1. School of Mathematics, Hangzhou Normal University, Hangzhou 311121, Zhejiang, China
2. ESIME-Zacatenco, Instituto Politécnico Nacional, Edif. 4, 1er. Piso, Col. Lindavista CP 07738, CDMX
3. Institute of Mathematics, Henan Polytechnic University, Jiaozuo 454010, Henan, China
4. School of Mathematics and Physics, Hulunbuir University, Inner Mongolia 021008, China
5. Independent researcher, Dallas, TX 75252-8024, USA