t>G1</tt>) of the global edge
<tt>(C,F)</tt> (or numerically <tt>(2,5)</tt>).  Adding an edge to a
subgraph causes the edge to also be added to all of its ancestors in
the subgraph tree to ensure that the subgraph property is maintained.

<pre>
add_edge(A1, C1, G1); // (A1,C1) is subgraph G1 local indices
                      // for the global edge (C,F).
</pre>

<!----------------------------->
<h3>Where Defined</h3>

<tt>boost/graph/subgraph.hpp</tt>

<!----------------------------->
<h3>Template Paramet