*Aboussaghid Alkabouss Sakha*, from Niger, PhD Student in Mathematics at the Cheikh Anta Diop University

*Abdoulaye Maïga*, from Mali, PhD Student in Mathematics at Cheikh Anta Diop University

*Mohamadou Sall,* Cheikh Anta Diop University , Senegal, PhD Student in Mathematics

*Michel Seck,* Cheikh Anta Diop University, PhD Student in Mathematics

*Bang Biang Narcisse*, Univ Bamenda, Cameroun, PhD Student in Mathematics