1. Moulay Ismaïl University, Faculty of Science and Technology, Department of Mathematics, Algebra and Applications Group P.O. Box 509, Boutalamine, Errachidia, Morocco
2. Ibn Zohr University, Faculty of Sciences of Agadir, Department of Mathematics, P.O. Box 8106, Agadir, Morocco
3. Moulay Ismaïl University, Faculty of Science and Technology, Computer Science Department, Errachidia, Morocco