Communicating with computers by some means of human or natural language has long been a goal of their users. The very terms "computer language, programming language" illustrate the aim to construct more flexible and more powerful means of communication than is suggested by the simple term "program"' And the development of computer languages like Lisp illustrates steps toward a goal approximating the communication medium for human beings. Yet natural language provides much of its power and flexibility through characteristics which have not been incorporated into computer languages, and may be incorporated only through great ingenuity. For a device lacking the capabilities of the human brain, the properties of human or natural language which provide that power and flexibility will have to be developed by specialists in computing. As has already been learned over two decades of struggle by linguists, humanists, and others who have slowly sought to process natural language as well as, quickly, and in as large quantities as could be done for numbers, the ambiguities of human speech create problems and challenges. In the suc