“…For the hardness of deciding equality in (5), we describe the efficient construction of a graph H such that f is satisfiable if and only if diss(H) = α(H). For every clause C i = x ∨ y ∨ z in f , where x, y, and z are the three literals in C i , we introduce the six vertices x (i,1) , y (i,1) , z (i,1) , x (i,2) , y (i,2) , and z (i,2) in H that induce a subgraph H i that is a clique minus the three edges 1) x (i,2) , y (i,1) y (i,2) , and z (i,1) z (i,2) . Similarly as above, the vertices x (i,1) , y (i,1) , and z (i,1) in H i are associated with the three literals x, y, and z in C i .…”