*1:See also https://sumita-m.hatenadiary.com/entry/20060515/1147667307 https://sumita-m.hatenadiary.com/entry/20160821/1471789887 https://sumita-m.hatenadiary.com/entry/20160824/1472007786 https://sumita-m.hatenadiary.com/entry/2020/04/28/022530 https://sumita-m.hatenadiary.com/entry/2020/05/06/102459 https://sumita-m.hatenadiary.com/entry/2020/05/08/011324
*2:See also https://sumita-m.hatenadiary.com/entry/2019/08/20/073933 https://sumita-m.hatenadiary.com/entry/2020/03/19/023253