/* Remove peninsulas - chains hanging off the main graph */
BEGIN {
edge_t e;
node_t v, n;
}
N [degree == 1] {
n = $;
while (n.degree == 1) {
e = fstedge (n);
if (e.head == n) v = e.tail;
else v = e.head;
delete($G,n);
n = v;
}
}