Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Verifying Heaps' law using Google Books Ngram data   This article is devoted to the verification of the empirical Heaps law in
European languages using Google Books Ngram corpus data. The connection between
word distribution frequency and expected dependence of individual word number
on text size is analysed in terms of a simple probability model of text
generation. It is shown that the Heaps exponent varies significantly within
characteristic time intervals of 60-100 years.

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The categories of this paper are: cond-mat
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The categories of this paper are: mtrl-th
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The categories of this paper are: math-ph
32
The categories of this paper are: atom-ph
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The categories of this paper are: supr-con
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The categories of this paper are: hep-th
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The categories of this paper are: patt-sol
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The categories of this paper are: q-bio
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The categories of this paper are: nucl-ex
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The categories of this paper are: comp-gas
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The categories of this paper are: chem-ph
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The categories of this paper are: adap-org
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The categories of this paper are: q-alg
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The categories of this paper are: quant-ph
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The categories of this paper are: acc-phys
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The categories of this paper are: hep-ph