Description: If a class is a subgraph of another class, both classes are sets. (Contributed by AV, 16-Nov-2020)
Ref | Expression | ||
---|---|---|---|
Assertion | subgrv | |- ( S SubGraph G -> ( S e. _V /\ G e. _V ) ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | relsubgr | |- Rel SubGraph |
|
2 | 1 | brrelex12i | |- ( S SubGraph G -> ( S e. _V /\ G e. _V ) ) |