#!/usr/bin/perl

use Graph;

my $g = Graph->new;

$g->add_vertex( 'a' );             # Add one vertex at a time...
$g->add_vertex( 'b', 'c', 'd' );   # ...or several.

$g->add_edge( 'a', 'c' );       # One edge at a time...
$g->add_path( 'b', 'c', 'd' );  # ...or several edges.

print "g = $g\n";