| 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 | 
							
								
							 | 
							dalem53.m | 
							 |-  ./\ = ( meet ` K )  | 
						
						
							| 7 | 
							
								
							 | 
							dalem53.n | 
							 |-  N = ( LLines ` K )  | 
						
						
							| 8 | 
							
								
							 | 
							dalem53.o | 
							 |-  O = ( LPlanes ` K )  | 
						
						
							| 9 | 
							
								
							 | 
							dalem53.y | 
							 |-  Y = ( ( P .\/ Q ) .\/ R )  | 
						
						
							| 10 | 
							
								
							 | 
							dalem53.z | 
							 |-  Z = ( ( S .\/ T ) .\/ U )  | 
						
						
							| 11 | 
							
								
							 | 
							dalem53.g | 
							 |-  G = ( ( c .\/ P ) ./\ ( d .\/ S ) )  | 
						
						
							| 12 | 
							
								
							 | 
							dalem53.h | 
							 |-  H = ( ( c .\/ Q ) ./\ ( d .\/ T ) )  | 
						
						
							| 13 | 
							
								
							 | 
							dalem53.i | 
							 |-  I = ( ( c .\/ R ) ./\ ( d .\/ U ) )  | 
						
						
							| 14 | 
							
								
							 | 
							dalem53.b1 | 
							 |-  B = ( ( ( G .\/ H ) .\/ I ) ./\ Y )  | 
						
						
							| 15 | 
							
								1 2 3 4 5 6 8 9 10 11 12 13
							 | 
							dalem51 | 
							 |-  ( ( 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 ) )  | 
						
						
							| 16 | 
							
								
							 | 
							eqid | 
							 |-  ( Base ` K ) = ( Base ` K )  | 
						
						
							| 17 | 
							
								16 4
							 | 
							atbase | 
							 |-  ( c e. A -> c e. ( Base ` K ) )  | 
						
						
							| 18 | 
							
								17
							 | 
							anim2i | 
							 |-  ( ( K e. HL /\ c e. A ) -> ( K e. HL /\ c e. ( Base ` K ) ) )  | 
						
						
							| 19 | 
							
								18
							 | 
							3anim1i | 
							 |-  ( ( ( K e. HL /\ c e. A ) /\ ( G e. A /\ H e. A /\ I e. A ) /\ ( P e. A /\ Q e. A /\ R e. A ) ) -> ( ( K e. HL /\ c e. ( Base ` K ) ) /\ ( G e. A /\ H e. A /\ I e. A ) /\ ( P e. A /\ Q e. A /\ R e. A ) ) )  | 
						
						
							| 20 | 
							
								
							 | 
							biid | 
							 |-  ( ( ( ( K e. HL /\ c e. ( Base ` K ) ) /\ ( 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 ) ) ) ) <-> ( ( ( K e. HL /\ c e. ( Base ` K ) ) /\ ( 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 ) ) ) ) )  | 
						
						
							| 21 | 
							
								
							 | 
							eqid | 
							 |-  ( ( G .\/ H ) .\/ I ) = ( ( G .\/ H ) .\/ I )  | 
						
						
							| 22 | 
							
								20 2 3 4 6 7 8 21 9 14
							 | 
							dalem15 | 
							 |-  ( ( ( ( ( K e. HL /\ c e. ( Base ` K ) ) /\ ( 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 ) -> B e. N )  | 
						
						
							| 23 | 
							
								19 22
							 | 
							syl3anl1 | 
							 |-  ( ( ( ( ( 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 ) -> B e. N )  | 
						
						
							| 24 | 
							
								15 23
							 | 
							syl | 
							 |-  ( ( ph /\ Y = Z /\ ps ) -> B e. N )  |