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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 – A boolean that is True if G is a forest.
Return type:bool


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

See also