Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A Supplement to the Classification of Flat Homogeneous Spaces of
  Signature (m,2)   Duncan and Ihrig (1993) gave a classification of the flat homogeneous spaces
of metric signature (m,2), provided that a certain condition on the development
image of these spaces holds. In this note we show that this condition can be
dropped, so that Duncan and Ihrig's classification is in fact the full
classification for signature (m,2).

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The categories of this paper are: quant-ph
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The categories of this paper are: cond-mat
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The categories of this paper are: nucl-ex
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The categories of this paper are: gr-qc
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The categories of this paper are: acc-phys
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The categories of this paper are: dg-ga
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The categories of this paper are: patt-sol
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The categories of this paper are: comp-gas
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The categories of this paper are: hep-lat
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The categories of this paper are: cs
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The categories of this paper are: nucl-th
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The categories of this paper are: adap-org
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The categories of this paper are: astro-ph
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The categories of this paper are: econ
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The categories of this paper are: q-alg
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The categories of this paper are: plasm-ph