*1:See also https://sumita-m.hatenadiary.com/entry/2021/01/14/005415 https://sumita-m.hatenadiary.com/entry/2021/01/28/002235 https://sumita-m.hatenadiary.com/entry/2021/03/20/121004 https://sumita-m.hatenadiary.com/entry/2021/03/24/230921 https://sumita-m.hatenadiary.com/entry/2021/06/02/093438 https://sumita-m.hatenadiary.com/entry/2021/06/03/073508 https://sumita-m.hatenadiary.com/entry/2021/06/06/090235
