| Step | Hyp | Ref | Expression | 
						
							| 1 |  | tngbas.t |  |-  T = ( G toNrmGrp N ) | 
						
							| 2 |  | tnglem.e |  |-  E = Slot ( E ` ndx ) | 
						
							| 3 |  | tnglem.t |  |-  ( E ` ndx ) =/= ( TopSet ` ndx ) | 
						
							| 4 |  | tnglem.d |  |-  ( E ` ndx ) =/= ( dist ` ndx ) | 
						
							| 5 | 2 4 | setsnid |  |-  ( E ` G ) = ( E ` ( G sSet <. ( dist ` ndx ) , ( N o. ( -g ` G ) ) >. ) ) | 
						
							| 6 | 2 3 | setsnid |  |-  ( E ` ( G sSet <. ( dist ` ndx ) , ( N o. ( -g ` G ) ) >. ) ) = ( E ` ( ( G sSet <. ( dist ` ndx ) , ( N o. ( -g ` G ) ) >. ) sSet <. ( TopSet ` ndx ) , ( MetOpen ` ( N o. ( -g ` G ) ) ) >. ) ) | 
						
							| 7 | 5 6 | eqtri |  |-  ( E ` G ) = ( E ` ( ( G sSet <. ( dist ` ndx ) , ( N o. ( -g ` G ) ) >. ) sSet <. ( TopSet ` ndx ) , ( MetOpen ` ( N o. ( -g ` G ) ) ) >. ) ) | 
						
							| 8 |  | eqid |  |-  ( -g ` G ) = ( -g ` G ) | 
						
							| 9 |  | eqid |  |-  ( N o. ( -g ` G ) ) = ( N o. ( -g ` G ) ) | 
						
							| 10 |  | eqid |  |-  ( MetOpen ` ( N o. ( -g ` G ) ) ) = ( MetOpen ` ( N o. ( -g ` G ) ) ) | 
						
							| 11 | 1 8 9 10 | tngval |  |-  ( ( G e. _V /\ N e. V ) -> T = ( ( G sSet <. ( dist ` ndx ) , ( N o. ( -g ` G ) ) >. ) sSet <. ( TopSet ` ndx ) , ( MetOpen ` ( N o. ( -g ` G ) ) ) >. ) ) | 
						
							| 12 | 11 | fveq2d |  |-  ( ( G e. _V /\ N e. V ) -> ( E ` T ) = ( E ` ( ( G sSet <. ( dist ` ndx ) , ( N o. ( -g ` G ) ) >. ) sSet <. ( TopSet ` ndx ) , ( MetOpen ` ( N o. ( -g ` G ) ) ) >. ) ) ) | 
						
							| 13 | 7 12 | eqtr4id |  |-  ( ( G e. _V /\ N e. V ) -> ( E ` G ) = ( E ` T ) ) | 
						
							| 14 | 2 | str0 |  |-  (/) = ( E ` (/) ) | 
						
							| 15 | 14 | eqcomi |  |-  ( E ` (/) ) = (/) | 
						
							| 16 |  | reldmtng |  |-  Rel dom toNrmGrp | 
						
							| 17 | 15 1 16 | oveqprc |  |-  ( -. G e. _V -> ( E ` G ) = ( E ` T ) ) | 
						
							| 18 | 17 | adantr |  |-  ( ( -. G e. _V /\ N e. V ) -> ( E ` G ) = ( E ` T ) ) | 
						
							| 19 | 13 18 | pm2.61ian |  |-  ( N e. V -> ( E ` G ) = ( E ` T ) ) |