Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Further results on monoids acting on trees   This paper further develops the theory of arbitrary semigroups acting on
trees via elliptic mappings. A key tool is the Lyndon-Chiswell length function
L for the semigroup S which allows one to construct a tree T and an action of S
on T via elliptic maps. Improving on previous results, the length function of
the action will also be L.

14
The categories of this paper are: math-ph
17
The categories of this paper are: q-fin
37
The categories of this paper are: supr-con
7
The categories of this paper are: hep-th
10
The categories of this paper are: q-bio
22
The categories of this paper are: chao-dyn
16
The categories of this paper are: stat
30
The categories of this paper are: q-alg
0
The categories of this paper are: hep-ph
5
The categories of this paper are: gr-qc
12
The categories of this paper are: nucl-th
6
The categories of this paper are: astro-ph
28
The categories of this paper are: alg-geom
9
The categories of this paper are: nlin
21
The categories of this paper are: adap-org
33
The categories of this paper are: plasm-ph