Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Sink-Stable Sets of Digraphs   We introduce the notion of sink-stable sets of a digraph and prove a min-max
formula for the maximum cardinality of the union of k sink-stable sets. The
results imply a recent min-max theorem of Abeledo and Atkinson on the Clar
number of bipartite plane graphs and a sharpening of Minty's coloring theorem.
We also exhibit a link to min-max results of Bessy and Thomasse and of Sebo on
cyclic stable sets.

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The categories of this paper are: acc-phys
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The categories of this paper are: atom-ph
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The categories of this paper are: patt-sol
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The categories of this paper are: funct-an
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The categories of this paper are: eess
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The categories of this paper are: comp-gas
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The categories of this paper are: cond-mat
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The categories of this paper are: nucl-th
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The categories of this paper are: econ
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The categories of this paper are: q-alg
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The categories of this paper are: chao-dyn
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The categories of this paper are: nlin
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The categories of this paper are: q-fin
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The categories of this paper are: nucl-ex
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The categories of this paper are: math-ph
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The categories of this paper are: hep-lat