determine if there is a path between two vertices
IsReachable(G, u, v)
vertices of the graph
IsReachable(G, u, v) returns a true when the vertex v is reachable from u in the graph G.
To produce an actual path (or directed path when G is directed) from u to v, use BellmanFordAlgorithm, DijkstrasAlgorithm, or ShortestPath.
To find all vertices reachable from u, use Reachable.
If G is an undirected graph, a vertex w is said to be reachable from a vertex v if there exists a path in G between v and w. This is true if and only if they are in the same connected component.
If G is a directed graph, a vertex w is said to be reachable from a vertex v if there exists a directed path in G from v to w.
C6 ≔ CycleGraph⁡6
C6≔Graph 1: an undirected graph with 6 vertices and 6 edge(s)
With the following example we see that the reachability relation is not symmetric for directed graphs.
DP4 ≔ Graph⁡A,B,C,D,A,B,B,C,C,D
DP4≔Graph 2: a directed graph with 4 vertices and 3 arc(s)
The GraphTheory[IsReachable] command was introduced in Maple 2018.
For more information on Maple 2018 changes, see Updates in Maple 2018.
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