1. Key Laboratory of High Confidence Software Technologies (Ministry of Education), School of Computer Science, Peking University, China
2. School of Computer Science, Peking University, China
3. University of California San Diego, USA
4. Institute of Software, Chinese Academy of Sciences and University of Chinese Academy of Science, China
5. Macquarie University, Australia
6. School of Computer Science, School of Electronics Engineering and Computer Science, Peking University, Beijing, China
7. Key Laboratory of High Confidence Software Technologies (Ministry of Education), School of Computer Science, School of Electronics Engineering and Computer Science, Peking University, China and Telecom SudParis, France