DCG
2000
14 years 6 months ago
2000
In this paper we consider the cocircuit graph GM of an oriented matroid M, the 1-skeleton of the cell complex W formed by the span of the cocircuits of M. In general, W is not dete...
JCT
2006
14 years 6 months ago
2006
The cocircuit graph of an oriented matroid is the 1-skeleton of the cellular decomposition induced by the Topological Representation Theorem due to Folkman and Lawrence (1978) [J....
EJC
2006
14 years 6 months ago
2006
We present a seemingly new definition of flows and flow numbers for oriented matroids and prove that the flow number L and the antisymmetric flow number Las of an oriented matroid...
EJC
2006
14 years 6 months ago
2006
We study the positive Bergman complex B+ (M) of an oriented matroid M, which is a certain subcomplex of the Bergman complex B(M) of the underlying unoriented matroid M. The positiv...