xml_tree::node_t y = tags->select_next(xml_tree::ATTRIBUTE_OPEN_TAG_ID, x);
while (y != xml_tree::NIL && y < fin){
size -= subtree_size(y);
xml_tree::node_t y = tags->select_next(xml_tree::ATTRIBUTE_OPEN_TAG_ID, x);
while (y != xml_tree::NIL && y < fin){
size -= subtree_size(y);