Introduction.

The directory auto/07p/demos has a large number of subdirectories, for example ab, pp2, exp, etc., each containing all necessary files for certain illustrative calculations. Each subdirectory, say xxx, corresponds to a particular equation and contains one equations-file xxx.{f90,f,c} and one or more constants-files c.xxx.i, one for each successive run of the demo. To see how the equations have been programmed, inspect the equations-file. To understand in detail how AUTO is instructed to carry out a particular task, inspect the appropriate constants-file. In this chapter we describe the tutorial demo cusp in detail. A brief description of other demos is given in later chapters.