Intermediate node as a root node for dominator tree

Can dominator trees be built with an intermediate node as the root node? ( Assuming that I am ignoring all the previous nodes in the original dominator tree while making 开发者_如何转开发this new tree? )

Thanks in advance.

The "dominance" property is defined in terms of all possible paths from the start node to a given node.

If you want to build a tree, rooted at some intermediate node N, you will have to devise another notion of "dominance", for example, node D dominates node S, if all possible paths from N to S pass trough D.

The problem here is that such a tree may not even exist, if there's no path from N to S.