How to set an id for node?

I need to set a unique Id for each node (to represent a BST that accept doubles ) , so I need to know how to use the id attribute.

[BST == binary search tree (??)]
I’m not sure if you really want id, label, or name, so:

  • the id attribute (id | Graphviz) is really aimed at post-processing - usually of SVG output file. An id does not show up visually (unless the post-processing causes it to show up)
  • the label attribute (label | Graphviz) does show up visually. multiple nodes can have the same label value
  • the name is not an attribute, but a unique identifier that can also be used as a label.
graph bst {
  a [id="one two" label="three"]         // name is a
  b [id="buckle shoe" label="three"]  // name is b
  splat [id="buggy"  label="gravity"]  // name is splat