*1:See also https://sumita-m.hatenadiary.com/entry/20070108/1168229799 https://sumita-m.hatenadiary.com/entry/20100907/1283879394 https://sumita-m.hatenadiary.com/entry/20150407/1428337714 https://sumita-m.hatenadiary.com/entry/20160828/1472399796 https://sumita-m.hatenadiary.com/entry/2019/09/07/080148 https://sumita-m.hatenadiary.com/entry/2020/10/11/010256
*2:See also https://sumita-m.hatenadiary.com/entry/20161002/1475427880
