In graph theory, a clique is often a complete subset of a
graph. A maximal clique is a clique which can not be
enlarged. In statistics (and that is the convention we follow
here) a clique is usually understood to be a maximal clique.
Finding the cliques of a general graph is an NP complete problem. Finding
the cliques of triangualted graph is linear in the number of cliques.
The workhorse is the max_cliqueMAT function which calls the
maxClique function in the RBGL package.