Department of Mathematics 

  College of Science P.O. Box 36

  Sultan Qaboos University

  Muscat 123

  Sultanate of Oman 

  Tel: +968 2414 2341

  Mobile: +968 92669753

  Fax: +968 24411420

  nao@squ.edu.om

 naovi2026@gmail.com

 albaali@squ.edu.om