We would like to thank the following sponsors and funding agencies for supporting our research.

• Uni Kyoto-Inria associate team grant — Inria, France
• Natural Sciences and Engineering Research Council of Canada (NSERC) — Canada
• National Natural Science Foundation of China (NSFC) — China
• National Institute of Informatics visiting research grant — Japan
• Singapore Management University visiting research grant — Singapore
• Science and Technology Foundation of Xiamen — China
• Science Foundation of Huaqiao University — China