List Processing

List processing is simultaneously three things in the development of computer science. It created a genuine dynamic memory structure in a machine that had heretofore been perceived as having fixed structure. Two, it was an early demonstration of the basic abstraction that a computer consists of a set of data types and a set of operations proper to these datotypes. Three, thist processing produced a model of designation, thus defining symbol manipulation in the sense in which we use this concept in computer science to day. We come now to the evidence for the hypothesis that physical physica symbol systems are capable of intelligent action, and that general intelligent action calls for a physical symbol system.