The functions to get minimum spanning trees make use of two algorithms:

Algorithm		Application
Prim		for dense graphs with many edges
Kruskal		for sparse graphs with few edges

The following functions are implemented to get spanning trees:

Function		Short Description
MinimumSpanningTree		spanning tree with minimum cost
AnySpanningTree		spanning tree
AnyDirectedSpanningTree		directed spanning tree

The facing column contains an example for MinimumSpanningTree.