The formal description of objects is well known and has long been standard practice in many fields. Machine parts, for example, are commonly described by engineering drawings made according to standards which have nearly universal acceptance. The problem of design automation is to take such a description of an object, combine it with information about manufacturing methods and facilities, and automatically generate a formal description of a process which will produce the desired object. In a simple case this may mean no more than generating a tape for a numerically controlled machine tool, while in more complex cases it may require, as intermediate steps, the generation of parts lists and the design of subassemblies.

The underlying logical structure of parallel-search memories is described; the characteristic operation of three major types is displayed in the execution of searches based on equality; and algorithms are presented for searches based on other specifications including maximum, miniTnum, greater than, less than, nearest to, between limits, and ordering (sorting). It is shown that there is a hierarchy of dependency among these algorithms, that they appear in pairs with each member of a pair belonging to one or the other of two distinct classes, and that every type of search can be executed within each class.