) ./\ ( d .\/ S ) )  | 
						
						
							| 11 | 
							
								
							 | 
							dalem44.h | 
							 |-  H = ( ( c .\/ Q ) ./\ ( d .\/ T ) )  | 
						
						
							| 12 | 
							
								
							 | 
							dalem44.i | 
							 |-  I = ( ( c .\/ R ) ./\ ( d .\/ U ) )  | 
						
						
							| 13 | 
							
								1
							 | 
							dalemkehl | 
							 |-  ( ph -> K e. HL )  | 
						
						
							| 14 | 
							
								13
							 | 
							3ad2ant1 | 
							 |-  ( ( ph /\ Y = Z /\ ps ) -> K e. HL )  | 
						
						
							| 15 | 
							
								5
							 | 
							dalemccea | 
							 |-  ( ps -> c e. A )  | 
						
						
							| 16 | 
							
								15
							 | 
							3ad2ant3 | 
							 |-  ( ( ph /\ Y = Z /\ ps ) -> c e. A )  | 
						
						
							| 17 | 
							
								14 16
							 | 
							jca | 
							 |-  ( ( ph /\ Y = Z /\ ps ) -> ( K e. HL /\ c e. A ) )  | 
						
						
							| 18 | 
							
								1 2 3 4 5 6 7 8 9 10
							 | 
							dalem23 | 
							 |-  ( ( ph /\ Y = Z /\ ps ) -> G e. A )  | 
						
						
							| 19 | 
							
								1 2 3 4 5 6 7 8 9 11
							 | 
							dalem29 | 
							 |-  ( ( ph /\ Y = Z /\ ps ) -> H e. A )  | 
						
						
							| 20 | 
							
								1 2 3 4 5 6 7 8 9 12
							 | 
							dalem34 | 
							 |-  ( ( ph /\ Y = Z /\ ps ) -> I e. A )  | 
						
						
							| 21 | 
							
								18 19 20
							 | 
							3jca | 
							 |-  ( ( ph /\ Y = Z /\ ps ) -> ( G e. A /\ H e. A /\ I e. A ) )  | 
						
						
							| 22 | 
							
								1
							 | 
							dalempea | 
							 |-  ( ph -> P e. A )  | 
						
						
							| 23 | 
							
								1
							 | 
							dalemqea | 
							 |-  ( ph -> Q e. A )  | 
						
						
							| 24 | 
							
								1
							 | 
							dalemrea | 
							 |-  ( ph -> R e. A )  | 
						
						
							| 25 | 
							
								22 23 24
							 | 
							3jca | 
							 |-  ( ph -> ( P e. A /\ Q e. A /\ R e. A ) )  | 
						
						
							| 26 | 
							
								25
							 | 
							3ad2ant1 | 
							 |-  ( ( ph /\ Y = Z /\ ps ) -> ( P e. A /\ Q e. A /\ R e. A ) )  | 
						
						
							| 27 | 
							
								17 21 26
							 | 
							3jca | 
							 |-  ( ( ph /\ Y = Z /\ ps ) -> ( ( K e. HL /\ c e. A ) /\ ( G e. A /\ H e. A /\ I e. A ) /\ ( P e. A /\ Q e. A /\ R e. A ) ) )  | 
						
						
							| 28 | 
							
								1 2 3 4 5 6 7 8 9 10 11 12
							 | 
							dalem42 | 
							 |-  ( ( ph /\ Y = Z /\ ps ) -> ( ( G .\/ H ) .\/ I ) e. O )  | 
						
						
							| 29 | 
							
								1
							 | 
							dalemyeo | 
							 |-  ( ph -> Y e. O )  | 
						
						
							| 30 | 
							
								29
							 | 
							3ad2ant1 | 
							 |-  ( ( ph /\ Y = Z /\ ps ) -> Y e. O )  | 
						
						
							| 31 | 
							
								28 30
							 | 
							jca | 
							 |-  ( ( ph /\ Y = Z /\ ps ) -> ( ( ( G .\/ H ) .\/ I ) e. O /\ Y e. O ) )  | 
						
						
							| 32 | 
							
								1 2 3 4 5 6 7 8 9 10 11 12
							 | 
							dalem45 | 
							 |-  ( ( ph /\ Y = Z /\ ps ) -> -. c .<_ ( G .\/ H ) )  | 
						
						
							| 33 | 
							
								1 2 3 4 5 6 7 8 9 10 11 12
							 | 
							dalem46 | 
							 |-  ( ( ph /\ Y = Z /\ ps ) -> -. c .<_ ( H .\/ I ) )  | 
						
						
							| 34 | 
							
								1 2 3 4 5 6 7 8 9 10 11 12
							 | 
							dalem47 | 
							 |-  ( ( ph /\ Y = Z /\ ps ) -> -. c .<_ ( I .\/ G ) )  | 
						
						
							| 35 | 
							
								32 33 34
							 | 
							3jca | 
							 |-  ( ( ph /\ Y = Z /\ ps ) -> ( -. c .<_ ( G .\/ H ) /\ -. c .<_ ( H .\/ I ) /\ -. c .<_ ( I .\/ G ) ) )  | 
						
						
							| 36 | 
							
								1 2 3 4 5 6 7 8 9 10 11 12
							 | 
							dalem48 | 
							 |-  ( ( ph /\ ps ) -> -. c .<_ ( P .\/ Q ) )  | 
						
						
							| 37 | 
							
								1 2 3 4 5 6 7 8 9 10 11 12
							 | 
							dalem49 | 
							 |-  ( ( ph /\ ps ) -> -. c .<_ ( Q .\/ R ) )  | 
						
						
							| 38 | 
							
								1 2 3 4 5 6 7 8 9 10 11 12
							 | 
							dalem50 | 
							 |-  ( ( ph /\ ps ) -> -. c .<_ ( R .\/ P ) )  | 
						
						
							| 39 | 
							
								36 37 38
							 | 
							3jca | 
							 |-  ( ( ph /\ ps ) -> ( -. c .<_ ( P .\/ Q ) /\ -. c .<_ ( Q .\/ R ) /\ -. c .<_ ( R .\/ P ) ) )  | 
						
						
							| 40 | 
							
								39
							 | 
							3adant2 | 
							 |-  ( ( ph /\ Y = Z /\ ps ) -> ( -. c .<_ ( P .\/ Q ) /\ -. c .<_ ( Q .\/ R ) /\ -. c .<_ ( R .\/ P ) ) )  | 
						
						
							| 41 | 
							
								1 2 3 4 5 6 7 8 9 10
							 | 
							dalem27 | 
							 |-  ( ( ph /\ Y = Z /\ ps ) -> c .<_ ( G .\/ P ) )  | 
						
						
							| 42 | 
							
								1 2 3 4 5 6 7 8 9 11
							 | 
							dalem32 | 
							 |-  ( ( ph /\ Y = Z /\ ps ) -> c .<_ ( H .\/ Q ) )  | 
						
						
							| 43 | 
							
								1 2 3 4 5 6 7 8 9 12
							 | 
							dalem36 | 
							 |-  ( ( ph /\ Y = Z /\ ps ) -> c .<_ ( I .\/ R ) )  | 
						
						
							| 44 | 
							
								41 42 43
							 | 
							3jca | 
							 |-  ( ( ph /\ Y = Z /\ ps ) -> ( c .<_ ( G .\/ P ) /\ c .<_ ( H .\/ Q ) /\ c .<_ ( I .\/ R ) ) )  | 
						
						
							| 45 | 
							
								35 40 44
							 | 
							3jca | 
							 |-  ( ( ph /\ Y = Z /\ ps ) -> ( ( -. c .<_ ( G .\/ H ) /\ -. c .<_ ( H .\/ I ) /\ -. c .<_ ( I .\/ G ) ) /\ ( -. c .<_ ( P .\/ Q ) /\ -. c .<_ ( Q .\/ R ) /\ -. c .<_ ( R .\/ P ) ) /\ ( c .<_ ( G .\/ P ) /\ c .<_ ( H .\/ Q ) /\ c .<_ ( I .\/ R ) ) ) )  | 
						
						
							| 46 | 
							
								27 31 45
							 | 
							3jca | 
							 |-  ( ( ph /\ Y = Z /\ ps ) -> ( ( ( K e. HL /\ c e. A ) /\ ( G e. A /\ H e. A /\ I e. A ) /\ ( P e. A /\ Q e. A /\ R e. A ) ) /\ ( ( ( G .\/ H ) .\/ I ) e. O /\ Y e. O ) /\ ( ( -. c .<_ ( G .\/ H ) /\ -. c .<_ ( H .\/ I ) /\ -. c .<_ ( I .\/ G ) ) /\ ( -. c .<_ ( P .\/ Q ) /\ -. c .<_ ( Q .\/ R ) /\ -. c .<_ ( R .\/ P ) ) /\ ( c .<_ ( G .\/ P ) /\ c .<_ ( H .\/ Q ) /\ c .<_ ( I .\/ R ) ) ) ) )  | 
						
						
							| 47 | 
							
								1 2 3 4 5 6 7 8 9 10 11 12
							 | 
							dalem43 | 
							 |-  ( ( ph /\ Y = Z /\ ps ) -> ( ( G .\/ H ) .\/ I ) =/= Y )  | 
						
						
							| 48 | 
							
								46 47
							 | 
							jca | 
							 |-  ( ( ph /\ Y = Z /\ ps ) -> ( ( ( ( K e. HL /\ c e. A ) /\ ( G e. A /\ H e. A /\ I e. A ) /\ ( P e. A /\ Q e. A /\ R e. A ) ) /\ ( ( ( G .\/ H ) .\/ I ) e. O /\ Y e. O ) /\ ( ( -. c .<_ ( G .\/ H ) /\ -. c .<_ ( H .\/ I ) /\ -. c .<_ ( I .\/ G ) ) /\ ( -. c .<_ ( P .\/ Q ) /\ -. c .<_ ( Q .\/ R ) /\ -. c .<_ ( R .\/ P ) ) /\ ( c .<_ ( G .\/ P ) /\ c .<_ ( H .\/ Q ) /\ c .<_ ( I .\/ R ) ) ) ) /\ ( ( G .\/ H ) .\/ I ) =/= Y ) )  |