| Step | 
						Hyp | 
						Ref | 
						Expression | 
					
						
							| 1 | 
							
								
							 | 
							iscgra.p | 
							 |-  P = ( Base ` G )  | 
						
						
							| 2 | 
							
								
							 | 
							iscgra.i | 
							 |-  I = ( Itv ` G )  | 
						
						
							| 3 | 
							
								
							 | 
							iscgra.k | 
							 |-  K = ( hlG ` G )  | 
						
						
							| 4 | 
							
								
							 | 
							iscgra.g | 
							 |-  ( ph -> G e. TarskiG )  | 
						
						
							| 5 | 
							
								
							 | 
							iscgra.a | 
							 |-  ( ph -> A e. P )  | 
						
						
							| 6 | 
							
								
							 | 
							iscgra.b | 
							 |-  ( ph -> B e. P )  | 
						
						
							| 7 | 
							
								
							 | 
							iscgra.c | 
							 |-  ( ph -> C e. P )  | 
						
						
							| 8 | 
							
								
							 | 
							iscgra.d | 
							 |-  ( ph -> D e. P )  | 
						
						
							| 9 | 
							
								
							 | 
							iscgra.e | 
							 |-  ( ph -> E e. P )  | 
						
						
							| 10 | 
							
								
							 | 
							iscgra.f | 
							 |-  ( ph -> F e. P )  | 
						
						
							| 11 | 
							
								
							 | 
							iscgrad.x | 
							 |-  ( ph -> X e. P )  | 
						
						
							| 12 | 
							
								
							 | 
							iscgrad.y | 
							 |-  ( ph -> Y e. P )  | 
						
						
							| 13 | 
							
								
							 | 
							iscgrad.1 | 
							 |-  ( ph -> <" A B C "> ( cgrG ` G ) <" X E Y "> )  | 
						
						
							| 14 | 
							
								
							 | 
							iscgrad.2 | 
							 |-  ( ph -> X ( K ` E ) D )  | 
						
						
							| 15 | 
							
								
							 | 
							iscgrad.3 | 
							 |-  ( ph -> Y ( K ` E ) F )  | 
						
						
							| 16 | 
							
								
							 | 
							id | 
							 |-  ( x = X -> x = X )  | 
						
						
							| 17 | 
							
								
							 | 
							eqidd | 
							 |-  ( x = X -> E = E )  | 
						
						
							| 18 | 
							
								
							 | 
							eqidd | 
							 |-  ( x = X -> y = y )  | 
						
						
							| 19 | 
							
								16 17 18
							 | 
							s3eqd | 
							 |-  ( x = X -> <" x E y "> = <" X E y "> )  | 
						
						
							| 20 | 
							
								19
							 | 
							breq2d | 
							 |-  ( x = X -> ( <" A B C "> ( cgrG ` G ) <" x E y "> <-> <" A B C "> ( cgrG ` G ) <" X E y "> ) )  | 
						
						
							| 21 | 
							
								
							 | 
							breq1 | 
							 |-  ( x = X -> ( x ( K ` E ) D <-> X ( K ` E ) D ) )  | 
						
						
							| 22 | 
							
								20 21
							 | 
							3anbi12d | 
							 |-  ( x = X -> ( ( <" A B C "> ( cgrG ` G ) <" x E y "> /\ x ( K ` E ) D /\ y ( K ` E ) F ) <-> ( <" A B C "> ( cgrG ` G ) <" X E y "> /\ X ( K ` E ) D /\ y ( K ` E ) F ) ) )  | 
						
						
							| 23 | 
							
								
							 | 
							eqidd | 
							 |-  ( y = Y -> X = X )  | 
						
						
							| 24 | 
							
								
							 | 
							eqidd | 
							 |-  ( y = Y -> E = E )  | 
						
						
							| 25 | 
							
								
							 | 
							id | 
							 |-  ( y = Y -> y = Y )  | 
						
						
							| 26 | 
							
								23 24 25
							 | 
							s3eqd | 
							 |-  ( y = Y -> <" X E y "> = <" X E Y "> )  | 
						
						
							| 27 | 
							
								26
							 | 
							breq2d | 
							 |-  ( y = Y -> ( <" A B C "> ( cgrG ` G ) <" X E y "> <-> <" A B C "> ( cgrG ` G ) <" X E Y "> ) )  | 
						
						
							| 28 | 
							
								
							 | 
							breq1 | 
							 |-  ( y = Y -> ( y ( K ` E ) F <-> Y ( K ` E ) F ) )  | 
						
						
							| 29 | 
							
								27 28
							 | 
							3anbi13d | 
							 |-  ( y = Y -> ( ( <" A B C "> ( cgrG ` G ) <" X E y "> /\ X ( K ` E ) D /\ y ( K ` E ) F ) <-> ( <" A B C "> ( cgrG ` G ) <" X E Y "> /\ X ( K ` E ) D /\ Y ( K ` E ) F ) ) )  | 
						
						
							| 30 | 
							
								22 29
							 | 
							rspc2ev | 
							 |-  ( ( X e. P /\ Y e. P /\ ( <" A B C "> ( cgrG ` G ) <" X E Y "> /\ X ( K ` E ) D /\ Y ( K ` E ) F ) ) -> E. x e. P E. y e. P ( <" A B C "> ( cgrG ` G ) <" x E y "> /\ x ( K ` E ) D /\ y ( K ` E ) F ) )  | 
						
						
							| 31 | 
							
								11 12 13 14 15 30
							 | 
							syl113anc | 
							 |-  ( ph -> E. x e. P E. y e. P ( <" A B C "> ( cgrG ` G ) <" x E y "> /\ x ( K ` E ) D /\ y ( K ` E ) F ) )  | 
						
						
							| 32 | 
							
								1 2 3 4 5 6 7 8 9 10
							 | 
							iscgra | 
							 |-  ( ph -> ( <" A B C "> ( cgrA ` G ) <" D E F "> <-> E. x e. P E. y e. P ( <" A B C "> ( cgrG ` G ) <" x E y "> /\ x ( K ` E ) D /\ y ( K ` E ) F ) ) )  | 
						
						
							| 33 | 
							
								31 32
							 | 
							mpbird | 
							 |-  ( ph -> <" A B C "> ( cgrA ` G ) <" D E F "> )  |