Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A characterization of triangulations of closed surfaces   In this paper we prove that a finite triangulation of a connected closed
surface is completely determined by its intersection matrix. The
\emph{intersection matrix} of a finite triangulation, $K$, is defined as
$M_{K}=(dim(s_{i}\cap s_{j}))_{0\leq i,0\leq j}^{n-1}$, where $K_{2}=\{s_{0},
\ldots s_{n-1}\}$ is a labelling of the triangles of $K$.

10
The categories of this paper are: q-bio
6
The categories of this paper are: astro-ph
18
The categories of this paper are: econ
12
The categories of this paper are: nucl-th
25
The categories of this paper are: patt-sol
28
The categories of this paper are: alg-geom
5
The categories of this paper are: gr-qc
4
The categories of this paper are: cond-mat
34
The categories of this paper are: chem-ph
17
The categories of this paper are: q-fin
30
The categories of this paper are: q-alg
36
The categories of this paper are: cmp-lg
29
The categories of this paper are: funct-an
16
The categories of this paper are: stat
35
The categories of this paper are: mtrl-th
1
The categories of this paper are: cs