Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The amalgamated duplication of a ring along a multiplicative-canonical
  ideal   After recalling briefly the main properties of the amalgamated duplication of
a ring $R$ along an ideal $I$, denoted by $R\JoinI$, we restrict our attention
to the study of the properties of $R\JoinI$, when $I$ is a multiplicative
canonical ideal of $R$ \cite{hhp}. In particular, we study when every regular
fractional ideal of $R\Join I$ is divisorial.

13
The categories of this paper are: quant-ph
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The categories of this paper are: eess
14
The categories of this paper are: math-ph
0
The categories of this paper are: hep-ph
22
The categories of this paper are: chao-dyn
27
The categories of this paper are: comp-gas
26
The categories of this paper are: bayes-an
18
The categories of this paper are: econ
36
The categories of this paper are: cmp-lg
28
The categories of this paper are: alg-geom
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The categories of this paper are: supr-con
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The categories of this paper are: nucl-th
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The categories of this paper are: patt-sol
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The categories of this paper are: funct-an
5
The categories of this paper are: gr-qc
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The categories of this paper are: q-bio