Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: On the Nonlocal Equations and Nonlocal Charges Associated with the Harry
  Dym Hierarchy   A large class of nonlocal equations and nonlocal charges for the Harry Dym
hierarchy is exhibited. They are obtained from nonlocal Casimirs associated
with its bi-Hamiltonian structure. The Lax representation for some of these
equations is also given.

6
The categories of this paper are: astro-ph
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The categories of this paper are: nucl-th
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The categories of this paper are: dg-ga
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The categories of this paper are: eess
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The categories of this paper are: q-bio
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The categories of this paper are: comp-gas
2
The categories of this paper are: math
36
The categories of this paper are: cmp-lg
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The categories of this paper are: solv-int
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The categories of this paper are: adap-org
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The categories of this paper are: quant-ph
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The categories of this paper are: stat
0
The categories of this paper are: hep-ph
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The categories of this paper are: mtrl-th
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The categories of this paper are: bayes-an
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The categories of this paper are: econ