These graphs must be read in the following way: All the possible edges in between v vertices are labeled as 1,2,.... There are v over 2 possible edges. A graph is interpreted to be a function f mapping the set of all edges into the set {1,2}. These functions are written as

[f(1),f(2),...].

f(i)=1 means the edge with number i occurs in the graph.

f(i)=2 means the edge with number i does not occur in the graph.