Derivation of Concurrent Algorithms in Tempo

Tempo is a logic programming language that has recently been designed with the aim of allowing concurrent programs to be written in a more declarative manner than existing languages. One of the benefits of declarative programming is the potential for systematic derivation of programs --- the subject of this paper. Here we present a few transformation rules that can be applied to Tempo programs, and then describe in detail the derivation of some concurrent algorithms in Tempo. An outline of the Tempo language is also included in order to make the paper self-contained. 1 Introduction One of the major advantages of the declarative approach to programming is the ability to construct programs systematically from specifications by applying correctnesspreserving transformation rules. Existing programs can be transformed to new, possibly more efficient, programs in the same way. Although it could be argued that the same technique can also be applied to "conventional" languages, it is undoubted..