Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: On limits of betweenness relations   We give a flexible method for constructing a wide variety of limits of
betweenness relations. This unifies work of Adeleke, who constructed a Jordan
group preserving a limit of betweenness relations, and Bhattacharjee and
Macpherson who gave an alternative method using a Fra\"ss\'e-type construction.
A key ingredient in their work is the notion of a tree of B-sets. We employ
this, and extend its use to a wider class of examples.

16
The categories of this paper are: stat
25
The categories of this paper are: patt-sol
13
The categories of this paper are: quant-ph
34
The categories of this paper are: chem-ph
24
The categories of this paper are: dg-ga
8
The categories of this paper are: hep-ex
37
The categories of this paper are: supr-con
9
The categories of this paper are: nlin
14
The categories of this paper are: math-ph
19
The categories of this paper are: eess
17
The categories of this paper are: q-fin
22
The categories of this paper are: chao-dyn
28
The categories of this paper are: alg-geom
26
The categories of this paper are: bayes-an
31
The categories of this paper are: ao-sci
36
The categories of this paper are: cmp-lg