Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Problems on automorphism groups of nonpositively curved polyhedral
  complexes and their lattices   The goal of this paper is to present a number of problems about automorphism
groups of nonpositively curved polyhedral complexes and their lattices, meant
to highlight possible directions for future research.

33
The categories of this paper are: plasm-ph
19
The categories of this paper are: eess
18
The categories of this paper are: econ
21
The categories of this paper are: adap-org
36
The categories of this paper are: cmp-lg
34
The categories of this paper are: chem-ph
30
The categories of this paper are: q-alg
35
The categories of this paper are: mtrl-th
23
The categories of this paper are: solv-int
37
The categories of this paper are: supr-con
1
The categories of this paper are: cs
7
The categories of this paper are: hep-th
10
The categories of this paper are: q-bio
6
The categories of this paper are: astro-ph
25
The categories of this paper are: patt-sol
26
The categories of this paper are: bayes-an