1. School of Information Sciences and Engineering, Chengdu University, Chengdu610106, China
2. Department of Mathematics, University of Engineering and Technology, Lahore54000, Pakistan
3. Department of Mathematics, COMSATS University of Islamabad, Lahore Campus, Lahore54000, Pakistan
4. Department of Mathematics, Government College University, Lahore54000, Pakistan
5. Department of Mathematics, Minhaj University, Lahore54000, Pakistan