Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Differential-difference system related to toroidal Lie algebra   We present a novel differential-difference system in (2+1)-dimensional
space-time (one discrete, two continuum), arisen from the Bogoyavlensky's
(2+1)-dimensional KdV hierarchy. Our method is based on the bilinear identity
of the hierarchy, which is related to the vertex operator representation of the
toroidal Lie algebra $\sl_2^{tor}$.

34
The categories of this paper are: chem-ph
11
The categories of this paper are: hep-lat
8
The categories of this paper are: hep-ex
31
The categories of this paper are: ao-sci
32
The categories of this paper are: atom-ph
1
The categories of this paper are: cs
21
The categories of this paper are: adap-org
3
The categories of this paper are: physics
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The categories of this paper are: solv-int
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The categories of this paper are: econ
5
The categories of this paper are: gr-qc
13
The categories of this paper are: quant-ph
30
The categories of this paper are: q-alg
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The categories of this paper are: eess
35
The categories of this paper are: mtrl-th
26
The categories of this paper are: bayes-an