The goal of this book's graph theory instruction is not to memorize definitions. Whenever you forget a definition, you can refer to this page, and doing so does not mean cheating at all (the page title is merely an idiom).
Note that this page is not for teaching; the content is summarized so that only someone already familiar with it can recall it. For learning, use the lessons.
Independence number or maximum independent set (alpha \(\alpha\)): The maximum number of vertices in a graph that have no edges between them.
Maximum matching (alpha prime \(\alpha^{\prime}\)): The maximum number of edges in a graph such that no two edges share a common vertex.
Minimum vertex cover (beta \(\beta\)): The minimum number of vertices in a graph such that every edge has at least one endpoint in these vertices.
Minimum edge cover (beta prime \(\beta^{\prime}\)): The minimum number of edges in a graph such that every vertex is an endpoint of at least one of these edges.
Chromatic number (chi \(\chi\)): The minimum number of colors required to color the vertices of a graph such that no two adjacent vertices have the same color.
Edge chromatic number (chi prime \(\chi^{\prime}\)): The minimum number of colors required to color the edges of a graph such that no two incident edges have the same color.
Vertex connectivity (kappa \(\kappa\)) The minimum number of vertices whose removal disconnects the graph.
Edge connectivity (kappa prime \(\kappa^{\prime}\)) The minimum number of edges whose removal disconnects the graph.
Clique number (omega \(\omega\)): The maximum number of vertices in a graph that are pairwise adjacent.
Minimum degree (small delta \(\delta\)): The minimum number of edges incident to any vertex in the graph.
Maximum degree (capital delta \(\Delta\)): The maximum number of edges incident to any vertex in the graph.