Reflection is a wide-ranging concept that has been studied independently in many different areas of science in general, and computer science in particular. Even in the sub-area of programming languages, it has been applied to different paradigms, especially the logic, functional and objectoriented ones. Partly because of different past influences, but also because researchers in these communities scarcely talk to each others, concepts have evolved separately, sometimes to the point where it is hard for people in one community to recognize similarities in the work of others, not to speak about cross-fertilization among them. In this paper, we propose a synthesis covering mainly the application of computation reflection to programming languages. We compare the different approaches and try to identify similar concepts hidden behind different names or constructs. We also point out the different emphasis that has been given to different concepts in each of them. We do not claim neither comp...

This paper is concerned with the problem of combining deductive and object-oriented features to produce a deductive object-oriented database system which is comparable to those currently available under the relational view of data modelling not only in its functionality but also in the techniques employed in its construction and use. Under this assumption, we highlight the kinds of issues that have to be tackled for a similar research strategy to produce comparable results. We motivate our terms of comparison, characterise three broad approaches to deductive object-oriented databases and introduce the notion of language convergence to help in the characterisation of some shortcomings that have been perceived in them. Three proposals that have come to light in the past three years are looked into in some detail, insofar as they exemplify some of the positions in the space of choices we have defined. The main contribution of the paper is towards a characterisation of the language convergence property of deductive database languages which has a key role in addressing critiques of the deductive and object-oriented database research enterprise. We assume a basic familiarity with notions from deductive databases and from object-oriented databases.

We present the basic principles and possible applications of systems capable of meta-reasoning and reflection. After a discussion of the seminal approaches, we outline our own perception of the state of the art, mainly but not only in computational logic and logic programming. We review relevat successful...

MViews attempts to abstract out the common features of multi-view editing environments that support integrated textual and graphical programming with consistency management. It provides a conceptual model and reusable object-oriented framework for constructing interactive programming environments that provide multiple textual and graphical views. It supports multiple views of a base document, maintaining consistency between each of the views using an update record mechanism. MViews has been used to construct a visual programming environment for an object-oriented language featuring both graphical and textual views of the program. Other applications of MViews under development include entity-relationship and dataflow diagrammers, a visual debugger and a dialog box painter. 1. Introduction Diagrams are useful in all phases of the software lifecycle to help explain and understand concepts that are difficult to describe in text (Davis, 1988). In objectoriented programming, for example, di...

. In this paper, a number of existing solutions and suggestions towards combining the object-oriented (OO) and logic programming paradigms have been briefly studied and categorized, and a sketch of a new solution has been proposed which tries to capture the essence of OO in terms of modal logic, and which could be implemented as a modal logic programming system. The proposal is based on the belief that two orthogonal dimensions - object hierarchy and time - are involved in OO that in many respects are similar. For the one-dimensional (static) case, three logics - MU, MU, and MU² - have been designed, each allowing a different variety of inheritance modes. The two-dimensional (dynamic) case has been treated in a logic 2MU and its corresponding variants. Under certain OO-motivated definitions of Horn clause, the resolution calculi of these logics turn out to be complete. 1 Introduction Since 1983-4 [ST83, Zan84], more than 20 mergers of the OO and logic paradigms (see Section 2) have be...

Metaresoning is again under focus in the AI community. Here in this paper, a new classification for types of metareasoning has been proposed. In recent years, only the ones that are here named as pre-metareasoning and para-metareasoning have been studied. The first one is for predicting the best computation path for having better performance programs. The second, mostly known as interruptible anytime algorithm, is to limit the computation time externally when the approximate answer is better than nothing. One other type of metareasoning (called here as post-metareasoning) is discussed in a case study. It has been shown as an effective method for reducing error in self-localization. Based on the measurements in the case study, the post-metareasoning argued as useful when the effectiveness of reasoning methods are not known by the designer or when the system learns the reasoning methods and should evaluate and use the best one automatically. As the post-metareasoning is based on the results of different isolated reasoning methods, it is possible to be handled in parallel. The speed of post-metareasoning in such a case is determined by the time required by the slowest reasoning method and the post-metaresoning itself.