*1:See also https://sumita-m.hatenadiary.com/entry/2020/03/09/132415 https://sumita-m.hatenadiary.com/entry/2020/07/23/140730 https://sumita-m.hatenadiary.com/entry/2020/11/13/151607 https://sumita-m.hatenadiary.com/entry/2021/03/25/160053 https://sumita-m.hatenadiary.com/entry/2021/05/12/161513 https://sumita-m.hatenadiary.com/entry/2021/06/07/072609