The total graph 
of a graph 
has a graph vertex for each
graph edge and graph vertex
of 
and a graph
edge in 
for every edge-edge,
vertex-edge, and vertex-vertex adjacency
in 
(Harary and Palmer 1973, p. 264;
Capobianco and Molluzzo 1978; Skiena 1990, p. 162).
In other words, the total graph 
of a graph 
is a graph such that the vertex
set of 
corresponds to the vertices and edges
of 
and two vertices
are adjacent in 
iff their corresponding elements are
either adjacent or incident
in 
.
Total graphs are generalizations of line graphs.
