UTP by Example: Designs

摘要

We present a tutorial introduction to the semantics of a basic nondeterministic imperative programming language in Unifying Theories of Programming (UTP). First, we give a simple relational semantics that accounts for a theory of partial correctness. Second, we give a semantics based on the theory of precondition-postcondition pairs, known in UTP as designs. This paper should be read in conjunction with the UTP book by Hoare & He. Our contribution lies in the large number of examples we introduce.