\begin{definition}[Definition:Edge Set]
Let $G = \struct {V, E}$ be a graph.
The set $E$ of edges in $G$ is called the '''edge set'''.
It consists of (unordered) pairs of elements of the vertex set $V$.
It is often convenient to refer to the '''edge set''' for a given graph $G$ as $\map E G$, especially if there is at any one time more than one graph under consideration.
\end{definition}