The problem of enriching logic programming with set constructs has deserved an increasing attention in recent years. Indeed the availability of set abstractions is widely recognized as a valuable feature of high-level programming languages. And logic programming languages seem to be right candidates for hosting such a feature due to their potentially high declarative nature.

Most of the attention to enriching logic programming with sets has come from the field of deductive databases; however, many other fields, including rapid software prototyping and knowledge based systems, may benefit from the availability of set constructs. Also, interesting theoretical issues as well as implementation ones are involved in the definition of such an extension.

This workshop is intended to provide a first opportunity to exchange ideas on the many possible ways the problem can be coped with and to discuss the potentiality of logic programming with sets. The following issues, in particular, are expected to be addressed:

• which kind of objects one should aim at dealing with: extensional, intensional, multi-, hyper- sets;
• what operations on sets should the language provide as primitives; - what is the term representation of sets;
• what is the role of negation and set grouping in intensional set definition;
• which is the host language: pure Horn clause, constraint l.p., equational logic language;
• what kind of applications may benefit more from such an extension;
• in particular, what is the potential impact of set-formers on deductive databases;
• what are the main issues in developing efficient implementations.

Also set-oriented programming in other programming paradigms (e.g. functional, rule-based, ...) can be considered as a good theme for discussion in the workshop.

On the basis of recent publications on this subject, about 20-25 persons are estimated to be interested in attending the workshop. The participants who wish to give a talk should submit an abstract of their proposed contribution by April 1, 1993 to

Gianfranco ROSSI
Dipartimento di Matematica Universita' di Bologna
Porta di P.zza S.Donato, 5
40127 BOLOGNA - ITALY
Telephone: + 39 - 51 - 354496
Fax: +39 - 51 - 354490
email: gianfr@dm.unibo.it

Abstracts should not exceed two pages in length. Submissions by e-mail using LaTex format are also welcome. Notification of acceptance will be mailed (possibly via e-mail) by May 1. The extended version of accepted abstracts to appear in the workshop notes will be due by May 15.

Organizing Committee:

Eugenio Omodeo, University of Rome
Gianfranco Rossi, University of Bologna