If you are new to the system and want to start using the tool as quickly
as possible and learn by trying things out instead of reading a lenghty
manual, you might want to start from next section directly.
+ - \ref GRAS_tut_intro_what
+ - \ref GRAS_tut_intro_model
- \ref GRAS_tut_tour :\n
This section aims at turning new-comers into GRAS power user. It briefly