Implication graph

Implication Graph (IG) is a directed graph G(V, E) comprising vertex set V and directed edge set E. Each vertex in V represent the true or the false status of a boolean literal and each directed edge e(u, v) connecting vertex u and vertex v represents the implication "If the literal u is true then the literal v is also true". IGs were originally used identifying if a Boolean expression is satisfiable or not.