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Proceedings First International Workshop on Rewriting Techniques for Real-Time Systems  [PDF]
Peter Csaba ?lveczky
Computer Science , 2010, DOI: 10.4204/EPTCS.36
Abstract: This volume contains the proceedings of the First International Workshop on Rewriting Techniques for Real-Time Systems (RTRTS 2010), held in Longyearbyen, Spitsbergen, on April 6-9, 2010. The aim of the workshop is to bring together researchers with an interest in the use of rewriting-based techniques (including rewriting logic) and tools for the modeling, analysis, and/or implementation of real-time and hybrid systems, and to give them the opportunity to present their recent works, discuss future research directions, and exchange ideas. The topics of the workshop comprise, but are not limited to: methods and tools supporting rewriting-based modeling and analysis of real-time and hybrid systems, and extensions of such systems; use of rewriting techniques to provide rigorous support for model-based software engineering of timed systems; applications and case studies; and comparison with other formalisms and tools.
Relations between three formalisms for irrotational binary neutron stars in general relativity  [PDF]
Eric Gourgoulhon
Physics , 1998,
Abstract: Various formalisms proposed recently for irrotational binary systems in general relativity are compared and explicit relations between them are exhibited. It is notably shown that the formalisms of (i) Teukolsky, (ii) Shibata and (iii) Bonazzola et al. (as corrected by Asada) are equivalent, i.e. yield exactly the same solution, although the former two are simpler than the latter one.
Correspondence between Jordan-Einstein frames and Palatini-metric formalisms  [PDF]
Salvatore Capozziello,Farhad Darabi,Daniele Vernieri
Physics , 2010, DOI: 10.1142/S0217732310034456
Abstract: We discuss the conformal symmetry between Jordan and Einstein frames considering their relations with the metric and Palatini formalisms for modified gravity. Appropriate conformal transformations are taken into account leading to the evident connection between the gravitational actions in the two mentioned frames and the Hilbert-Einstein action with a cosmological constant. We show that the apparent differences between Palatini and metric formalisms strictly depend on the representation while the number of degrees of freedom is preserved. This means that the dynamical content of both formalism is identical.
Rewriting Logic Semantics of a Plan Execution Language
Gilles Dowek,César Mu?oz,Camilo Rocha
Electronic Proceedings in Theoretical Computer Science , 2010, DOI: 10.4204/eptcs.18.6
Abstract: The Plan Execution Interchange Language (PLEXIL) is a synchronous language developed by NASA to support autonomous spacecraft operations. In this paper, we propose a rewriting logic semantics of PLEXIL in Maude, a high-performance logical engine. The rewriting logic semantics is by itself a formal interpreter of the language and can be used as a semantic benchmark for the implementation of PLEXIL executives. The implementation in Maude has the additional benefit of making available to PLEXIL designers and developers all the formal analysis and verification tools provided by Maude. The formalization of the PLEXIL semantics in rewriting logic poses an interesting challenge due to the synchronous nature of the language and the prioritized rules defining its semantics. To overcome this difficulty, we propose a general procedure for simulating synchronous set relations in rewriting logic that is sound and, for deterministic relations, complete. We also report on two issues at the design level of the original PLEXIL semantics that were identified with the help of the executable specification in Maude.
Query Rewriting and Optimization for Ontological Databases  [PDF]
Georg Gottlob,Giorgio Orsi,Andreas Pieris
Computer Science , 2014,
Abstract: Ontological queries are evaluated against a knowledge base consisting of an extensional database and an ontology (i.e., a set of logical assertions and constraints which derive new intensional knowledge from the extensional database), rather than directly on the extensional database. The evaluation and optimization of such queries is an intriguing new problem for database research. In this paper, we discuss two important aspects of this problem: query rewriting and query optimization. Query rewriting consists of the compilation of an ontological query into an equivalent first-order query against the underlying extensional database. We present a novel query rewriting algorithm for rather general types of ontological constraints which is well-suited for practical implementations. In particular, we show how a conjunctive query against a knowledge base, expressed using linear and sticky existential rules, that is, members of the recently introduced Datalog+/- family of ontology languages, can be compiled into a union of conjunctive queries (UCQ) against the underlying database. Ontological query optimization, in this context, attempts to improve this rewriting process so to produce possibly small and cost-effective UCQ rewritings for an input query.
A Comparison of Paraconsistent Description Logics  [PDF]
Norihiro Kamide
International Journal of Intelligence Science (IJIS) , 2013, DOI: 10.4236/ijis.2013.32011

Description logics (DLs) are a family of logic-based knowledge representation formalisms with a number of computer science applications. DLs are especially well-known to be valuable for obtaining logical foundations of web ontology languages (e.g., W3C’s ontology language OWL). Paraconsistent (or inconsistency-tolerant) description logics (PDLs) have been studied to cope with inconsistencies which may frequently occur in an open world. In this paper, a comparison and survey of PDLs is presented. It is shown that four existing paraconsistent semantics (i.e., four-valued semantics, quasi-classical semantics, single-interpretation semantics and dual-interpretation semantics) for PDLs are essentially the same semantics. To show this, two generalized and extended new semantics are introduced, and an equivalence between them is proved.

The Rewriting of a Literary Work – Between Esthetics and Ideology  [PDF]
Studii de Stiinta si Cultura , 2013,
Abstract: This study analyses the causes and effects of rewriting a literary work from the ideological and esthetical perspectives. The Spider's Web is published in 1938, and after the setting-up of the communist regime, its author, CellaSerghi, wishing to see her novel being published again, decides to make successive changes of her literary work for the editions from 1946, 1962 and 1971. Beyond the writer's constant preocupation for the polishing of expression , which is reflected from one edition to the next one, these changes of the content of her novel, eliminate, replace or add "certain" meanings, ment to make the book more desirable for the communist censorship.
Operator Mapping between RNS and Extended Pure Spinor Formalisms for Superstring  [PDF]
Yuri Aisaka,Yoichi Kazama
Physics , 2003, DOI: 10.1088/1126-6708/2003/08/047
Abstract: An explicit operator mapping in the form of a similarity transformation is constructed between the RNS formalism and an extension of the pure spinor formalism (to be called EPS formalism) recently proposed by the present authors. Due to the enlarged field space of the EPS formalism, where the pure spinor constraints are removed, the mapping is completely well-defined in contrast to the one given previously by Berkovits in the original pure spinor (PS) formalism. This map provides a direct demonstration of the equivalence of the cohomologies of the RNS and the EPS formalisms and is expected to be useful for better understanding of various properties of the PS and EPS formalisms. Furthermore, the method of construction, which makes systematic use of the nilpotency of the BRST charges, should find a variety of applications.
A general proof of the equivalence between the δN and covariant formalisms  [PDF]
Atsushi Naruko
Physics , 2012, DOI: 10.1209/0295-5075/98/69001
Abstract: Recently, the equivalence between the \delta N and covariant formalisms has been shown (Suyama et al. 2012), but they essentially assumed Einstein gravity in their proof. They showed that the evolution equation of the curvature covector in the covariant formalism on uniform energy density slicings coincides with that of the curvature perturbation in the \delta N formalism assuming the coincidence of uniform energy and uniform expansion (Hubble) slicings, which is the case on superhorizon scales in Einstein gravity. In this short note, we explicitly show the equivalence between the \delta N and covariant formalisms without specifying the slicing condition and the associated slicing coincidence, in other words, regardless of the gravity theory.
ACD Term Rewriting  [PDF]
Gregory J. Duck,Peter J. Stuckey,Sebastian Brand
Computer Science , 2006,
Abstract: We introduce Associative Commutative Distributive Term Rewriting (ACDTR), a rewriting language for rewriting logical formulae. ACDTR extends AC term rewriting by adding distribution of conjunction over other operators. Conjunction is vital for expressive term rewriting systems since it allows us to require that multiple conditions hold for a term rewriting rule to be used. ACDTR uses the notion of a "conjunctive context", which is the conjunction of constraints that must hold in the context of a term, to enable the programmer to write very expressive and targeted rewriting rules. ACDTR can be seen as a general logic programming language that extends Constraint Handling Rules and AC term rewriting. In this paper we define the semantics of ACDTR and describe our prototype implementation.
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