Constructive consistency checking for partial specification in Z

Partial specification is a method of specifying complex systems in which the system is described by a collection of specifications, each approaching the system from a different viewpoint. The specification notation Z is often advocated as a suitable language for this style of specification. For collections of partial specifications to be meaningful, they need to be consistent, i.e. they should not impose contradictory requirements. This paper addresses how consistency between partial specifications in Z can be checked, by constructing unifications, i.e. least common refinements, of viewpoint specifications.