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611
The Temporal Query Language TQuel
 ACM Transactions on Database Systems
, 1987
"... This paper defines aggregates in the temporal query language TQuel and provides their rormal semantics in the tuple relational calculus. A rormal semantics (or Que! aggregates is defined in the process. Multiple aggregates; aggregates appearing in the where, when, valid, and asor clauses; nested ag ..."
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Cited by 332 (45 self)
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This paper defines aggregates in the temporal query language TQuel and provides their rormal semantics in the tuple relational calculus. A rormal semantics (or Que! aggregates is defined in the process. Multiple aggregates; aggregates appearing in the where, when, valid, and asor clauses; nested
fo
"... acce e 2 as v as am he terms of physical properties, phase types and phase proportions that were predicted by models from literature. Foaming, as represented as well as converter systems where oxygen or air is injected on foaming in slags with high FexO concentrations were considered, firstly with t ..."
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with the aim of providing additional fundamental measurements and relationships, and secondly to Eq. (1) defines the foam index as it is most commonly used values previously reported for metallurgical slags of different compositions, ranging from 0.3 to 56 s (Roth et al.,
Regular tree languages definable in FO and FOmod
 In Proc. STACS’05, volume 3404 of Springer LNCS
, 2005
"... We consider regular languages of labeled trees. We give an effective characterization of the regular languages over such trees that are definable in firstorder logic in the language of labeled graphs. These languages are the analog on trees of the “locally threshold testable ” languages on strings. ..."
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Cited by 10 (4 self)
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We consider regular languages of labeled trees. We give an effective characterization of the regular languages over such trees that are definable in firstorder logic in the language of labeled graphs. These languages are the analog on trees of the “locally threshold testable ” languages on strings
ON LOGICAL HIERARCHIES WITHIN FO2DEFINABLE LANGUAGES
"... Abstract. We consider the class of languages defined in the 2variable fragment of the firstorder logic of the linear order. Many interesting characterizations of this class are known, as well as the fact that restricting the number of quantifier alternations yields an infinite hierarchy whose le ..."
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Cited by 6 (5 self)
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Abstract. We consider the class of languages defined in the 2variable fragment of the firstorder logic of the linear order. Many interesting characterizations of this class are known, as well as the fact that restricting the number of quantifier alternations yields an infinite hierarchy whose
DynFO: A Parallel, Dynamic Complexity Class
 Journal of Computer and System Sciences
, 1994
"... Traditionally, computational complexity has considered only static problems. Classical Complexity Classes such as NC, P, and NP are defined in terms of the complexity of checking  upon presentation of an entire input  whether the input satisfies a certain property. For many applications of compu ..."
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Cited by 53 (4 self)
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Traditionally, computational complexity has considered only static problems. Classical Complexity Classes such as NC, P, and NP are defined in terms of the complexity of checking  upon presentation of an entire input  whether the input satisfies a certain property. For many applications
NonDefinability Results for Randomised FirstOrder Logic
"... We investigate the expressive power of randomised firstorder logic (BPFO) on restricted classes of structures. While BPFO is stronger than FO in general, even on structures with a builtin addition relation, we show that BPFO is not stronger than FO on structures with a unary vocabulary, nor on the ..."
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on the class of equivalence relations. The same techniques can be applied to show that evenness of a linear order, and therefore graph connectivity, can not be defined in BPFO. Finally, we show that there is an FO[≤]definable query on word structures which can not be defined in BPFO[+1].
Deciding definability in FO2(< h, <v) on trees
"... We prove that it is decidable whether a regular unranked tree language is definable in FO2(< h,<v). By FO2(< h,<v) we refer to the two variable fragment of first order logic built from the descendant and following sibling predicates. In terms of expressive power it corresponds to a fragm ..."
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We prove that it is decidable whether a regular unranked tree language is definable in FO2(< h,<v). By FO2(< h,<v) we refer to the two variable fragment of first order logic built from the descendant and following sibling predicates. In terms of expressive power it corresponds to a
The FO² alternation hierarchy is decidable
, 2012
"... We consider the twovariable fragment FO²[<] of firstorder logic over finite words. Numerous characterizations of this class are known. Thérien and Wilke have shown that it is decidable whether a given regular language is definable in FO²[<]. From a practical point of view, as shown by Weis, ..."
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We consider the twovariable fragment FO²[<] of firstorder logic over finite words. Numerous characterizations of this class are known. Thérien and Wilke have shown that it is decidable whether a given regular language is definable in FO²[<]. From a practical point of view, as shown by Weis
Dynamic Definability
, 2012
"... We investigate the logical resources required to maintain knowledge about a property of a finite structure that undergoes an ongoing series of local changes such as insertion or deletion of tuples to basic relations. Our framework is closely related to the DynFOframework of Patnaik and Immerman an ..."
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Cited by 4 (0 self)
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We investigate the logical resources required to maintain knowledge about a property of a finite structure that undergoes an ongoing series of local changes such as insertion or deletion of tuples to basic relations. Our framework is closely related to the DynFOframework of Patnaik and Immerman
Results 1  10
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611