Description of system function is already in use as the basis of an
approach to interpretation of the results of simulation in design analysis,
allowing an automated design analysis tool to generate a textual report
detailing the results of the simulation in terms of its purpose.
This paper presents a novel functional description language that allows
cases where the individual
elements of a required system function themselves constitute
(subsidiary) functions from cases where this is not so. This
increases the expressive power of the functional description, allowing
the automatic generation of design analysis reports of greater
precision than has previously been possible and increases the range of
systems and design analysis tasks for which the approach can be used.