This is the function that a processor can call with a path, and returns all the processors that own nodes below that node in the structure. This can then allow a processor to drop out of a part or of the computation if it owns none of the nodes in that sub section. It works much the same as the processor mapping algorithm.
![\begin{figure}
\begin{verbatim}
Range r = [1, n]
i = first direction in p
while(...
... i, currdegree)
i -\gt next direction in p
}
return r\end{verbatim}\end{figure}](img42.gif)