Preconditions for understanding

Abstract

We argue that advocates of a formal method have an obligation to explain the relationship between the role of proof in that method and the role of proof in others. Such comparisons are needed to (a) clarify the "method" behind a specific notation, (b) dispel misconceptions invited by the use of similar vocabulary with different meanings, and (c) suggest improvements to existing methods. We illustrate these points by comparing the use of preconditions in Z with that in other formal methods.