isForest -- determines whether a graph is a forest

• Usage:

  f = isForest G

• Inputs:
  • G, a graph,
• Outputs:
  • f, a Boolean value, whether a graph is a forest

i1 : G = graph({{1,2},{1,3},{6,4},{4,5}},EntryMode=>"edges");

i2 : isForest G

o2 = true