| Step | Hyp | Ref | Expression | 
						
							| 1 |  | israg.p |  |-  P = ( Base ` G ) | 
						
							| 2 |  | israg.d |  |-  .- = ( dist ` G ) | 
						
							| 3 |  | israg.i |  |-  I = ( Itv ` G ) | 
						
							| 4 |  | israg.l |  |-  L = ( LineG ` G ) | 
						
							| 5 |  | israg.s |  |-  S = ( pInvG ` G ) | 
						
							| 6 |  | israg.g |  |-  ( ph -> G e. TarskiG ) | 
						
							| 7 |  | israg.a |  |-  ( ph -> A e. P ) | 
						
							| 8 |  | israg.b |  |-  ( ph -> B e. P ) | 
						
							| 9 |  | israg.c |  |-  ( ph -> C e. P ) | 
						
							| 10 |  | eqid |  |-  ( S ` B ) = ( S ` B ) | 
						
							| 11 | 1 2 3 4 5 6 8 10 | mircinv |  |-  ( ph -> ( ( S ` B ) ` B ) = B ) | 
						
							| 12 | 11 | oveq2d |  |-  ( ph -> ( A .- ( ( S ` B ) ` B ) ) = ( A .- B ) ) | 
						
							| 13 | 12 | eqcomd |  |-  ( ph -> ( A .- B ) = ( A .- ( ( S ` B ) ` B ) ) ) | 
						
							| 14 | 1 2 3 4 5 6 7 8 8 | israg |  |-  ( ph -> ( <" A B B "> e. ( raG ` G ) <-> ( A .- B ) = ( A .- ( ( S ` B ) ` B ) ) ) ) | 
						
							| 15 | 13 14 | mpbird |  |-  ( ph -> <" A B B "> e. ( raG ` G ) ) |