is_forest¶

is_forest(G)[source]¶

Returns \(True\) if G is a forest.

A forest is a graph with no undirected cycles.

For directed graphs, \(G\) is a forest if the underlying graph is a forest. The underlying graph is obtained by treating each directed edge as a single undirected edge in a multigraph.

Parameters :

G : graph

The graph to test.

Returns :

b : bool

A boolean that is \(True\) if \(G\) is a forest.