Department of Mathematics, College of Computer Science and Mathematics, University of Mosul, Mosul, Iraq
Department of Mathematics, College of Education for Pure Science, University of Mosul, Mosul, Iraq
Copyright © 2020 Ali Ahmed A. Abdulla, Nada Yassen Kasm Yahya et al. This is
an open access article distributed under the Creative Commons Attribution
License, which permits unrestricted use, distribution, and reproduction in any
medium, provided the original work is properly cited.