| Step |
Hyp |
Ref |
Expression |
| 1 |
|
fusgrfupgrfs.v |
|- V = ( Vtx ` G ) |
| 2 |
|
fusgrfupgrfs.i |
|- I = ( iEdg ` G ) |
| 3 |
|
fusgrusgr |
|- ( G e. FinUSGraph -> G e. USGraph ) |
| 4 |
|
usgrupgr |
|- ( G e. USGraph -> G e. UPGraph ) |
| 5 |
3 4
|
syl |
|- ( G e. FinUSGraph -> G e. UPGraph ) |
| 6 |
1
|
fusgrvtxfi |
|- ( G e. FinUSGraph -> V e. Fin ) |
| 7 |
|
fusgrfis |
|- ( G e. FinUSGraph -> ( Edg ` G ) e. Fin ) |
| 8 |
|
eqid |
|- ( Edg ` G ) = ( Edg ` G ) |
| 9 |
2 8
|
usgredgffibi |
|- ( G e. USGraph -> ( ( Edg ` G ) e. Fin <-> I e. Fin ) ) |
| 10 |
3 9
|
syl |
|- ( G e. FinUSGraph -> ( ( Edg ` G ) e. Fin <-> I e. Fin ) ) |
| 11 |
7 10
|
mpbid |
|- ( G e. FinUSGraph -> I e. Fin ) |
| 12 |
5 6 11
|
3jca |
|- ( G e. FinUSGraph -> ( G e. UPGraph /\ V e. Fin /\ I e. Fin ) ) |