*1:See also https://sumita-m.hatenadiary.com/entry/20131004/1380911282 https://sumita-m.hatenadiary.com/entry/2019/01/14/111042 https://sumita-m.hatenadiary.com/entry/2020/04/27/142854 https://sumita-m.hatenadiary.com/entry/2020/04/28/223738 https://sumita-m.hatenadiary.com/entry/2020/05/09/094358 https://sumita-m.hatenadiary.com/entry/2020/05/18/133546 https://sumita-m.hatenadiary.com/entry/2020/05/19/162116 https://sumita-m.hatenadiary.com/entry/2020/05/23/090836 https://sumita-m.hatenadiary.com/entry/2020/12/06/083221