Introduction to SDL-92

SDL-92 is introduced in the paper, thereby concentrating on its advanced aspects. This especially refers to features of the language not available in SDL-88, the previous version of SDL. The paper shows how SDL deals with abstraction and the use of types within the newly introduced concepts of object-orientation. Other new features dealt with are remote procedures and nondeterminism. An incomplete example illustrates how a system may be specified, thereby making use of a number of the new concepts. Various hierarchical levels, such as system, block, process, procedure and service are covered. Some differences to SDL-88 are listed and the reader is given some advice on further reading and education.