*1:See also https://sumita-m.hatenadiary.com/entry/2020/05/21/032916 https://sumita-m.hatenadiary.com/entry/2021/09/27/080850
*2:See also https://sumita-m.hatenadiary.com/entry/20070327/1175000516 https://sumita-m.hatenadiary.com/entry/2020/02/13/094030 https://sumita-m.hatenadiary.com/entry/2020/05/06/075437 https://sumita-m.hatenadiary.com/entry/2020/06/04/100959