Vítor Nogueira

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This article merges two approaches: one dealing with persistence for logic programs, as provided by a relational database back-end and another which addresses the issues of logic program structuring, by way of the parametric context. We claim that these two can be effectively combined to obtain a language which offers significant gains in expres-siveness(More)
There has been an increased interest in temporal reasoning from areas such as database systems and AI. In this paper we propose a temporal reasoning framework that bridges the paradigms of Constraint Logic Programming (CLP) and Contextual Logic Programming (CxLP). CLP is used to build a rather simple, yet powerful temporal algebra with points, intervals,(More)
The importance of temporal representation and reasoning is well known to the database community. Examples of such significance are the languages TSQL2 and its follow up, SQL/Temporal. Contextual Logic Programming (CxLP) is a powerful and simple mechanism which addresses the general issue of modularity in Logic Programming. In this paper we propose a(More)
In this article we claim that Contextual Constraint Logic Programming (CCxLP for short) is a powerful paradigm in which to design and implement Organizational Information Systems, particularly when integrated with the ISCO/ISTO mediator framework. We briefly introduce the language and its underlying paradigm, assessing it from the angle of its antecedents:(More)
Albeit temporal reasoning and modularity are very prolific fields of research in Logic Programming (LP), we find few examples of their integration. In this paper we propose the addition of temporal annotations to a modular extension of LP. Moreover, we also provide a sketch for a compiler, allowing this way for the development of applications based on such(More)
Albeit temporal reasoning and modularity are very prolific fields of research in Logic Programming (LP) we find few examples of their integration. Moreover, in those examples, time and modularity are considered orthogonal to each other. In this paper we propose the addition of temporal annotations to a modular extension of LP such that the usage of a module(More)