*1:See eg. https://sumita-m.hatenadiary.com/entry/20091109/1257705586
*2:See also https://sumita-m.hatenadiary.com/entry/2019/08/20/073933 https://sumita-m.hatenadiary.com/entry/2020/03/19/023253 https://sumita-m.hatenadiary.com/entry/2020/05/09/103607 https://sumita-m.hatenadiary.com/entry/2020/07/22/153200 https://sumita-m.hatenadiary.com/entry/2020/07/25/215456 https://sumita-m.hatenadiary.com/entry/2020/07/28/234952 https://sumita-m.hatenadiary.com/entry/2020/09/08/101928 https://sumita-m.hatenadiary.com/entry/2020/09/16/122823 https://sumita-m.hatenadiary.com/entry/2020/09/18/022123 https://sumita-m.hatenadiary.com/entry/2020/11/06/143118 https://sumita-m.hatenadiary.com/entry/2020/11/07/090604 https://sumita-m.hatenadiary.com/entry/2020/11/19/131418