*1:See also https://sumita-m.hatenadiary.com/entry/2020/07/17/005025 https://sumita-m.hatenadiary.com/entry/2020/07/27/094030 https://sumita-m.hatenadiary.com/entry/2020/07/31/013249 https://sumita-m.hatenadiary.com/entry/2020/10/30/123949 https://sumita-m.hatenadiary.com/entry/2020/11/18/132140 https://sumita-m.hatenadiary.com/entry/2020/11/22/225415 https://sumita-m.hatenadiary.com/entry/2020/12/08/103219