Résumé:
We first of all thank Allah "the Almighty, for giving us courage and
patience, and for guiding us to where we have arrived.
We would like to extend our sincere thanks to the people who have given
us their assistance and who have contributed to the development of this
brief.
We address a big thank you to the person in charge of this memory, Mme.
Benabid Sonia for her precious help and for the time she devoted to us as
well as for the help she gave us.
It is a pleasure for us as much as a duty to thank all the people who have
been able to contribute directly or indirectly to the accomplishment of
this project.
