claim: Cultists worship Cthulhu.
evidence: In graph theory , a clique graph of an undirected graph G is another graph K -LRB- G -RRB- that represents the structure of cliques in G.. graph theory. graph theory. undirected graph. undirected graph. Clique graphs were discussed at least as early as 1968 , and a characterization of clique graphs was given in 1971 .