Database
GRAPH THEORY
Vertices and edges
Vertices and indexed edges
Definitions and basic properties
1vgrex
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The vertices and edges of a graph represented as ordered pair
Metamath Proof Explorer
Ascii
Unicode
Theorem
1vgrex
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
Proof
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