Theorem subgrv

Description: If a class is a subgraph of another class, both classes are sets. (Contributed by AV, 16-Nov-2020)

	Ref	Expression
Assertion	subgrv	$$⊢S\mathrm{SubGraph}G\to \left(S\in \mathrm{V}\wedge G\in \mathrm{V}\right)$$

Proof

Step	Hyp	Ref	Expression
1		relsubgr	$$⊢\mathrm{Rel}\mathrm{SubGraph}$$
2	1	brrelex12i	$$⊢S\mathrm{SubGraph}G\to \left(S\in \mathrm{V}\wedge G\in \mathrm{V}\right)$$