*1:See also https://sumita-m.hatenadiary.com/entry/2020/02/02/133228 https://sumita-m.hatenadiary.com/entry/2020/03/23/023106 https://sumita-m.hatenadiary.com/entry/2020/03/27/142245 https://sumita-m.hatenadiary.com/entry/2020/11/12/093301 https://sumita-m.hatenadiary.com/entry/2020/12/04/123636 https://sumita-m.hatenadiary.com/entry/2021/02/19/121852 https://sumita-m.hatenadiary.com/entry/2021/03/10/200121