Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The complete classification for quantified equality constraints   We prove that QCSP$(\mathbb{N};x=y\rightarrow y=z)$ is PSpace-complete,
settling a question open for more than ten years. This completes the complexity
classification for quantified equality languages as a trichotomy between
Logspace, NP-complete and PSpace-complete.

20
The categories of this paper are: acc-phys
34
The categories of this paper are: chem-ph
23
The categories of this paper are: solv-int
30
The categories of this paper are: q-alg
4
The categories of this paper are: cond-mat
32
The categories of this paper are: atom-ph
25
The categories of this paper are: patt-sol
19
The categories of this paper are: eess
36
The categories of this paper are: cmp-lg
12
The categories of this paper are: nucl-th
8
The categories of this paper are: hep-ex
28
The categories of this paper are: alg-geom
29
The categories of this paper are: funct-an
17
The categories of this paper are: q-fin
18
The categories of this paper are: econ
21
The categories of this paper are: adap-org