ABSTRACT
In this appendix some basic terminology and results from graph theory are introduced. For a more detailed treatment of graph theory, we refer to Bondy and Murty (1976) and West (2001).
C.1 Undirected graphs A graph G is defined as a nonempty finite set V(G) of elements called nodes, a finite set E(G) of elements called edges, and an incidence relation which associates with each edge either one or two nodes called end nodes. Two nodes that are incident with a common edge are called adjacent, as are two edges which are incident with a common node. We will write G = (V, E). An edge is called a loop if the number of its end nodes is one. Two or more edges with the same set of end nodes are said to be parallel. A graph without loops and parallel edges is called a simple graph.
