ELA, Volume 9, pp. 1-20, February 2002, abstract.
The P_0-matrix completion problem
Ji Young Choi, Luz Maria DeAlba, Leslie Hogben,
Mandi S. Maxwell, and Amy Wangsness
In this paper the P_0-matrix completion problem is
considered. It is established that every asymmetric
partial P_0-matrix has P_0-completion. All 4-by-4
patterns that include all diagonal positions are
classified as either having P_0-completion or not
having P_0-completion. It is shown that any
positionally symmetric pattern whose graph is an
n-cycle, with n greater than or equal to 5, has
P_0-completion.