Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Positroids are 3-colorable   We show that every positroid of rank $r \geq 3$ has a positive coline. Using
the definition of the chromatic number of oriented matroid introduced by J.\
Ne\v{s}et\v{r}il, R.\ Nickel, and W.~Hochst\"{a}ttler, this shows that every
orientation of a positroid is 3-colorable.

3
The categories of this paper are: physics
5
The categories of this paper are: gr-qc
33
The categories of this paper are: plasm-ph
9
The categories of this paper are: nlin
6
The categories of this paper are: astro-ph
14
The categories of this paper are: math-ph
26
The categories of this paper are: bayes-an
7
The categories of this paper are: hep-th
24
The categories of this paper are: dg-ga
21
The categories of this paper are: adap-org
32
The categories of this paper are: atom-ph
4
The categories of this paper are: cond-mat
22
The categories of this paper are: chao-dyn
34
The categories of this paper are: chem-ph
1
The categories of this paper are: cs
12
The categories of this paper are: nucl-th