Structural Models: An Introduction to the Theory of Directed Graphs

acyclic digraph adjacency matrix assignment balanced basic block called chapter Clearly closed communication complete concept condition connectedness consider consists construct contains converse Corollary corresponding cost cycle cyclic D₁ definition digraph D digraph of Figure directional discussion distance distinct empirical entry equal equivalent exactly example flow given gives Hence illustrate Implies indegree indicate integer joining kinds least length matrix maximum means number of lines obtained origin outdegree pair of points path person point basis positive possible presented proof properties prove reach reachable receiver relation removal represent result S₁ satisfies score semicycle semipath semipath joining sequence shown in Figure signed digraph statement strictly strong component strong digraph structure subgraph subset symmetric Theorem theory tournament transitive transmitter triples unilateral unique v₁ v₂ weak component weak digraph