*1:See also https://sumita-m.hatenadiary.com/entry/2020/01/15/103151 https://sumita-m.hatenadiary.com/entry/2020/05/15/142141 https://sumita-m.hatenadiary.com/entry/2020/11/02/105527 https://sumita-m.hatenadiary.com/entry/2021/01/05/025458 https://sumita-m.hatenadiary.com/entry/2021/03/06/101444 https://sumita-m.hatenadiary.com/entry/2021/03/22/143416 https://sumita-m.hatenadiary.com/entry/2021/05/03/092932