Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The palindromic width of a free product of groups   Palindromes are those reduced words of free products of groups that coincide
with their reverse words. We prove that a free product of groups $G$ has
infinite palindromic width, provided that $G$ is not the free product of two
cyclic groups of order two. This means that there is no a uniform bound $k$
such that every element of $G$ is a product of at most $k$ palindromes. Earlier
the similar fact established for non-abelian free groups.

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The categories of this paper are: q-bio
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The categories of this paper are: eess
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The categories of this paper are: econ
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The categories of this paper are: hep-th
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The categories of this paper are: q-alg
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The categories of this paper are: patt-sol
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The categories of this paper are: alg-geom
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The categories of this paper are: funct-an
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The categories of this paper are: quant-ph
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The categories of this paper are: hep-ex
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The categories of this paper are: comp-gas
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The categories of this paper are: dg-ga
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The categories of this paper are: gr-qc
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The categories of this paper are: nucl-ex
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The categories of this paper are: hep-lat
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The categories of this paper are: nucl-th