Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Groupoids in combinatorics -- applications of a theory of local
  symmetries   An objective of the theory of combinatorial groupoids is to introduce
concepts like "holonomy", "parallel transport", "bundles", "combinatorial
curvature" etc. in the context of simplicial (polyhedral) complexes, posets,
graphs, polytopes, arrangements and other combinatorial objects. In this paper
we give an exposition of some of the currently most active research themes in
this area, offer a unified point of view, and provide a list of prospective
applications in other fields together with a collection of related open
problems.

34
The categories of this paper are: chem-ph
4
The categories of this paper are: cond-mat
21
The categories of this paper are: adap-org
17
The categories of this paper are: q-fin
20
The categories of this paper are: acc-phys
22
The categories of this paper are: chao-dyn
29
The categories of this paper are: funct-an
36
The categories of this paper are: cmp-lg
23
The categories of this paper are: solv-int
24
The categories of this paper are: dg-ga
15
The categories of this paper are: nucl-ex
18
The categories of this paper are: econ
35
The categories of this paper are: mtrl-th
37
The categories of this paper are: supr-con
13
The categories of this paper are: quant-ph
6
The categories of this paper are: astro-ph