First, the 3x+1 problem is transformed into the decision of the terms valued 1 of the all-odd 3x+1 sequences. Then, the property of the all-odd 3x+1 sequences is used to obtain the equations with equal terms and the sufficient and necessary conditions for the all-odd 3x+1 sequences to have equal terms. Then, the uniqueness of the characteristic solutions of the equations with equal terms is proved. At last, based on the above results the 3x+1 problem is proved to be true.

Professor Zhou received B.E. from Department of Automation, Beijing University of Technology in Jan.1982. He received postgraduate graduation diploma from Department of Computer Science, Beijing University of Technology in 1987. He was a lecturer in Department of Computer Science, Beijing University of Technology from 1987 to 1992, an associate professor in College of Information, Beijing Union University from 1992 to 2005, a professor in Institute of Information Technology, College of Information, Beijing Union University from 2005 to 2012, a professor emeritus in College of Smart City, Beijing Union University since 2012. He constructs mutually-inversistic logic and applies it to the fields of computer science and artificial intelligence, such as automated theorem proving, logic programming, planning and scheduling, expert systems, semantic network, program verification, natural language understanding, hardware verification, machine learning, data mining, uncertainty reasoning, program refinement, many-valued computer, etc. He published about 80 refereed papers, authored 4 monographs on them. He was a senior member of China Computer Federation, a supervisor of Beijing Logical Association before his retirement.