The forbidden minor characterization of line-search antimatroids of rooted digraphs
نویسندگان
چکیده
منابع مشابه
The forbidden minor characterization of line-search antimatroids of rooted digraphs
An antimatroid is an accessible union-closed family of subsets of a 0nite set. A number of classes of antimatroids are closed under taking minors such as point-search antimatroids of rooted (di)graphs, line-search antimatroids of rooted (di)graphs, shelling antimatroids of rooted trees, shelling antimatroids of posets, etc. The forbidden minor characterizations are known for point-search antima...
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چکیده ندارد.
15 صفحه اولColoring digraphs with forbidden cycles
Let k and r be two integers with k ≥ 2 and k ≥ r ≥ 1. In this paper we show that (1) if a strongly connected digraph D contains no directed cycle of length 1 modulo k, then D is k-colorable; and (2) if a digraph D contains no directed cycle of length r modulo k, then D can be vertex-colored with k colors so that each color class induces an acyclic subdigraph in D. The first result gives an affi...
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ژورنال
عنوان ژورنال: Discrete Applied Mathematics
سال: 2003
ISSN: 0166-218X
DOI: 10.1016/s0166-218x(02)00471-7