Un week-end d'initiation-formation est organisé les 6 et 7 juillet. Il est gracieusement hebergé par la conférence ISSAC. Il est destiné à toute personne utilisant (ou simplement intéressée) par le calcul formel (par exemple pour l'enseignement), qui voudrait en apprendre davantage sur la façon dont fonctionnent les systèmes de calcul formel. Ce week-end est en Français et quasiment gratuit.

Pour en savoir davantage, téléchargez la "lettre aux collègues" contenant le formulaire d'inscription (date limite : le 10 juin) et l'annonce, tous deux en mode texte.

**Lettre** :
PostScript,
pdf et
texte.

**Annonce** :
PostScript,
pdf et
texte.

9h00-18h00 Thursday July 11, 2002

Maison d'Activités Culturelles et de Colloques (MACC)

University of Lille I, Lille, France.

The most successful current programming languages are based the paradigm of object orientation, where individual data objects have state which is modified by object-specific methods. These programming languages do not lend themselves to the natural expression of mathematical algorithms, which view computation more as a calculation of new values from multiple given objects, which are left unchanged.

A number of independent programming languages have emerged which offer a more natural setting for mathematical algorithms, and which arguably have all of the benefits of object orientation. The common trait of these languages is to treat types as values and to make pervasive use of dependent types. Examples include Pebble (to explore type theory), NuPrl and COQ (for computer assisted theorem proving), and Aldor (for computer algebra). Each of these provides a realization of a typed higher-order lambda calculus in which the usual object oriented paradigm can be recovered through the use of dependent product types.

Of these languages, Aldor is of particular interest for the area of algorithmic mathematics because its type system is designed to support rich hierarchies of type categories corresponding to the categories of modern algebra.

Such "Categorical Programming Languages" allow the natural expression of algorithms in the most generic setting. Generalization algorithms takes the form of weakening categorical constraints on arguments, or strengthening categorical statements about their return values. Far from being "abstract nonsense," this approach leads to highly configurable software with sufficient information to compile efficient code.

For more information about Aldor, please visit the official website (www.aldor.org).

Workshop participants shall fall into four groups:

- those who have been central in the establishing the ideas in categorical programming languages for computer algebra,
- those who have used categorical programming languages in industrial and other non-university settings
- university researchers and students who might wish to use Aldor in courses or research projects.
- researchers and students who might wish to contribute to Aldor

Ms Bethany Heinrichs bethany@scl.csd.uwo.ca

and should include:

Name:

Affiliation:

Special dietary requirements:

Previous use of Aldor, if any:

Do you wish to make a presentation:

- the University of Lille I,
- the University of Western Ontario,
- the Ontario Research Center for Computer Algebra

For technical remarks, contact webmaster : lemaire@lifl.fr

Last modified on Fri Jul 5 11:46:51 MET DST 2002