*1:See also https://sumita-m.hatenadiary.com/entry/20160817/1471400786 https://sumita-m.hatenadiary.com/entry/2020/01/23/123241 https://sumita-m.hatenadiary.com/entry/2020/02/20/022728 https://sumita-m.hatenadiary.com/entry/2020/02/21/140218 https://sumita-m.hatenadiary.com/entry/2020/03/05/130605 https://sumita-m.hatenadiary.com/entry/2020/03/07/094904
