In discrete mathematics, particularly in graph theory, a graph is a structure consisting of a set of objects where some pairs of the objects are in some sense "related". The objects are represented by abstractions called 展开

Oriented graph
One definition of an oriented graph is that it is a directed graph in which at most one of (x, y) and (y, x) may be … 展开

• The diagram is a schematic representation of the graph with vertices $${\displaystyle V=\{1,2,3,4,5,6\}}$$ and edges
• In computer science, directed graphs are used to represent knowledge (e.g., conceptual graph 展开

In a hypergraph, an edge can join any positive number of vertices.
An undirected graph can be seen as a simplicial complex consisting … 展开

Definitions in graph theory vary. The following are some of the more basic ways of defining graphs and related mathematical structures.
Graph
A graph (sometimes called an undirected graph to distinguish it … 展开

Two edges of a graph are called adjacent if they share a common vertex. Two edges of a directed graph are called consecutive if the head of the first one is the tail of the second one. Similarly, two vertices are called adjacent if they share a common edge (consecutive if the … 展开

There are several operations that produce new graphs from initial ones, which might be classified into the following categories:
• unary operations, which create a new graph from an initial one, … 展开