| Step | Hyp | Ref | Expression | 
						
							| 1 |  | eqid |  |-  ( Vtx ` G ) = ( Vtx ` G ) | 
						
							| 2 |  | eqid |  |-  ( iEdg ` G ) = ( iEdg ` G ) | 
						
							| 3 | 1 2 | upwlkbprop |  |-  ( F ( UPWalks ` G ) P -> ( G e. _V /\ F e. _V /\ P e. _V ) ) | 
						
							| 4 |  | idd |  |-  ( ( G e. _V /\ F e. _V /\ P e. _V ) -> ( F e. Word dom ( iEdg ` G ) -> F e. Word dom ( iEdg ` G ) ) ) | 
						
							| 5 |  | idd |  |-  ( ( G e. _V /\ F e. _V /\ P e. _V ) -> ( P : ( 0 ... ( # ` F ) ) --> ( Vtx ` G ) -> P : ( 0 ... ( # ` F ) ) --> ( Vtx ` G ) ) ) | 
						
							| 6 |  | ifpprsnss |  |-  ( ( ( iEdg ` G ) ` ( F ` k ) ) = { ( P ` k ) , ( P ` ( k + 1 ) ) } -> if- ( ( P ` k ) = ( P ` ( k + 1 ) ) , ( ( iEdg ` G ) ` ( F ` k ) ) = { ( P ` k ) } , { ( P ` k ) , ( P ` ( k + 1 ) ) } C_ ( ( iEdg ` G ) ` ( F ` k ) ) ) ) | 
						
							| 7 | 6 | a1i |  |-  ( ( ( G e. _V /\ F e. _V /\ P e. _V ) /\ k e. ( 0 ..^ ( # ` F ) ) ) -> ( ( ( iEdg ` G ) ` ( F ` k ) ) = { ( P ` k ) , ( P ` ( k + 1 ) ) } -> if- ( ( P ` k ) = ( P ` ( k + 1 ) ) , ( ( iEdg ` G ) ` ( F ` k ) ) = { ( P ` k ) } , { ( P ` k ) , ( P ` ( k + 1 ) ) } C_ ( ( iEdg ` G ) ` ( F ` k ) ) ) ) ) | 
						
							| 8 | 7 | ralimdva |  |-  ( ( G e. _V /\ F e. _V /\ P e. _V ) -> ( A. k e. ( 0 ..^ ( # ` F ) ) ( ( iEdg ` G ) ` ( F ` k ) ) = { ( P ` k ) , ( P ` ( k + 1 ) ) } -> A. k e. ( 0 ..^ ( # ` F ) ) if- ( ( P ` k ) = ( P ` ( k + 1 ) ) , ( ( iEdg ` G ) ` ( F ` k ) ) = { ( P ` k ) } , { ( P ` k ) , ( P ` ( k + 1 ) ) } C_ ( ( iEdg ` G ) ` ( F ` k ) ) ) ) ) | 
						
							| 9 | 4 5 8 | 3anim123d |  |-  ( ( G e. _V /\ F e. _V /\ P e. _V ) -> ( ( F e. Word dom ( iEdg ` G ) /\ P : ( 0 ... ( # ` F ) ) --> ( Vtx ` G ) /\ A. k e. ( 0 ..^ ( # ` F ) ) ( ( iEdg ` G ) ` ( F ` k ) ) = { ( P ` k ) , ( P ` ( k + 1 ) ) } ) -> ( F e. Word dom ( iEdg ` G ) /\ P : ( 0 ... ( # ` F ) ) --> ( Vtx ` G ) /\ A. k e. ( 0 ..^ ( # ` F ) ) if- ( ( P ` k ) = ( P ` ( k + 1 ) ) , ( ( iEdg ` G ) ` ( F ` k ) ) = { ( P ` k ) } , { ( P ` k ) , ( P ` ( k + 1 ) ) } C_ ( ( iEdg ` G ) ` ( F ` k ) ) ) ) ) ) | 
						
							| 10 | 1 2 | isupwlk |  |-  ( ( G e. _V /\ F e. _V /\ P e. _V ) -> ( F ( UPWalks ` G ) P <-> ( F e. Word dom ( iEdg ` G ) /\ P : ( 0 ... ( # ` F ) ) --> ( Vtx ` G ) /\ A. k e. ( 0 ..^ ( # ` F ) ) ( ( iEdg ` G ) ` ( F ` k ) ) = { ( P ` k ) , ( P ` ( k + 1 ) ) } ) ) ) | 
						
							| 11 | 1 2 | iswlk |  |-  ( ( G e. _V /\ F e. _V /\ P e. _V ) -> ( F ( Walks ` G ) P <-> ( F e. Word dom ( iEdg ` G ) /\ P : ( 0 ... ( # ` F ) ) --> ( Vtx ` G ) /\ A. k e. ( 0 ..^ ( # ` F ) ) if- ( ( P ` k ) = ( P ` ( k + 1 ) ) , ( ( iEdg ` G ) ` ( F ` k ) ) = { ( P ` k ) } , { ( P ` k ) , ( P ` ( k + 1 ) ) } C_ ( ( iEdg ` G ) ` ( F ` k ) ) ) ) ) ) | 
						
							| 12 | 9 10 11 | 3imtr4d |  |-  ( ( G e. _V /\ F e. _V /\ P e. _V ) -> ( F ( UPWalks ` G ) P -> F ( Walks ` G ) P ) ) | 
						
							| 13 | 3 12 | mpcom |  |-  ( F ( UPWalks ` G ) P -> F ( Walks ` G ) P ) |