Abstract
A digraph H is immersed in a digraph G if the vertices of H are mapped to (distinct) vertices of G, and the edges of H are mapped to directed paths joining the corresponding pairs of vertices of G, in such a way that the paths are pairwise edge-disjoint. For graphs the same relation (using paths instead of directed paths) is a well-quasi-order; that is, in every infinite set of graphs some one of them is immersed in some other. The same is not true for digraphs in general; but we show it is true for tournaments (a tournament is a directed complete graph).
Original language | English (US) |
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Pages (from-to) | 47-53 |
Number of pages | 7 |
Journal | Journal of Combinatorial Theory. Series B |
Volume | 101 |
Issue number | 1 |
DOIs | |
State | Published - Jan 2011 |
All Science Journal Classification (ASJC) codes
- Theoretical Computer Science
- Discrete Mathematics and Combinatorics
- Computational Theory and Mathematics
Keywords
- Digraph
- Immersion
- Minor
- Tournament
- Well-quasi-order