Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Affine Homogeneous Surfaces with Hessian rank 2 and Algebras of
  Differential Invariants
4
The categories of this paper are: cond-mat
34
The categories of this paper are: chem-ph
11
The categories of this paper are: hep-lat
18
The categories of this paper are: econ
37
The categories of this paper are: supr-con
9
The categories of this paper are: nlin
8
The categories of this paper are: hep-ex
22
The categories of this paper are: chao-dyn
0
The categories of this paper are: hep-ph
35
The categories of this paper are: mtrl-th
23
The categories of this paper are: solv-int
10
The categories of this paper are: q-bio
12
The categories of this paper are: nucl-th
27
The categories of this paper are: comp-gas
24
The categories of this paper are: dg-ga
30
The categories of this paper are: q-alg