Description: A graph with at least one vertex is a set. (Contributed by AV, 2-Mar-2021)
| Ref | Expression | ||
|---|---|---|---|
| Hypothesis | 1vgrex.v | |- V = ( Vtx ` G ) |
|
| Assertion | 1vgrex | |- ( N e. V -> G e. _V ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | 1vgrex.v | |- V = ( Vtx ` G ) |
|
| 2 | elfvex | |- ( N e. ( Vtx ` G ) -> G e. _V ) |
|
| 3 | 2 1 | eleq2s | |- ( N e. V -> G e. _V ) |