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For the extension of high level languages by data types of mode relation, three language constructs are proposed and discussed: a repetition statement controlled by relations, predicates as a generalization of Boolean expressions, and a constructor for relations using predicates. The language constructs are developed step by step starting with a set of(More)
Scoping, naming and binding are central concepts in the deenition and understanding of programming languages. With the introduction of sophisticated data models, these issues become important for query languages as well. Additionally, the goal of integrating query and programming languages requires a common basis for their operational semantics. We ooer(More)
A Three-Facet Information D ealing with change is one of the most fundamental challenges facing IS professionals today. Business process restructuring, shifting alliances and new competitors , deregulation and globalization , legacy system migration, and new technology adoption, are but a few of the economical, organizational , and technological forces(More)
In the process of developing an Information System, one passes through stages that include requirements gathering, design specification, and software implementation. The purpose of the TDL language is to express the conceptual design of an information system; it is the intermediate language in a triad that includes the language Telos, which captures an(More)
Relational databases use predicates for a large variety of different functions. some leading to database search, others being handled by theorem proving. First we demonstrate that the theorem provinr! applications have very similar basic requirements for predicate mana-eement but differ in their need foti efficiency. Second we Gresent dedicated deduction(More)
We present a framework for the development of information systems based on the premise that the knowledge that influences the development process needs to somehow be captured, represented, and managed if the development process is to be rationalized. Experiences with a prototype environment developed in ESPRIT project DAIDA demonstrate the approach. The(More)