*1:See also https://sumita-m.hatenadiary.com/entry/2021/09/07/095646
*2:See also https://sumita-m.hatenadiary.com/entry/20150730/1438223216 https://sumita-m.hatenadiary.com/entry/2020/04/06/014410 https://sumita-m.hatenadiary.com/entry/2020/05/18/091354 https://sumita-m.hatenadiary.com/entry/2020/12/23/133417 https://sumita-m.hatenadiary.com/entry/2021/02/02/144734 https://sumita-m.hatenadiary.com/entry/2021/02/06/185051 https://sumita-m.hatenadiary.com/entry/2021/03/04/212712 https://sumita-m.hatenadiary.com/entry/2021/03/12/022336 https://sumita-m.hatenadiary.com/entry/2021/03/30/081149 https://sumita-m.hatenadiary.com/entry/2021/04/01/025541 https://sumita-m.hatenadiary.com/entry/2021/04/13/082743 https://sumita-m.hatenadiary.com/entry/2021/07/05/081103 https://sumita-m.hatenadiary.com/entry/2021/08/01/093500 https://sumita-m.hatenadiary.com/entry/2021/08/02/014655 https://sumita-m.hatenadiary.com/entry/2021/08/04/100738