7012937
Integrating Lists, Multisets, and Sets in a Logic Programming Framework
The first order theories of lists, bags, compact-lists (i.e., lists where the number of contiguous occurrences of each element is immaterial), and sets are introduced via axioms. Such axiomatizations are shown to be especially suitable for the integration with free functor symbols governed by the classical Clark’s axioms in the context of Constraint Logic Programming. Adaptations of the extensionality principle to the various theories taken into account is then exploited in the design of unification algorithms for the considered data structures. All the theories presented can be combined providing frameworks to deal with several of the proposed data structures simoultaneously. The unification algorithms proposed can be combined (merged) as well to produce engines for such combination theories.
12466079
ACI1 constraints
Disuniication is the problem of deciding satissability of a system of equations and disequations w.r.t. a given equational theory. In this paper we study the disuni-cation problem in the context of ACI1 equational theories. We provide a characterization of the interpretation structures suitable to model the axioms in ACI1 theories. The satissability problem is solved using known techniques for the equality constraints and novel methodologies to transform disequation constraints into solved forms. We propose three solved forms, ooering an increasingly more precise characterization of the set of solutions. Two of them can be computed and tested in polynomial time. The novel results achieved open new possibilities in the practical and eecient manipulation of ACI1 constraints.
3157847
Intensional Sets in CLP
We propose a parametric introduction of intensionally defined sets into any \(CLP(\mathcal \{D\})\) language. The result is a language \(CLP({\mathcal \{D\}})\), where constraints over sets of elements of \(\mathcal D\) and over sets of sets of elements, and so on, can be expressed. The semantics of \(CLP({\mathcal \{D\}})\) is based on the semantics of logic programs with aggregates and the semantics of CLP over sets. We investigate the problem of constraint resolution in \(CLP({\mathcal \{D\}})\) and propose algorithms for constraints simplification.
15589668
Logic Meta-Programming Facilities in 'LOG
A meta-level extension of a logic programming language is presented. The resulting language, called 'LOG (read quote-log), provides meta-programming facilities similar to those of Prolog while preserving a declarative logical semantics. It also offers new meta-programming opportunities as compared with Prolog due to its ability to treat whole programs, i.e. sequences of clauses, as data objects. The extension basically consists in defining a suitable naming scheme. It associates two different but related meta-representations with every syntactic object of the language, from characters to programs. The choice of the double metarepresentation is motivated by both the user and the implementation viewpoints. All Prolog built-in meta-predicates can be redefined as 'LOG programs by exploiting the new naming scheme. Then some syntactic sugar is added to make the language more concrete. Some examples are given, in particular to show the ability of the language to deal with programs as data.
23168836
JSetL: a Java library for supporting declarative programming in Java
60140
A uniform approach to constraint-solving for lists, multisets, compact lists, and sets
Lists, multisets, and sets are well-known data structures whose usefulness is widely recognized in various areas of computer science. They have been analyzed from an axiomatic point of view with a parametric approach in Dovier et al. [1998], where the relevant unification algorithms have been developed. In this article, we extend these results considering more general constraints, namely, equality and membership constraints and their negative counterparts.
38243163
Querying Hypermedia Applications in an Object-Oriented Framework
1956133
Enhancing a requirements baseline with scenarios
Scenarios are well recognised as an important strategy towards understanding the interface between the environment and the system as well as a means of eliciting and specifying software behaviour. We adopt a broader view of scenarios. For us, a scenario is an evolving description of situations in the environment. Our proposal is framed by Leite’s work on a client-oriented requirements baseline, which aims to model the external requirements of a software system and its evolution. Scenarios start by describing the environment situations, according to the main actions performed outside the software system. Scenarios also help to clarify the interrelation between functional and non-functional requirements. We have validated our strategy and the related representations based on case studies.
14893766
Improving Web Information Systems with Navigational Patterns
In this paper we show how to improve the architecture of Web information systems (WIS) using design patterns, in particular navigational patterns. We first present a framework to reason about the process of designing and implementing these applications. Then we introduce navigational patterns and show some prototypical patterns. We next show how these patterns have been used in some successful WIS. Finally, we explain how patterns are integrated into the development process of WIS.
7589770
Specifying Quality Characteristics and Attributes for Websites
In this work, we outline more than a hundred characteristics and attributes for the domain of academic sites in order to analyze the quality requirement tree and a way to specify them. These elements are used in a quantitative methodology for assessment, comparison, and ranking processes. The proposed Web-site Quality Evaluation Methodology (QEM) can be a useful approach to assess the quality in different phases of a Web product life cycle. In the academic study, we have observed three different evaluation audiences regarding visitor users: current and prospective students, academic personnel, and research sponsors. Besides, the aim of this work is to show a hierarchical and descriptive specification framework for characteristics, subcharacteristics and attributes. This framework is a key underlying piece in the construction of a hyperdocumented evaluation tool. Finally, some results are presented and concluding remarks are discussed.
47231847
Enhancing a requirements baseline with scenarios
Scenarios are well recognized as an important strategy towards understanding the interface between the environment and the system, as well as a means to elicit and specify software behavior. We have a broader understanding of scenarios: for us, a scenario is an evolving description of situations in the environment. Our proposal is framed by Leite's (1995) work on a client-oriented requirements baseline, which aims at modeling the external requirements of a software system and its evolution. Scenarios start by describing the environmental situation, according to the main actions performed outside the software system. Scenarios also help the clarification of the interrelation between functional and non-functional requirements. We have validated our strategy and related representations based on case studies of a real situation.