Abstract
Good design and implementation are necessary but not sufficient pre-requisites for successfully reusing object-oriented frameworks. Although not always recognized, good documentation is crucial for effective framework reuse, and often hard, costly, and tiresome, coming with many issues, especially when we are not aware of the key problems and respective ways of addressing them. Based on existing literature, case studies and lessons learned, the authors have been mining proven solutions to recurrent problems of documenting object-oriented frameworks, and writing them in pattern form, as patterns are a very effective way of communicating expertise and best practices. This paper presents a small set of patterns addressing problems related to the framework documentation itself, here seen as an autonomous and tangible product independent of the process used to create it. The patterns aim at helping non-experts on cost-effectively documenting object-oriented frameworks. In concrete, these patterns provide guidance on choosing the kinds of documents to produce, how to relate them, and which contents to include. Although the focus is more on the documents themselves, rather than on the process and tools to produce them, some guidelines are also presented in the paper to help on applying the patterns to a specific framework. © 2011 Springer-Verlag Berlin Heidelberg.

Abstract
The purpose of this paper is to present a first step in a formal study of inheritance systems. The kind of systems considered are those that support overriding (all definitions being taken as defaults) and multiple inheritance. The overriding is based on the explicit statement of negative information. The basic entities are classes and properties. The system is hierarchic because it is made out of classes which are structured as a hierarchy. We consider both the basic case of properties restricted to atomic propositional formulas and their negations, and the extension to properties defined by rules in the Logic Programming style. A formal definition of hierarchic systems is given for which a model-theoretic 3-valued semantics is introduced. This semantics is explicitly stated in terms of sets of individuals. It defines the notion of interpretation, the characterization of models, and what is meant by validity of formulas in such structures. The inheritance mechanism is able to choose from a set of inherited default properties which ones mechanism be overriden in order to guarantee that the local program has a model. The notion of characteristic individuals of classes, introduced in our semantics, turns out to play a clarifying role of the relationship between semantic and syntactic aspects of inheritance systems.

Abstract
This paper1 contains a proposal for a knowledge representation formalism based on a taxonomy of theories. It aims at clarifying the notions of inheritance and dependency among properties and classes, which are mixed together in the “inheritance networks” formalism, while also providing more expressiveness. A model-theoretic semantics in terms of sets of individuals is presented, which is parametric on the characterization of specificity. The case most thoroughly presented is rule inheritance which builds on the assumption that only facts have the force to impose overriding. A double denotation for classes, corresponding to two nested sets, is the key for interpreting defaults and exceptions. The problem of ambiguity propagation in the resulting system is addressed in the context of a discussion of the relationship between it and inheritance nets. © Springer-Verlag Berlin Heidelberg 1993.

Abstract
The purpose of this paper is to present a first step in a formal study of inheritance systems. The kind of systems considered are those that support overriding (all definitions being taken as defaults) and multiple inheritance. The overriding is based on the explicit statement of negative information. The basic entities are classes and properties. The system is hierarchic because it is made out of classes which are structured as a hierarchy. We consider both the basic case of properties restricted to atomic propositional formulas and their negations, and the extension to properties defined by rules in the Logic Programming style. A formal definition of hierarchic systems is given for which a model-theoretic 3-valued semantics is in roduced. This semantics is explicitly stated in terms of sets of individuals. It defines the notion of interpretation, the characterization of models, and what is meant by validity of formulas in such structures. The inheritance mechanism is able to choose from a set of inherited default properties which ones must be overriden in order to guarantee that the local program has a model. The notion of characteristic individuals of classes, introduced in our semantics, turns out to play a clarifying role of the relationship between semantic and syntactic aspects of inheritance systems. © Springer-Verlag Berlin Heidelberg 1991.

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