Declarative specification and declarative programming

摘要

The preceding workshops of this series accompanied occurrencesof the International Conference on Software Engineering (ICSE).More precisely, the first workshop was held in Kyoto after ICSE-6(Tokyo, 1982), and the second one came with ICSE-7 (Orlando, 1984).IWSSD-3, IWSSD-4, and IWSSDJ followed respectively ICSE-8 in London(1985), ICSE-9 in Monterey (1987) and ICSE-11 in Pittsburgh(1989).>In 1988 a Steering Committee (chaired by Robert Babb) was formedto plan the fate of future IWSSD workshops. More precisely, thisCommittee is entrusted with the task of organizing the series andpreserving the spirit of the meetings, as well as their technicalquality. In particular, the Steering Committee chooses the time,the place and the chairpersons of the next workshop. A strongassociation with ICSE has had various advantages, but its recentlyadopted annual Jean-Pierre Finance schedule was considered toofrequent for the IWSSD series. The Steering Committee decided tomaintain a two-year periodicity,and consequently to associate theIWSSD workshops with several major conferences. Thus for the firsttime, this workshop follows the European Software EngineeringConference ESEC).>It is a great pleasure for me to welcome you today in thismarvellous site of the Centro di Cultura Scientifica "A. Volta" inComo. The purpose of this workshop, as its predecessors, is toexplore major trends and key issues in the specification and designof software systems. However, the spirit and the form differ fromthose of larger conferences on this topic by providing intensivediscussion in which formalists, methodologists, developers andpractitioners from both academia and industry can interact in aninformal, yet focused setting. Attendance is limited and is byinvitation on the basis of a submitted paper. The selection processhas two goals: to assess the authors' areas of interest and toprint those which are judged to be of most interest in the workshopproceedings. The 80 or so attendees will spend most of their timein oneof the small parallel working groups. The rest of the timewill be spent in plenary sessions.>Welcome to the Sixth International Workshop on SoftwareSpecification and Design, held in Como on 25-26 October, 1991.>As in the past, there has been a deliberate attempt to place theissues of specification and design within the general context ofsoftware engineering by maintaining a complementary link to a majorsoftware engineering conference. In 1991, this broader context isprovided by the Third European Software Engineering Conference,held in Milan, October 21-24, 1991.>Participation in the workshop continues to be limited to aselect number of researchers, chosen on the basis of a submittedpaper or position statement The total number of submissions thisyear was 111. Out of these, we decided to include in the workshop'sProceedings 22 regular papers and 10 position papers which werejudged to meet the high technical standards adopted by the 6IWSSDProgram Committee. The Proceedings, however, contain onlybackground material, most of which will be discussed during theworkshop. The workshop, in fact, is not organized around formalpaper presentations, but rather around focused discussions withinworking groups. This requires participants to take an active rolein raising problems, discussing possible solutions, identifyingopen issues, evaluating competing approaches, etc. On the basis ofaccepted submissions, the following sessions and associated workinggroups have been identified by the Program Committee:>- Requirements>- Concurrency and distribution>- Real-time systems>- Formal methods>- Design methods and process models>For each of these, two session coordinators have been nominated.In preparation for the workshop, they established a common set ofground rules designed to make discussions within each sessionhighly productive.>Judging from the quality of these Proceedings, we believe theIWSSD increasingly attracts top-level researchers who desire topresent their results to this forum. The papers published herereport on timely and novel results that can become the startingpoint for many stimulating discussions. Some clear trends inresearch in software specification and design are also evident inthese pages: the growing interest in formal methods and theirapplication to new and challenging aspects of concurrent anddistributed systems, real-time systems, software developmentprocesses, and structurally complex problems in general. Anotherrelated issue is the interplay between formal and informalreasoning.>In closing, we would like to thank all those who contributed toshaping the final program of the workshop: the members of theProgram Committee, for their careful reviews and their suggestions;the session coordinators, for their efforts in organizing theindividual sessions; and the authors of submitted papers, for theirintellectual contributions which helped us assemble a high-qualityprogram.