Certum quod factum.
(One is certain of only what one builds.)
– Giovanni Battista Vico (1668–1744)
Italian royal historiographer
You will never become proficient in a foreign language by studying vocabulary lists. Rather, you must hear and speak (or read and write) the language to gain proficiency. The same is true for learning computer languages.
This chapter shows how to combine the basic functions and special forms of Lisp into a complete program. If you can learn how to do that, then acquiring the remaining vocabulary of Lisp (as outlined in chapter 3) will be easy.
The program we will develop in this chapter generates random English sentences. Here is a simple grammar for a tiny ...