Formal specifications were first used in the description of program ming languages because of the central role that languages and their compilers play in causing a machine to perform the computations required by a programmer. In a relatively short time, specification notations have found their place in industry and are used for the description of a wide variety of software and hardware systems. A formal method - like VDM - must offer a mathematically-based specification language. On this language rests the other key element of the formal method: the ability to reason about a specification. Proofs can be empioyed in reasoning about the potential behaviour of a system and in the process of showing that the design satisfies the specification. The existence of a formal specification is a prerequisite for the use of proofs; but this prerequisite is not in itself sufficient. Both proofs and programs are large formal texts. Would-be proofs may therefore contain errors in the same way as code. During the difficult but inevitable process of revising specifications and devel opments, ensuring consistency is a major challenge. It is therefore evident that another requirement - for the successful use of proof techniques in the development of systems from formal descriptions - is the availability of software tools which support the manipu lation of large bodies of formulae and help the user in the design of the proofs themselves."

In his landmark 1942 report on social insurance Sir William Beveridge talked about the 'five giants on the road to reconstruction' - the giants of Want, Disease, Ignorance, Squalor, and Idleness. Social Progress in Britain investigates how much progress Britain has made in tackling the challenges of material deprivation, ill-health, educational standards, lack of housing, and unemployment in the decades since Beveridge wrote. It also asks how progress in Britain compares with that of peer countries - Canada, France, Germany, Italy, Japan, Sweden and the USA. Has Britain been slipping behind? What has been the impact of the increased economic inequality which Britain experienced in the 1980s - has rising economic inequality been mirrored by increasing inequalities in other areas of life too? Have there been increasing inequalities of opportunity between social classes, men and women, and different ethnic groups? And what have been the implications for Britain's sense of social cohesion?