Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Finite element approximation of an incompressible chemically reacting
  non-Newtonian fluid
23
The categories of this paper are: solv-int
31
The categories of this paper are: ao-sci
5
The categories of this paper are: gr-qc
28
The categories of this paper are: alg-geom
17
The categories of this paper are: q-fin
32
The categories of this paper are: atom-ph
27
The categories of this paper are: comp-gas
7
The categories of this paper are: hep-th
12
The categories of this paper are: nucl-th
33
The categories of this paper are: plasm-ph
35
The categories of this paper are: mtrl-th
9
The categories of this paper are: nlin
16
The categories of this paper are: stat
15
The categories of this paper are: nucl-ex
30
The categories of this paper are: q-alg
10
The categories of this paper are: q-bio