Abstract
Let G be a tree and let ℋ be a collection of subgraphs of G, each having at most d connected components. Let v(ℋ) denote the maximum number of members of ℋ no two of which share a common vertex, and let τ(ℋ) denote the minimum cardinality of a set of vertices of G that intersects all members of ℋ. It is shown that τ(ℋ) ≤ 2d2v(ℋ). A similar, more general result is proved replacing the assumption that G is a tree by the assumption that it has a bounded tree-width. These improve and extend results of various researchers.
Original language | English |
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Pages (from-to) | 249-254 |
Number of pages | 6 |
Journal | Discrete Mathematics |
Volume | 257 |
Issue number | 2-3 |
DOIs | |
State | Published - 28 Nov 2002 |
Event | Kleitman and Combinatorics: A Celebration - Cambridge, MA, United States Duration: 16 Aug 1990 → 18 Aug 1990 |
Funding
Funders | Funder number |
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Hermann Minkowski Minerva Center for Geometry | |
Bloom's Syndrome Foundation | |
Israel Science Foundation | |
Tel Aviv University |