| Step | Hyp | Ref | Expression | 
						
							| 1 |  | upgrwlkcompim.v |  |-  V = ( Vtx ` G ) | 
						
							| 2 |  | upgrwlkcompim.i |  |-  I = ( iEdg ` G ) | 
						
							| 3 |  | upgrwlkcompim.1 |  |-  F = ( 1st ` W ) | 
						
							| 4 |  | upgrwlkcompim.2 |  |-  P = ( 2nd ` W ) | 
						
							| 5 |  | wlkcpr |  |-  ( W e. ( Walks ` G ) <-> ( 1st ` W ) ( Walks ` G ) ( 2nd ` W ) ) | 
						
							| 6 | 3 4 | breq12i |  |-  ( F ( Walks ` G ) P <-> ( 1st ` W ) ( Walks ` G ) ( 2nd ` W ) ) | 
						
							| 7 | 5 6 | bitr4i |  |-  ( W e. ( Walks ` G ) <-> F ( Walks ` G ) P ) | 
						
							| 8 | 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 ) ) } ) ) ) | 
						
							| 9 | 8 | biimpd |  |-  ( 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 ) ) } ) ) ) | 
						
							| 10 | 7 9 | biimtrid |  |-  ( G e. UPGraph -> ( W e. ( Walks ` G ) -> ( F e. Word dom I /\ P : ( 0 ... ( # ` F ) ) --> V /\ A. k e. ( 0 ..^ ( # ` F ) ) ( I ` ( F ` k ) ) = { ( P ` k ) , ( P ` ( k + 1 ) ) } ) ) ) | 
						
							| 11 | 10 | imp |  |-  ( ( G e. UPGraph /\ W e. ( Walks ` G ) ) -> ( F e. Word dom I /\ P : ( 0 ... ( # ` F ) ) --> V /\ A. k e. ( 0 ..^ ( # ` F ) ) ( I ` ( F ` k ) ) = { ( P ` k ) , ( P ` ( k + 1 ) ) } ) ) |