Abstract
We present a service-oriented scripting language for programming mobile agents in distributed systems. The main novelty of the language we call MOB, is the integration of the service-oriented and mobile agent paradigms. MOB is also encoded onto a process calculus with a well studied semantics. The encoding provides a specification for the front-end of the language compiler and allows us to use, for the back-end and for the run-time system, a compiler and a virtual machine previously developed for the process calculus.

Abstract
In this paper we present MOB, a service-oriented scripting language for programming mobile agents in distributed systems. The main feature of the language is the integration of the service-oriented and the mobile agent paradigms. MOB is encoded onto a process calculus with a well studied semantics which provides us with a tool to prove the soundness of the language relative to the underlying calculus. Copyright 2006 ACM.

Abstract
STEP is an international standard for modeling information used in manufacturing activities; Part 21 is a STEP component that standardizes the exchange of this information through text files. We are working on applying logic programming techniques to processing STEP data models. The STEP standard specifies the entities, attributes, consistency rules, and functions used for describing and validating manufacturing information. Most STEP entities and data types are organized into hierarchies, making an object-oriented approach the most straightforward implementation solution. Our work uses Logtalk, an object oriented extension to Prolog, as the primary implementation tool.

Abstract

Abstract

Abstract
An interesting feature of current Prolog systems is the ability to define external Prolog predicates that can be written in other languages. However, an important drawback of these interfaces is the fact that they lack some important features necessary to improve both the efficiency and the transparent integration of the Prolog system and the external predicates. Such an example is the cut operation. This operation is used quite often in Prolog programs, both for efficiency and semantic preservation. However, its use after a call to an externally defined predicate can have undesired effects. For example, if we have a pending connection to another application, or if we have memory blocks allocated by an external predicate, when a cut operation occurs, we may not be able to perform generic destruct actions, such as closing the pending connection or freeing the unnecessary memory. In this work, we propose an extension of the interface architecture that allows to associate generic user-defined functions with external predicates, in such a way that the Prolog engine transparently executes them when a cut operation occurs. We describe the implementation details of our proposal in the context of the Yap Prolog system.