In this section, the routines that have to be supplied by the user in order to run the programs, are described. Therefore the general scheme is sketched here. The number of user routines is quite large, but most routines can be replaced by empty or short routines, if no special action is needed.
Figure 1 shows the calling tree of the relevant functions and subroutines. Routines printed in typewriter have to be supplied by the user and are described in detail below, functions in italic and roman are provided by the corresponding cross-section Monte Carlo and the library, respectively.
