Dynamics of Higher Spin Fields and Tensorial Space

The structure and the dynamics of massless higher spin fields in various dimensions are reviewed with an emphasis on conformally invariant higher spin fields. We show that in D=3,4,6 and 10 dimensional space-time the conformal higher spin fields constitute the quantum spectrum of a twistor-like particle propagating in tensorial spaces of corresponding dimensions. We give a detailed analysis of the field equations of the model and establish their relation with known formulations of free higher spin field theory.Comment: JHEP3 style, 40 pages; v2 typos corrected, comments and references added; v3 published versio

Abstract interpretation for (constraint) logic programming

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Using call/exit analysis for logic program transformation

© Springer-Verlag Berlin Heidelberg 1994. A technique for transformation of definite logic programs is presented. A first phase performs an analysis of the extended call/exit patterns of the source program. It is shown that a particular form of correct abstract call/exit patterns can be used as a guide to control the transformation itself and can help to generate the target program having desired properties. The technique provides a framework which, combined with problem specific information concerning the source program, can lead to nontrivial transformations.status: publishe

Abstract interpretation for (constraint) logic programming

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Deriving transformations of logic programs using abstract interpretation

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Index-driven semantics of logic programs

An operational semantics is presented. It is aimed at developing a wide class of static analysis frameworks. Each computed answer of a program is assigned an index, with encodes SLD-derivations with this computed answer. This is concisely formalised as a reachable $epsilon$-algebra with the constraint s-model as its domain. This puts together the top-down SLD-resolution and the non-ground bottom-up computation giving rise to a novel approach for computing opeational properties with surjective $epsilon$-homomorphisms as an abstraction. An approximation is a finite homomorphic image of the concrete algebra.status: publishe

Deriving fold unfold transformations of logic programs using extended oldt-based abstract interpretation

An extension of OLDT based abstract interpretation for definite logic programs is presented. The extension can abstract the behavior of programs under different computation rules. The abstract behavior is captured in an EOLDT structure. It is shown that this EOLDT structure can guide an automatic equivalence preserving fold/unfold transformation. By making the appropriate choices during the abstract interpretation phase, one can obtain EOLDT structures which lead to a very broad range of transformations. It is argued that the approach provides a unifying framework for a large class of transformations. © 1993, Academic Press Limited. All rights reserved.status: publishe

Using abstract interpretation for goal replacement

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