Elan-0 is a small subset of Elan, which is intended for learning systematic Top-Down programming. The best way to get acquainted with Elan and to appreciate the programming style it aims to support is to start with the Elan-0 subset.
This chapter of the manual is intended for readers who already have some experience in programming in an algorithmic language. Notice that a careful distinction is made between remarks which pertain to Elan as a whole and remarks confined to the Elan-0 subset. In chapter 4 the syntax of the full language (with the exception of packets) can be found, which is available in the Elan Programming Environment.