*1:See also https://sumita-m.hatenadiary.com/entry/2020/04/06/014410 https://sumita-m.hatenadiary.com/entry/2020/05/25/082501 https://sumita-m.hatenadiary.com/entry/2020/08/03/103144 https://sumita-m.hatenadiary.com/entry/2020/10/01/092639 https://sumita-m.hatenadiary.com/entry/2020/11/28/143913 https://sumita-m.hatenadiary.com/entry/2020/12/12/210119 https://sumita-m.hatenadiary.com/entry/2020/12/21/094527 https://sumita-m.hatenadiary.com/entry/2020/12/28/080130 https://sumita-m.hatenadiary.com/entry/2020/12/29/112402 https://sumita-m.hatenadiary.com/entry/2021/01/03/090242 https://sumita-m.hatenadiary.com/entry/2021/01/28/002235 https://sumita-m.hatenadiary.com/entry/2021/02/14/130140 https://sumita-m.hatenadiary.com/entry/2021/03/20/121004