c A graph representing a Boolean circuit.
p edge N E
n v c
e v1 v2
The graph file format itself does not make any distinction between
undirected and directed graphs;
this is done by a tool that uses the file format
(e.g. the command bliss graphfile
vs. bliss -directed graphfile
).
When the graph file is interpreted as an undirected graph,
a line "e v1 v2
" represents the undirected edge
between the vertices v1 and v2,
and is thus equivalent to the line "e v2 v1
".
For directed graphs,
a line "e v1 v2
" represents the directed edge from
the vertex v1 to the vertex v2.
c An example graph. p edge 4 5 n 2 1 e 1 2 e 4 1 e 2 3 e 2 4 e 3 4When interpreted as a directed graph, the same description represents the directed graph: