Specification and animation of a bank transfer

The development of formal specifications may benefit from prototyping activities. The production of an executable model for a given description helps bridging the gap between this specification and the corresponding reality. The KIDS/VDM system, based on the KIDS environment, provides these prototyping facilities for the model-based specification language of VDM. This paper illustrates its use in the specification of a bank transfer operation. It shows how animation may be helpful at several stages of a specification process based on a series of refinements of an initial abstract specification.