24 Abset, a Programming Language Based on Sets: Motivation and Examples E. W. Elcock, J. M. Foster, P. M. D. Gray, J. J. McGregor and A. M. Murray

The overall design aim of ABSET was to devise an interactive programming language in which it is possible, at will, to take or defer decisions about a program: we therefore require that decisions which are logically separable can indeed be taken separately and in aiiy order. Further, we think it important that the language should allow the nature of each decision to be clear, particularly choice of representations.