Let {a, b, c} be a triangle in a 3-connected matroid M. In this paper, we describe the structure of M relative to {a, b, c} when, for all t in {a, b, c}, either M\t is not 3-connec...
Given an undirected hypergraph and a subset of vertices S V with a specified root vertex r S, the STEINER ROOTED-ORIENTATION problem is to find an orientation of all the hypered...
We exhibit a a counterexample to a conjecture of Thomassen stating that the number of distinct 3-colorings of every graph whose 3color matrix has full column rank is superpolynomi...