In
graph theory, an
independent set or
stable set is a set of
vertices in a
graph, no two of which are adjacent. That is, it is a set
I of vertices such that for every two vertices in
I, there is no
edge connecting the two. Equivalently, each edge in the graph has at most one endpoint in
I. The size of an independent set is the number of vertices it contains. Independent sets have also been called internally stable sets.