Theorem uvtxssvtx

Description: The set of the universal vertices is a subset of the set of all vertices. (Contributed by AV, 23-Dec-2020)

	Ref	Expression
Hypothesis	uvtxel.v	$$⊢V=\mathrm{Vtx}\left(G\right)$$
Assertion	uvtxssvtx	$$⊢\mathrm{UnivVtx}\left(G\right)\subseteq V$$

Proof

Step	Hyp	Ref	Expression
1		uvtxel.v	$$⊢V=\mathrm{Vtx}\left(G\right)$$
2	1	uvtxisvtx	$$⊢n\in \mathrm{UnivVtx}\left(G\right)\to n\in V$$
3	2	ssriv	$$⊢\mathrm{UnivVtx}\left(G\right)\subseteq V$$