Deadlocks can be described precisely in terms of a directed graph called a wait-for graph. This graph consists of a pair G = (V, E), where V is a set of vertices and E isa set of edges. The set of vertices consists of all the transactions in the system. Eachelement in the set E of edges is an ordered pair Ti → Tj. If Ti → Tj is in E, then thereis a directed edge from transaction Ti to Tj , implying that transaction Ti is waitingfor transaction Tj to release a data item that it needs.