Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The isomorphism relation for separable C*-algebras   We prove that the isomorphism relation for separable C$^*$-algebras, and also
the relations of complete and $n$-isometry for operator spaces and systems, are
Borel reducible to the orbit equivalence relation of a Polish group action on a
standard Borel space.

15
The categories of this paper are: nucl-ex
37
The categories of this paper are: supr-con
21
The categories of this paper are: adap-org
28
The categories of this paper are: alg-geom
23
The categories of this paper are: solv-int
18
The categories of this paper are: econ
8
The categories of this paper are: hep-ex
20
The categories of this paper are: acc-phys
32
The categories of this paper are: atom-ph
12
The categories of this paper are: nucl-th
4
The categories of this paper are: cond-mat
7
The categories of this paper are: hep-th
11
The categories of this paper are: hep-lat
17
The categories of this paper are: q-fin
1
The categories of this paper are: cs
16
The categories of this paper are: stat