Scientific Reports 3, Article number: 2993 (2013); Published: 21 October 2013; Updated: 17 November 2014

This Article contains an error in the Acknowledgements section:

“This work was supported by National Basic Research Program of China (2013CB329305), National Natural Science Foundation of China (61332012, 61303110), 100 Talents Programme of The Chinese Academy of Sciences, Strategic Priority Research Program of the Chinese Academy of Sciences (XDA06030601) and Open Project Program of Key Laboratory of Symbolic Computation and Knowledge Engineering of Ministry of Education (93K172013K02).”

should read:

“This work was supported by National Natural Science Foundation of China (61332012), National Basic Research Program of China (2013CB329305), National Natural Science Foundation of China (61303110), 100 Talents Programme of The Chinese Academy of Sciences, Strategic Priority Research Program of the Chinese Academy of Sciences (XDA06030601) and Open Project Program of Key Laboratory of Symbolic Computation and Knowledge Engineering of Ministry of Education (93K172013K02).”