Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Galois theory, graphs and free groups   A self-contained exposition is given of the topological and Galois-theoretic
properties of the category of combinatorial 1-complexes, or graphs, very much
in the spirit of Stallings. A number of classical, as well as some new results
about free groups are derived.

19
The categories of this paper are: eess
21
The categories of this paper are: adap-org
10
The categories of this paper are: q-bio
17
The categories of this paper are: q-fin
7
The categories of this paper are: hep-th
28
The categories of this paper are: alg-geom
37
The categories of this paper are: supr-con
25
The categories of this paper are: patt-sol
0
The categories of this paper are: hep-ph
22
The categories of this paper are: chao-dyn
29
The categories of this paper are: funct-an
26
The categories of this paper are: bayes-an
15
The categories of this paper are: nucl-ex
32
The categories of this paper are: atom-ph
34
The categories of this paper are: chem-ph
11
The categories of this paper are: hep-lat