Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Exponential bases on multi-rectangles in $\mathbb{R}^d$   We construct explicit exponential bases on finite unions of disjoint
rectangles of $\mathbb{R}^d$ with rational vertices.

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The categories of this paper are: hep-ph
22
The categories of this paper are: chao-dyn
32
The categories of this paper are: atom-ph
18
The categories of this paper are: econ
30
The categories of this paper are: q-alg
29
The categories of this paper are: funct-an
37
The categories of this paper are: supr-con
19
The categories of this paper are: eess
1
The categories of this paper are: cs
34
The categories of this paper are: chem-ph
16
The categories of this paper are: stat
28
The categories of this paper are: alg-geom
27
The categories of this paper are: comp-gas
4
The categories of this paper are: cond-mat
8
The categories of this paper are: hep-ex
24
The categories of this paper are: dg-ga