digraph G {
  rankdir="LR"
  "set_units" [shape=ellipse style=filled fillcolor=cyan]
  "read_celllib early (modify)" [shape=ellipse style=filled fillcolor=cyan]
  "read_celllib late (modify)" [shape=ellipse style=filled fillcolor=cyan]
  "read_verilog" [shape=ellipse style=filled fillcolor=cyan]
  "read_spef (modify)" [shape=ellipse style=filled fillcolor=cyan]
  "set_units" -> "read_celllib early (modify)"
  "read_celllib early (parse)" -> "read_celllib early (modify)";
  "read_celllib late (modify)" -> "read_verilog"
  "read_celllib late (parse)" -> "read_celllib late (modify)"
  "read_celllib early (modify)" -> "read_celllib late (modify)"
  "read_spef (parse)" -> "read_spef (modify)";
  "read_verilog" -> "read_spef (modify)"
}