Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: On Omega Context Free Languages which are Borel Sets of Infinite Rank   This paper is a continuation of the study of topological properties of omega
context free languages (omega-CFL). We proved before that the class of
omega-CFL exhausts the hierarchy of Borel sets of finite rank, and that there
exist some omega-CFL which are analytic but non Borel sets. We prove here that
there exist some omega context free languages which are Borel sets of infinite
(but not finite) rank, giving additional answer to questions of Lescow and
Thomas [Logical Specifications of Infinite Computations, In:"A Decade of
Concurrency", Springer LNCS 803 (1994), 583-621].

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The categories of this paper are: hep-ex
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The categories of this paper are: math-ph
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The categories of this paper are: hep-th
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The categories of this paper are: mtrl-th
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The categories of this paper are: q-fin
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The categories of this paper are: ao-sci
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The categories of this paper are: quant-ph
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The categories of this paper are: chao-dyn
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The categories of this paper are: comp-gas
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The categories of this paper are: cmp-lg
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The categories of this paper are: nucl-ex
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The categories of this paper are: plasm-ph
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The categories of this paper are: dg-ga
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The categories of this paper are: supr-con
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The categories of this paper are: eess
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The categories of this paper are: atom-ph