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Coalgebraic modal logic beyond Sets
 In MFPS XXIII
, 2007
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Cited by 10 (3 self)
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Replace this file with prentcsmacro.sty for your meeting, or with entcsmacro.sty for your meeting. Both can be
A model of database components and their interconnection based upon communicating views
 in: Hannu Jakkola, Yashui Kiyoki, and Takehiro Tokuda, eds., Information Modelling and Knowledge Systems XXIV, Frontiers in Artificial Intelligence and Applications, IOS Press, 2007, In
"... Abstract A formalism for constructing database schemata from simple components is presented in which the components are coupled to one another via communicating views. The emphasis is upon identifying the conditions under which such components can be interconnected in a conflictfree fashion, and a ..."
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Cited by 7 (5 self)
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Abstract A formalism for constructing database schemata from simple components is presented in which the components are coupled to one another via communicating views. The emphasis is upon identifying the conditions under which such components can be interconnected in a conflictfree fashion, and a characterization of such, based upon the acyclicity of an underlying hypergraph, is obtained. The work is furthermore oriented towards an understanding of how updates can be supported within the componentbased framework, and initial ideas of socalled canonical liftings are presented. 1.
The relative complexity of updates for a class of database views
 Foundations of Information and Knowledge Systems: Third International Symposium, FoIKS 2004, Wilehminenberg
, 2004
"... Abstract. It is well known that the complexity of testing the correctness of an arbitrary update to a database view can be far greater than the complexity of testing a corresponding update to the main schema. However, views are generally managed according to some protocol which limits the admissible ..."
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Abstract. It is well known that the complexity of testing the correctness of an arbitrary update to a database view can be far greater than the complexity of testing a corresponding update to the main schema. However, views are generally managed according to some protocol which limits the admissible updates to a subset of all possible changes. The question thus arises as to whether there is a more tractable relationship between these two complexities in the presence of such a protocol. In this paper, this question is answered in the affirmative for closed update strategies, which are based upon the constantcomplement approach of Bancilhon and Spyratos. Working within a very general framework which is independent of any particular data model, but which recaptures relational schemata constrained by socalled equalitygenerating dependencies (EGDs), (which include functional dependencies (FDs)), it is shown that the complexity of testing the correctness of a view update which follows a closed update strategy is no greater than that of testing a corresponding update to the main schema. In particular, if the main schema is relational and constrained by FDs, then there exists a set of FDs on the view, against which any candidate update may be tested for correctness. This holds even though the entire view may not be finitely axiomatizable, much less constrained by FDs alone. 1
Characterization of type hierarchies with open specification
 in Semantics in Databases: Second International Workshop, Dagstuhl
"... Abstract. Type hierarchies which arise in applications are often described incompletely; this missing information may be handled in a variety of ways. In this work, such incomplete hierarchies are viewed as open specifications; that is, descriptions which are sets of constraints. The actual hierarch ..."
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Cited by 2 (1 self)
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Abstract. Type hierarchies which arise in applications are often described incompletely; this missing information may be handled in a variety of ways. In this work, such incomplete hierarchies are viewed as open specifications; that is, descriptions which are sets of constraints. The actual hierarchy is then any structure satisfying these constraints. For such specifications, two forms of characterization are provided. The first is algebraic and utilizes a generalization of weak partial lattices; it provides a structurebased characterization in which optimality is characterized via an initial construction. The second is logical, an inferencebased representation, in which models are characterized as products of models of propositionalbased specifications. 1.
Proof of the Decidability of the Uniform Word Problem for Monads Assisted by Elf
, 1994
"... . We present a full proof of a canonical system for adjunctions as already suggested in [Cur93]. Termination can be shown in a similar style to [HL86]. Confluence is shown by checking all critical pairs. This is done firstly in the Larch Prover [GG91] and secondly more correctly in the programming l ..."
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Cited by 2 (1 self)
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. We present a full proof of a canonical system for adjunctions as already suggested in [Cur93]. Termination can be shown in a similar style to [HL86]. Confluence is shown by checking all critical pairs. This is done firstly in the Larch Prover [GG91] and secondly more correctly in the programming language Elf [Pfe89]. Exploiting theorems from category theory [BW85] this system can be used to solve the uniform word problem for monads. The resulting decision procedure is finally implemented in Elf. 1 Introduction A general problem in category theory is to check the commutativity of certain diagrams where diagrams are nothing but a compact encoding and visualization of equations involving morphisms. In [FS90] one can even find a suitable graphical language. Checking the commutativity means to check the equality of morphisms in a given category. To support this process one can solve the uniform word problem for this category which is of course not always possible having the halting probl...
CATEGORICAL DATASPECIFICATIONS
, 1995
"... We introduce MDsketches, which are a particular kind of Finite Sum sketches. Two interesting results about MDsketches are proved. First, we show that, given two MDsketches, it is algorithmically decidable whether their model categories are equivalent. Next we show that dataspecifications, as use ..."
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Cited by 1 (0 self)
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We introduce MDsketches, which are a particular kind of Finite Sum sketches. Two interesting results about MDsketches are proved. First, we show that, given two MDsketches, it is algorithmically decidable whether their model categories are equivalent. Next we show that dataspecifications, as used in databasedesign and software engineering, can be translated to MDsketches. As a corollary, we obtain that equivalence of dataspecifications is decidable.
AModel of Database Components and their Interconnection Based uponCommunicating Views
"... Abstract Aformalism forconstructing database schematafromsimplecomponents is presented in which the components are coupled to one another via communicating views. The emphasis is upon identifying the conditions under which such components can be interconnected in a conflictfree fashion, and a chara ..."
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Abstract Aformalism forconstructing database schematafromsimplecomponents is presented in which the components are coupled to one another via communicating views. The emphasis is upon identifying the conditions under which such components can be interconnected in a conflictfree fashion, and a characterization of such, based upon the acyclicity of an underlying hypergraph, is obtained. The work is furthermore oriented towards an understanding of how updates can be supported within the componentbased framework, and initial ideas of socalled canonical liftings are presented. 1.
A Flexible Semantic Framework for Effects
"... Effects are a powerful and convenient component of programming. They enable programmers to interact with the user, take advantage of efficient stateful memory, throw exceptions, and nondeterministically execute programs in parallel. However, they also complicate every aspect of reasoning about a pro ..."
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Effects are a powerful and convenient component of programming. They enable programmers to interact with the user, take advantage of efficient stateful memory, throw exceptions, and nondeterministically execute programs in parallel. However, they also complicate every aspect of reasoning about a program or language, and as a result it is crucially important to have a good understanding of what effects are and how they work. In this paper we present a new framework for formalizing the semantics of effects that is more general and thorough than previous techniques while clarifying many of the important concepts. By returning to the categorytheoretic roots of monads, our framework is rich enough to describe the semantics of effects for a large class of languages including common imperative and functional languages. It is also capable of capturing more expressive, precise, and practical effect systems than previous approaches. Finally, our framework enables one to reason about effects in a languageindependent manner, and so can be applied to many stages of language design and implementation in order to create more broadly applicable tools for programming languages. 1.
Bialgebraic Operational Semantics and Modal Logic (extended abstract)
"... A novel, general approach is proposed to proving the compositionality of process equivalences on languages defined by Structural Operational Semantics (SOS). The approach, based on modal logic, is inspired by the simple observation that if the set of formulas satisfied by a process can be derived fr ..."
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A novel, general approach is proposed to proving the compositionality of process equivalences on languages defined by Structural Operational Semantics (SOS). The approach, based on modal logic, is inspired by the simple observation that if the set of formulas satisfied by a process can be derived from the corresponding sets for its subprocesses, then the logical equivalence is a congruence. Striving for generality, SOS rules are modeled categorically as bialgebraic distributive laws for some notions of process syntax and behaviour, and modal logics are modeled via coalgebraic polyadic modal logic. Compositionality is proved by providing a suitable notion of behaviour for the logic together with a dual distributive law, reflecting the one modeling the SOS specification. Concretely, the dual laws may appear as SOSlike rules where logical formulas play the role of processes, and their behaviour models logical decomposition over process syntax. The approach can be used either to proving compositionality for specific languages or for defining SOS congruence formats.