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 ∈ 𝑉 → 𝐺 ∈ V ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | 1vgrex.v | ⊢ 𝑉 = ( Vtx ‘ 𝐺 ) | |
| 2 | elfvex | ⊢ ( 𝑁 ∈ ( Vtx ‘ 𝐺 ) → 𝐺 ∈ V ) | |
| 3 | 2 1 | eleq2s | ⊢ ( 𝑁 ∈ 𝑉 → 𝐺 ∈ V ) |