5 Related Work

  VDM-SL [Jon86], VDM++ [DvK92] and a number of other specification languages allow a mixture of explicit and implicit specification for a single procedure. The rational behind this is to simplify the creation of specifications. Admitting this benefit, we stress the necessity to reveal selected information about a component, as argued in Sect. 2.

The human factor in specification language design has been taken into consideration by e.g., Larch/C++ [Lea96], which is a superset of a subset of C++. Other attempts to make the specification language similar to the envisaged implementation language, respectively make it part of it include the Interface Specification Language (ISL), a pure extension of the CORBA IDL, developed in the Component-Based Software Engineering project at CSTaR Software Engineering Lab and Eiffel [Mey92].