The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
Recent advances in logic programming have been successfully used to build practical verification toolsets, as evidenced by the XMC system. Thus far, XMC has supported value-passing process languages, but has been limited to using the propositional fragment of modal mucalculus as the property specification logic. In this paper, we explore the use of data variables in the property logic. In particular,...
We describe practical experiences of using a logic programming based approach to model and reason about concurrent systems. We argue that logic programming is a good foundation for developing, prototyping, and animating new specification languages. In particular, we present the new high-level specification language CSP(LP), unifying CSP with concurrent (constraint) logic programming, and which we...
Functional Reactive Programming (FRP) is a declarative programming model for constructing interactive applications based on a continuous model of time. FRP programs are described in terms of behaviors (continuous, time-varying, reactive values), and events (conditions that occur at discrete points in time). This paper presents Frappé, an implementation of FRP in the Java progamming language...
Subject directories and search engines are the most commonly used tools to search for information on the World Wide Web. We propose a novel notion of subject meta-directory on top of standard subject directories, which strongly resembles the way in which metasearch engines extend standard search engines. After analyzing the main choices arising in the design of subject meta-directories, we describe...
In this paper we show how an agent programming language, based on a formal theory of actions, can be employed to implement adaptive web applications, where a personalized dynamical site generation is guided by the user’s needs. For this purpose, we have developed an on-line computer seller in DyLOG, a modal logic programming language which allows one to specify agents acting, interacting, and planning...
We propose a new approach to program web services. Although we base our approach on the Common Gateway Interface (CGI) to ensure wide applicability, we avoid many of the drawbacks and pitfalls of traditional CGI programming by providing an additional abstraction layer implemented in the multi-paradigm declarative language Curry. For instance, the syntactical details of HTML and passing values with...
We explore the use of a number of Logic Programming techniques for generating dynamic Web content and the underlying architecture and implementation issues. We describe a Prolog to VRML mapping allowing generation of dynamic VRML pages through CGI and server side Prolog scripts. BinProlog’s Assumption Grammars (a form of multi-stream DCGs with implicit arguments and temporary assertions, scoping over...
We model any network configuration arising from the execution of a security protocol as a soft constraint satisfaction problem (SCSP). We formalise the protocol goal of confidentiality as a property of the solution for an SCSP, hence confidentiality always holds with a certain security level. The policySCSP models the network configuration where all admissible protocol sessions have terminated successfully,...
We show how deductive databases may be protected against unauthorized retrieval and update requests issued by authenticated users. To achieve this protection, a deductive database is expressed in an equivalent form that is guaranteed to permit only authorized actions. When a user poses a query Q on the protected form of a database, the user sees the subset of the answers for Q that they are permitted...
Programming with rewrite rules and strategies has been already used for describing several computational logics. This paper describes the way the Needham-Schroeder Public-Key protocol is specified in ELAN, the system developed in Nancy to model and compute in the rewriting calculus. The protocol aims to establish a mutual authentication between an initiator and a responder that communicate via an...
The goal of this project is to develop solutions to enhance interoperability between bioinformatics applications. Most existing applications adopt different data formats, forcing biologists into tedious translation work. We propose to use of Nexus as an intermediate representation language. We develop a complete grammar for Nexus and we adopt this grammar to build a parser. The construction heavily...
The goal of this paper is to test if a programming methodology based on the declarative language A-Prolog and the systems for computing answer sets of such programs, can be successfully applied to the development of medium size knowledge-intensive applications. We report on a successful design and development of such a system controlling some of the functions of the Space Shuttle.
Intelligence and interaction are two key -issues in the engineering of todaycomp lex systems, like Internet-based ones. To make logic languages accomplish their vocation of sound enabling technologies for intelligent components, we first need their implementations to strictly meet some engineering properties such as deployability, configurability, and scalability. Then, we should provide...
Logic programming is based on the idea that computation is controlled inference. The Extended Andorra Model provides a very powerful framework that supports both co-routining and parallelism. We present the BEAM, a design that builds upon David H. D.Warren’s original EAM with Implicit Control. The BEAM supports Warren’s original EAM rewrite rules plus eager splitting and sequential conjunctions. We...
The lion’s share of datalog features have been incorporated into the SQL3 standard proposal. However, most SQL manuals still recommend to implement user-defined conditions for data integrity nondeclaratively, by triggers or stored procedures. We describe how to implement known declarative database technology for integrity checking in SQL databases. We show how to represent and evaluate arbitrarily...
We propose high-level type constructors for constraint programming languages, so that constraint satisfaction problems can be modelled in very expressive ways. We design a practical set constraint language, called esra, by incorporating these ideas on top of opl. A set of rewrite rules achieves compilation from esra into opl, yielding programs that are often very similar to those that a human opl...
The problem of deciding timed bisimilarity has received increasing attention; it is important for verification of timed systems. Using a characterization of timed bisimilarity in terms of models of constraint databases, we present to our knowledge, the first local, symbolic algorithm for deciding timed bisimilarity; previous algorithms were based on a finite, but prohibitively large, abstraction (the...
We extend Temporal Annotated Constraint Logic Programming (TACLP) in order to obtain a framework where both temporal and spatial information can be dealt with and reasoned about. This results in a conceptually simple, uniform setting, called STACLP (Spatio-Temporal Annotated Constraint Logic Programming), where temporal and spatial data are represented by means of annotations that label atomic first-...
In constraint solvers, variable and value ordering heuristics are used to finetune the performance of the underlying search and propagation algorithms. However, few guidelines have been proposed for when to choose what heuristic among the wealth of existing ones. Empirical studies have established that this would be very hard, as none of these heuristics outperforms all the other ones on all instances...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.