Formal Specification of User Interfaces: A Comparison and Evaluation of Four Axiomatic Approaches

Few examples of formal specification of the semantics of user interfaces exist in the literature. This paper presents a comparison of four axiomatic approaches which we have applied to the specification of a commercial user interface–the line editor for the Tandy PC-1 Pocket Computer. These techniques are shown to result in complete and relatively concise descriptions. A number of useful and nontrivial properties of the interface are formally deduced from one of the specifications. In addition, a direct implementation of the interface is constructed from a formal specification. Limitations of these specification examples are discussed along with future research work.