*1:See also https://sumita-m.hatenadiary.com/entry/2020/02/03/103223 https://sumita-m.hatenadiary.com/entry/2020/02/22/103043 https://sumita-m.hatenadiary.com/entry/2020/03/04/022634 https://sumita-m.hatenadiary.com/entry/2020/03/06/095341 https://sumita-m.hatenadiary.com/entry/2020/05/26/090808 https://sumita-m.hatenadiary.com/entry/2020/06/17/083510