Motivated by the close relation between real-time and fault tolerance, we investigate the foundations of a forma! framework to specify and verify real-time distributed systems that incorporate fault tolerance techniques. Therefore a denotational semantics is presented to describe the real-time behaviour of distributed programs in which concurrent processes communicate by synchronous messa.ge pa...

The aim of our work is the modelling and design of information systems in the object-oriented setting. An object-oriented spec-iication covers structural as well as behavioural aspects of the system. A possibility to describe system dynamics is to use a temporal logic as it is done in the formal object-oriented speciication language Troll. Temporal logics is particularly suited to deal with tem...

This paper is about meaning, in the following sense: If a system employs symbols, in what sense are they symbolic, of what are they symbolic, and in what sense is it the system that makes them symbolic? In other words, what does it take for a system to be such that the question "what do you mean by that?" can be appropriately asked it? We suggest an answer based on the idea of quotation or reif...

As I have argued elsewhere [10], and as summarized in the first two sections below, it turns out to be both logically and semantically revealing to acknowledge the existence of converse, or conversely construed, quantifiers, which mirror their classical, or classically construed, counterparts. In this paper I argue that classically construed quantifiers in their turn mirror their conversely con...

Motivated by the close relation between real-time and fault tolerance, we investigate the foundations of a forma! framework to specify and verify real-time distributed systems that incorporate fault tolerance techniques. Therefore a denotational semantics is presented to describe the real-time behaviour of distributed programs in which concurrent processes communicate by synchronous messa.ge pa...

Motivated by the close relation between real-time and fault tolerance, we investigate the foundations of a forma! framework to specify and verify real-time distributed systems that incorporate fault tolerance techniques. Therefore a denotational semantics is presented to describe the real-time behaviour of distributed programs in which concurrent processes communicate by synchronous messa.ge pa...

Reiication is a popular technique to reduce complexity of the software design process. This technique has to be re-investigated for the comprehensive object-oriented approach. Object-oriented speciications comprise structure and behavior of systems. Due to this sophisticated idea two kinds of reiication appear: data reiication and action reiication. In this paper we present an approach to incor...

Motivated by the close relation between real-time and fault tolerance, we investigate the foundations of a forma! framework to specify and verify real-time distributed systems that incorporate fault tolerance techniques. Therefore a denotational semantics is presented to describe the real-time behaviour of distributed programs in which concurrent processes communicate by synchronous messa.ge pa...

Motivated by the close relation between real-time and fault tolerance, we investigate the foundations of a forma! framework to specify and verify real-time distributed systems that incorporate fault tolerance techniques. Therefore a denotational semantics is presented to describe the real-time behaviour of distributed programs in which concurrent processes communicate by synchronous messa.ge pa...

This paper discusses the role of accountability in responsibility ascriptions regarding information and communication technology (ICT). It starts with a definition of responsibility as the social construct representing the ascription of an object to a subject. Recounting the traditional responsibility, the paper will point out the weaknesses of responsibility with regards to ICT. It will then p...