Question in title. Looking for whether there is a term that is, if not widely understood, at least citeable to a source.
This is equivalent to asking for the set of nodes that are comparable to the given node in the preorder induced by the digraph. But that's as much of a mouthful as what I wrote in the title.
Example: Consider the following digraph.
Given the above graph and the node y, I am looking for a term that refers to the set {u, v, w, y, z} but excludes x, because x is neither upstream nor downstream of y.
