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is_forest

is_forest(G)

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.

See also

is_branching

Notes

In another convention, a directed forest is known as a polyforest and then forest corresponds to a branching.