1. Department of Mathematics: Analysis Logic and Discrete Mathematics, Ghent University, Ghent, Belgium
2. Institute of Mathematics and Mathematical Modeling, Almaty, Kazakhstan
3. Al-Farabi Kazakh National University, Almaty, Kazakhstan
4. LaSIE, Faculté des Sciences, Pole Sciences et Technologies, Université de La Rochelle, La Rochelle Cedex, France
5. NAAM Research Group, Department of Mathematics, Faculty of Science, King Abdulaziz University, Jeddah, Saudi Arabia