Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Representation Theory of the Algebra Generated By a Pair of Complex
  Structures   The objective of this paper is to determine the finite dimensional,
indecomposable representations of the algebra that is generated by two complex
structures over the real numbers. Since the generators satisfy relations that
are similar to those of the infinite dihedral group, we give the algebra the
name iD-infinity.

14
The categories of this paper are: math-ph
16
The categories of this paper are: stat
24
The categories of this paper are: dg-ga
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The categories of this paper are: bayes-an
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The categories of this paper are: mtrl-th
5
The categories of this paper are: gr-qc
3
The categories of this paper are: physics
21
The categories of this paper are: adap-org
12
The categories of this paper are: nucl-th
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The categories of this paper are: patt-sol
6
The categories of this paper are: astro-ph
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The categories of this paper are: alg-geom
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The categories of this paper are: eess
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The categories of this paper are: acc-phys
22
The categories of this paper are: chao-dyn
29
The categories of this paper are: funct-an