A Graphical Representation And Prototype Editor For The Formal Description Technique Estelle

: This paper presents a graphical representation for the Formal Description Technique Estelle, which has up until now been restricted to a textual syntax based on the general programming language Pascal. The graphical syntax and semantics of the representation are fully descriptive of a general Estelle system and complies with the ISO Estelle standard [ISO97]. This representation aims to become a standard technique for formally specifying and simultaneously documenting concurrent, communicating systems. Conventions introduced in existing graphical Estelle tools are re-used, as are graphical concepts which have become familiar through widespread use of the similar Specification and Description Language (SDL). In addition, we present a syntax-directed editor based on the graphical syntax. The editor enables practical application of the graphical technique, by translating a graphical description to the equivalent textual form which can be input into existing Estelle tools. T..