Li-Fan Chen says to YSITD https://www.hs.ntnu.edu.tw/hsnuwp/wp-content/uploads/2017/10/APx-%e7%84%a1%e7%b7%9a%e7%b6%b2%e8%b7%af%e9%80%a3%e7%b7%9a%e8%aa%aa%e6%98%8e.pdf