| Step | Hyp | Ref | Expression | 
						
							| 1 |  | upgrtrls.v |  |-  V = ( Vtx ` G ) | 
						
							| 2 |  | upgrtrls.i |  |-  I = ( iEdg ` G ) | 
						
							| 3 |  | trlsfval |  |-  ( Trails ` G ) = { <. f , p >. | ( f ( Walks ` G ) p /\ Fun `' f ) } | 
						
							| 4 | 1 2 | upgriswlk |  |-  ( G e. UPGraph -> ( f ( Walks ` G ) p <-> ( f e. Word dom I /\ p : ( 0 ... ( # ` f ) ) --> V /\ A. k e. ( 0 ..^ ( # ` f ) ) ( I ` ( f ` k ) ) = { ( p ` k ) , ( p ` ( k + 1 ) ) } ) ) ) | 
						
							| 5 | 4 | anbi1d |  |-  ( G e. UPGraph -> ( ( f ( Walks ` G ) p /\ Fun `' f ) <-> ( ( f e. Word dom I /\ p : ( 0 ... ( # ` f ) ) --> V /\ A. k e. ( 0 ..^ ( # ` f ) ) ( I ` ( f ` k ) ) = { ( p ` k ) , ( p ` ( k + 1 ) ) } ) /\ Fun `' f ) ) ) | 
						
							| 6 |  | an32 |  |-  ( ( ( f e. Word dom I /\ ( p : ( 0 ... ( # ` f ) ) --> V /\ A. k e. ( 0 ..^ ( # ` f ) ) ( I ` ( f ` k ) ) = { ( p ` k ) , ( p ` ( k + 1 ) ) } ) ) /\ Fun `' f ) <-> ( ( f e. Word dom I /\ Fun `' f ) /\ ( p : ( 0 ... ( # ` f ) ) --> V /\ A. k e. ( 0 ..^ ( # ` f ) ) ( I ` ( f ` k ) ) = { ( p ` k ) , ( p ` ( k + 1 ) ) } ) ) ) | 
						
							| 7 |  | 3anass |  |-  ( ( f e. Word dom I /\ p : ( 0 ... ( # ` f ) ) --> V /\ A. k e. ( 0 ..^ ( # ` f ) ) ( I ` ( f ` k ) ) = { ( p ` k ) , ( p ` ( k + 1 ) ) } ) <-> ( f e. Word dom I /\ ( p : ( 0 ... ( # ` f ) ) --> V /\ A. k e. ( 0 ..^ ( # ` f ) ) ( I ` ( f ` k ) ) = { ( p ` k ) , ( p ` ( k + 1 ) ) } ) ) ) | 
						
							| 8 | 7 | anbi1i |  |-  ( ( ( f e. Word dom I /\ p : ( 0 ... ( # ` f ) ) --> V /\ A. k e. ( 0 ..^ ( # ` f ) ) ( I ` ( f ` k ) ) = { ( p ` k ) , ( p ` ( k + 1 ) ) } ) /\ Fun `' f ) <-> ( ( f e. Word dom I /\ ( p : ( 0 ... ( # ` f ) ) --> V /\ A. k e. ( 0 ..^ ( # ` f ) ) ( I ` ( f ` k ) ) = { ( p ` k ) , ( p ` ( k + 1 ) ) } ) ) /\ Fun `' f ) ) | 
						
							| 9 |  | 3anass |  |-  ( ( ( f e. Word dom I /\ Fun `' f ) /\ p : ( 0 ... ( # ` f ) ) --> V /\ A. k e. ( 0 ..^ ( # ` f ) ) ( I ` ( f ` k ) ) = { ( p ` k ) , ( p ` ( k + 1 ) ) } ) <-> ( ( f e. Word dom I /\ Fun `' f ) /\ ( p : ( 0 ... ( # ` f ) ) --> V /\ A. k e. ( 0 ..^ ( # ` f ) ) ( I ` ( f ` k ) ) = { ( p ` k ) , ( p ` ( k + 1 ) ) } ) ) ) | 
						
							| 10 | 6 8 9 | 3bitr4i |  |-  ( ( ( f e. Word dom I /\ p : ( 0 ... ( # ` f ) ) --> V /\ A. k e. ( 0 ..^ ( # ` f ) ) ( I ` ( f ` k ) ) = { ( p ` k ) , ( p ` ( k + 1 ) ) } ) /\ Fun `' f ) <-> ( ( f e. Word dom I /\ Fun `' f ) /\ p : ( 0 ... ( # ` f ) ) --> V /\ A. k e. ( 0 ..^ ( # ` f ) ) ( I ` ( f ` k ) ) = { ( p ` k ) , ( p ` ( k + 1 ) ) } ) ) | 
						
							| 11 | 5 10 | bitrdi |  |-  ( G e. UPGraph -> ( ( f ( Walks ` G ) p /\ Fun `' f ) <-> ( ( f e. Word dom I /\ Fun `' f ) /\ p : ( 0 ... ( # ` f ) ) --> V /\ A. k e. ( 0 ..^ ( # ` f ) ) ( I ` ( f ` k ) ) = { ( p ` k ) , ( p ` ( k + 1 ) ) } ) ) ) | 
						
							| 12 | 11 | opabbidv |  |-  ( G e. UPGraph -> { <. f , p >. | ( f ( Walks ` G ) p /\ Fun `' f ) } = { <. f , p >. | ( ( f e. Word dom I /\ Fun `' f ) /\ p : ( 0 ... ( # ` f ) ) --> V /\ A. k e. ( 0 ..^ ( # ` f ) ) ( I ` ( f ` k ) ) = { ( p ` k ) , ( p ` ( k + 1 ) ) } ) } ) | 
						
							| 13 | 3 12 | eqtrid |  |-  ( G e. UPGraph -> ( Trails ` G ) = { <. f , p >. | ( ( f e. Word dom I /\ Fun `' f ) /\ p : ( 0 ... ( # ` f ) ) --> V /\ A. k e. ( 0 ..^ ( # ` f ) ) ( I ` ( f ` k ) ) = { ( p ` k ) , ( p ` ( k + 1 ) ) } ) } ) |