Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Automata for two-variable logic over trees with ordered data values   Data trees are trees in which each node, besides carrying a label from a
finite alphabet, also carries a data value from an infinite domain. They have
been used as an abstraction model for reasoning tasks on {XML} and
verification. However, most existing approaches consider the case where only
equality test can be performed on the data values.
  In this paper we study data trees in which the data values come from a
linearly ordered domain, and in addition to equality test, we can test whether
the data value in a node is greater than the one in another node. We introduce
an automata model for them which we call ordered-data tree automata (ODTA),
provide its logical characterisation, and prove that its non-emptiness problem
is decidable in 3-NEXPTIME. We also show that the two-variable logic on
unranked trees, studied by Bojanczyk, Muscholl, Schwentick and Segoufin in
2009, corresponds precisely to a special subclass of this automata model.
  Then we define a slightly weaker version of ODTA, which we call weak ODTA,
and provide its logical characterisation. The complexity of the non-emptiness
problem drops to NP. However, a number of existing formalisms and models
studied in the literature can be captured already by weak ODTA. We also show
that the definition of ODTA can be easily modified, to the case where the data
values come from a tree-like partially ordered domain, such as strings.

21
The categories of this paper are: adap-org
6
The categories of this paper are: astro-ph
15
The categories of this paper are: nucl-ex
20
The categories of this paper are: acc-phys
37
The categories of this paper are: supr-con
35
The categories of this paper are: mtrl-th
9
The categories of this paper are: nlin
27
The categories of this paper are: comp-gas
7
The categories of this paper are: hep-th
25
The categories of this paper are: patt-sol
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The categories of this paper are: alg-geom
0
The categories of this paper are: hep-ph
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The categories of this paper are: gr-qc
8
The categories of this paper are: hep-ex
26
The categories of this paper are: bayes-an
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The categories of this paper are: q-fin