SLAN-4: A Language for the Specification and Design of Large Software Systems

The language SLAN-4 has been defined in view of the need for formal tools supporting the specification and design of large software systems. It offers its users language constructs for algebraic and axiomatic specifications as well as for design in pseudocode. One of its major design goals has been to ease subsequent refinements of a (given) specification. The user can start his development with an informal high-level specification which can be formalized and implemented at a later date by using lower-level concepts. This paper provides the formal definitions of the SLAN-4 language, discusses the design decisions, and presents examples for the use of the syntactic constructs.