(Relational) programming laws in the boom hierarchy of types

Abstract

In this paper we demonstrate that the basic rules and calculational techniques used in two extensively documented program derivation methods can be expressed, and, indeed, can be generalised within a relational theory of datatypes. The two methods to which we refer are the so-called “Bird-Meertens formalism” (see [22]) and the “Dijkstra-Feijen calculus” (see [15]). The current paper forms an abridged, though representative, version of a complete account of the algebraic properties of the Boom hierarchy of types [19, 18]. Missing is an account of extensionality and the so-called cross-product.