This chapter and the next one give a tutorial introduction to Zélus. This chapter focuses on the synchronous kernel of the language, which is reminiscent of Lustre and Lucid Synchrone. We shall sometimes compare Zélus with those two languages. The next chapter focuses on newer, hybrid aspects, like ODEs, zero-crossings, and their interaction with the synchronous features. The simulation engine is described in chapter 3.
Familiarity with general programming languages is assumed. Some familiarity with (strict or lazy) ML languages and with existing synchronous data-flow languages like Lustre is helpful but not mandatory. Some references are given at the end of this document.
In this tutorial, we suppose that programs are written in a file called