Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A remarkable family of left ordered groups: central extensions of Hecke
  groups   We provide an infinite family of left-ordered groups, all of which have a
positive cone that is finitely generated as a semigroup. This family includes
the Klein bottle group and the braid group B_3.

27
The categories of this paper are: comp-gas
24
The categories of this paper are: dg-ga
22
The categories of this paper are: chao-dyn
14
The categories of this paper are: math-ph
9
The categories of this paper are: nlin
31
The categories of this paper are: ao-sci
28
The categories of this paper are: alg-geom
26
The categories of this paper are: bayes-an
13
The categories of this paper are: quant-ph
16
The categories of this paper are: stat
18
The categories of this paper are: econ
21
The categories of this paper are: adap-org
33
The categories of this paper are: plasm-ph
25
The categories of this paper are: patt-sol
29
The categories of this paper are: funct-an
20
The categories of this paper are: acc-phys