DM
2006
13 years 11 months ago
2006
For a set X of vertices of a graph fulfilling local connectedness conditions the existence of a cycle containing X is proved. AMS classification: 05C38, 05C45, 05C35
DM
2006
13 years 11 months ago
2006
DM
2006
13 years 11 months ago
2006
Abstract. We present some simple observations on factors of the qbinomial coefficients, the q-Catalan numbers, and the q-multinomial coefficients. Writing the Gaussian coefficient ...
DM
2006
13 years 11 months ago
2006
DM
2006
13 years 11 months ago
2006
Let (x, y) be a bivariate polynomial with complex coefficients. The zeroes of (x, y) are given a combinatorial structure by considering them as arcs of a directed graph G(). This p...
DM
2006
13 years 11 months ago
2006
DM
2006
13 years 11 months ago
2006
Our main result describes how to extend a matroid so that its ground set is a modular hyperplane of the larger matroid. This result yields a new way to view Dowling lattices and ne...
DM
2006
13 years 11 months ago
2006
DM
2006
13 years 11 months ago
2006
For a chordal graph G = (V, E), we study the problem of whether a new vertex u V and a given set of edges between u and vertices in V can be added to G so that the resulting grap...
DM
2006
13 years 11 months ago
2006