Thus far, the only means we have seen of providing information to a Prolog program has been by asking questions of the Prolog system. Also, the only method of finding out what a variable stands for at some point in the satisfaction of a goal has been by asking a question in such a way that Prolog will print out the answer in the “X = answer” form. Much of the time, such direct interaction with questions is all that is required to ensure that a program is working properly. However, for many occasions it is useful to write a Prolog program that initiates a conversation with you by itself.
Unable to display preview. Download preview PDF.