An Example of Clifford Algebras Calculations with GiNaC

This example of Clifford algebras calculations uses GiNaC (http://www.ginac.de/) library, which includes a support for generic Clifford algebra starting from version~1.3.0. Both symbolic and numeric calculation are possible and can be blended with other functions of GiNaC. This calculations was made for the paper math.CV/0410399. Described features of GiNaC are already available at PyGiNaC (http://sourceforge.net/projects/pyginac/) and due to course should propagate into other software like GNU Octave (http://www.octave.org/), gTybalt (http://www.fis.unipr.it/~stefanw/gtybalt.html), which use GiNaC library as their back-end.Comment: 20 pages, LaTeX2e, 12 PS graphics in one figure; v3 code improvements; v4 small code correction for new libraries; v5 comments are redesined to be more readabl

Requirements for software engineering languages

This paper analyzes the concepts of software construction embodied in the Draco system. The analysis relates specific mechanisms in Draco to particular software engineering (SE) principles and suggests future research needed to extend the approach. The purpose of the analysis is to help researchers understand Draco better and thus be able to direct in productive directions future research on this type of software engineering tool

Octonionic Mobius Transformations

A vexing problem involving nonassociativity is resolved, allowing a generalization of the usual complex Mobius transformations to the octonions. This is accomplished by relating the octonionic Mobius transformations to the Lorentz group in 10 spacetime dimensions. The result will be of particular interest to physicists working with lightlike objects in 10 dimensions.Comment: Plain TeX, 12 pages, 1 PostScript figure included using eps

Bidirectional Model Transformations in QVT: Semantic Issues and Open Questions

(QVT) standard as applied to the specification of bidirectional transformations between models. We discuss what is meant by bidirectional transformations, and the model-driven development scenarios in which they are needed. We analyse the fundamental requirements on tools which support such transformations, and discuss some semantic issues which arise. We argue that a considerable amount of basic research is needed before suitable tools will be fully realisable, and suggest directions for this future research