  This paper investigates the usefulness of PSF in software engineering and
reengineering. PSF is based on ACP (Algebra of Communicating Processes) and as
some architectural description languages are based on process algebra, we
investigate whether PSF can be used at the software architecture level, but we
also use PSF at lower abstract levels. As a case study we reengineer the
compiler from the Toolkit of PSF.
