def is_frond(u, v, dfs_data):
d_u = D(u, dfs_data)<EOL>d_v = D(v, dfs_data)<EOL>edge_id = dfs_data['<STR_LIT>'].get_first_edge_id_by_node_ids(u, v)<EOL>return True if dfs_data['<STR_LIT>'][edge_id] == '<STR_LIT>' and d_v < d_u else False<EOL>
Determines if the edge uv is a frond ("backedge").