Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Two Bijections for Dyck Path Parameters   Here we give two bijections, one to show that the number of UUU-free Dyck
n-paths is the Motzkin number M_n, the other to obtain the (known)
distributions of the parameters "number of UDUs" and "number of DDUs" on Dyck
n-paths. The first bijection is straightforward, the second not quite so
obvious.

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The categories of this paper are: alg-geom
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The categories of this paper are: adap-org
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The categories of this paper are: q-fin
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The categories of this paper are: atom-ph
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The categories of this paper are: funct-an
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The categories of this paper are: nucl-ex
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The categories of this paper are: hep-ph
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The categories of this paper are: chem-ph
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The categories of this paper are: comp-gas
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The categories of this paper are: hep-th
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The categories of this paper are: cmp-lg
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The categories of this paper are: patt-sol
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The categories of this paper are: hep-lat
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The categories of this paper are: quant-ph
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The categories of this paper are: physics
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The categories of this paper are: bayes-an