Lin Hsin Hsin Unified Theory of Graph

Definition

Directed Acyclic Graph, DAG is a finite directed graph with no directed cycles, it has a finite number of vertices (nodes) and edges (paths), whereby every edge directs from one vertiex to the other, follows a consistently-directed sequence of edges that does not loop back to the start node

Graphs are ubiquitous, they can be used to model directed or undirected connectivities in the real world.

A set of vertices {v1, v2, ..vn}
and a set of edges {e1, e2, ..em}

An edge is defined as a pair of connected vertices
{vi, vj}, where i,j ∈ {1,...n}