Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Basic Subtoposes of the Effective Topos   We employ a new tool (sights) to investigate local operators in the Effective
Topos. A number of new such local operators is analyzed using this machinery.
Moreover, we investigate a local operator defined in the thesis of A. Pitts,
and establish that its corresponding subtopos satisfies true arithmetic.

26
The categories of this paper are: bayes-an
5
The categories of this paper are: gr-qc
12
The categories of this paper are: nucl-th
15
The categories of this paper are: nucl-ex
1
The categories of this paper are: cs
24
The categories of this paper are: dg-ga
30
The categories of this paper are: q-alg
28
The categories of this paper are: alg-geom
14
The categories of this paper are: math-ph
18
The categories of this paper are: econ
16
The categories of this paper are: stat
17
The categories of this paper are: q-fin
3
The categories of this paper are: physics
7
The categories of this paper are: hep-th
22
The categories of this paper are: chao-dyn
10
The categories of this paper are: q-bio