*1:See also https://sumita-m.hatenadiary.com/entry/20170407/1491538185 https://sumita-m.hatenadiary.com/entry/2021/06/12/072847 https://sumita-m.hatenadiary.com/entry/2021/09/19/171216
*2:See also https://sumita-m.hatenadiary.com/entry/2020/08/02/104833 https://sumita-m.hatenadiary.com/entry/2021/06/12/072847
