Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Level rings arising from meet-distributive meet-semilattices   The Alexander dual of an arbitrary meet-semilattice is described explicitly.
Meet-distributive meet-semilattices whose Alexander dual is level are
characterized.

4
The categories of this paper are: cond-mat
5
The categories of this paper are: gr-qc
22
The categories of this paper are: chao-dyn
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The categories of this paper are: quant-ph
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The categories of this paper are: adap-org
37
The categories of this paper are: supr-con
15
The categories of this paper are: nucl-ex
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The categories of this paper are: hep-lat
31
The categories of this paper are: ao-sci
12
The categories of this paper are: nucl-th
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The categories of this paper are: stat
0
The categories of this paper are: hep-ph
33
The categories of this paper are: plasm-ph
23
The categories of this paper are: solv-int
32
The categories of this paper are: atom-ph
1
The categories of this paper are: cs