*1:See also https://sumita-m.hatenadiary.com/entry/2020/01/26/110003 https://sumita-m.hatenadiary.com/entry/2020/02/03/090355 https://sumita-m.hatenadiary.com/entry/2020/02/17/131705 https://sumita-m.hatenadiary.com/entry/2020/04/29/112822 https://sumita-m.hatenadiary.com/entry/2020/06/10/085835 https://sumita-m.hatenadiary.com/entry/2020/06/11/094620