Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: On the direct evidence of time-reversal non-invariance in the $K^0-\bar
  K^0$ system   The measurements of the CP violation parameters by the CPLEAR experiment are
reviewed. It is shown that attempts to prove T-violation from the semileptonic
asymmetries are flawed by logical inconsistencies.

13
The categories of this paper are: quant-ph
12
The categories of this paper are: nucl-th
37
The categories of this paper are: supr-con
29
The categories of this paper are: funct-an
8
The categories of this paper are: hep-ex
22
The categories of this paper are: chao-dyn
28
The categories of this paper are: alg-geom
21
The categories of this paper are: adap-org
7
The categories of this paper are: hep-th
1
The categories of this paper are: cs
23
The categories of this paper are: solv-int
25
The categories of this paper are: patt-sol
6
The categories of this paper are: astro-ph
9
The categories of this paper are: nlin
26
The categories of this paper are: bayes-an
32
The categories of this paper are: atom-ph