Abstract. We extend CASL architectural specifications with a simple refinement language that allows the formalization of developments as refinement trees. The essence of the extension is to allow refinements of unit specifications in CASL architectural specifications. 1 Introduction The standard development paradigm of algebraic specification [1] postulates thatthe development begins with a formal requirement specification SP 0 (extractedfrom a software project's informal requirements) that fixes only expected properties but ideally says nothing about implementation issues; this is to be followedby a number of refinement steps that fix more and more details of the design, until a specification SP n is obtained that is detailed enough that its conversioninto a program

Abstract. In this paper we present various notions of the combined refinement for data and processes within the specification language CSP-CASL. We develop proof support for our refinement notions and demonstrate how to employ them for system development and for system analysis. Finally, we apply our technique to an industrial standard for an electronic payment system. 1

Abstract not found