COMBINATORICA
2007
13 years 11 months ago
2007
The main result of this paper is that every 4-uniform hypergraph on n vertices and m edges has a transversal with no more than (5n + 4m)/21 vertices. In the particular case n = m,...
DM
2006
13 years 11 months ago
2006
In this paper it is shown that every m
DCG
2008
13 years 11 months ago
2008
We prove Helly-type theorems for line transversals to disjoint unit balls in Rd . In particular, we show that a family of n 2d disjoint unit balls in Rd has a line transversal if,...