Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A $4$-choosable graph that is not $(8:2)$-choosable   In 1980, Erd\H{o}s, Rubin and Taylor asked whether for all positive integers
$a$, $b$, and $m$, every $(a:b)$-choosable graph is also $(am:bm)$-choosable.
We provide a negative answer by exhibiting a $4$-choosable graph that is not
$(8:2)$-choosable.

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The categories of this paper are: hep-ph
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The categories of this paper are: chao-dyn
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The categories of this paper are: atom-ph
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The categories of this paper are: plasm-ph
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The categories of this paper are: patt-sol
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The categories of this paper are: physics
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The categories of this paper are: adap-org
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The categories of this paper are: alg-geom
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The categories of this paper are: hep-ex
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The categories of this paper are: solv-int
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The categories of this paper are: gr-qc
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The categories of this paper are: cs
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The categories of this paper are: q-alg
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The categories of this paper are: eess
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The categories of this paper are: cond-mat
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The categories of this paper are: supr-con