Informality in Program Specifications

This paper is concerned with the need for computer-based tools which help human designers formulate formal process-oriented specifications. It first determines some attributes of a suitable process-oriented specification language, then examines the reasons why specifications would still be difficult to write in such a language in the absence of formulation tools. The key to overcoming these difficulties seems to be the careful introduction of informality based on partial, rather than complete, descriptions and the use of a computer-based tool that uses context extensively to complete these descnrptions during the process of constructing a well-formed specification. Some results obtained by a running prototype of such a computer-based tool on a few informal example specifications are presented and, finaliy, some of the techniques used by this prototype system are discussed.