powerful operations on them. An early step in this direction was the development of APl, and more recent examples have been SETl which enables a user to code in terms of mathematical enti- ties such as sets and BDl which allows a user, presumably a businessman, to specify a computation in terms of a series of tabular forms and a series of processing paths through which data flows. The design and implementation of such languages are examined in chapters by P. GOLDBERG. Another extension to traditional methods is made possible by systems designed to automatically handle low level flow-of-...