Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: On the completeness of a family of functions in mathematical fluid
  dynamics
31
The categories of this paper are: ao-sci
14
The categories of this paper are: math-ph
5
The categories of this paper are: gr-qc
32
The categories of this paper are: atom-ph
1
The categories of this paper are: cs
37
The categories of this paper are: supr-con
34
The categories of this paper are: chem-ph
36
The categories of this paper are: cmp-lg
6
The categories of this paper are: astro-ph
30
The categories of this paper are: q-alg
23
The categories of this paper are: solv-int
27
The categories of this paper are: comp-gas
7
The categories of this paper are: hep-th
2
The categories of this paper are: math
8
The categories of this paper are: hep-ex
9
The categories of this paper are: nlin