=== GraphViz Export ===
Avalog supports exporting to the GraphViz format for visualization.

  graph               expands all facts and exports data
  graphf "<file>"     sets output file
  no graphf           uses ".dot" after last imported file,
                      or "tmp.dot" if there is no imported file
  graphl "<layout>"   sets layout GraphViz algorithm

List of layout algorithm:

  dot         hierarchial directed graphs
  neato       spring model using energy
  fdp         spring model using forces
  sfdp        multiscale fdp
  twopi       concentric circles
  circo       circo