1 - Bisimulation in Algebraic Specifications

Abstract

Abstract data types are included in programming languages such as Ada, CLU, MODULA, CIP-L, or ML to provide a syntactic frame for the modular and abstract definition of programming systems. Therefore, programming languages are also described by these techniques. Main steps in this direction are infinite magmas, the ADJ-approach using continuous algebraic theories, the abstract semantic algebras, the ACP-framework, and the CIP-project at Munich. This chapter discusses the hierarchical approach to abstract data types based on partial algebra semantics as it has been pursued in the CIP-project at Munich. In this framework, deterministic and nondeterministic as well as applicative and procedural programming language constructs have been formalized. These algebraic techniques have also been applied to formalize a parameterized schema for the specification of concurrent systems in the framework of the SMoLCS methodology that has been used to give the dynamic semantics of full Ada. In particular, the semantics of the intermediate language, which formalizes the concurrent structure of Ada, has been given by an algebraic specification where processes are viewed as labeled transition systems, thus generalizing an idea underlying CCS.