*1:See also https://sumita-m.hatenadiary.com/entry/20140723/1406083089 https://sumita-m.hatenadiary.com/entry/2020/02/15/083534 https://sumita-m.hatenadiary.com/entry/2020/02/18/012709 https://sumita-m.hatenadiary.com/entry/2020/04/19/104243 https://sumita-m.hatenadiary.com/entry/2020/05/05/130104 https://sumita-m.hatenadiary.com/entry/2020/05/16/152546 https://sumita-m.hatenadiary.com/entry/2020/08/21/002209 https://sumita-m.hatenadiary.com/entry/2020/10/01/094838 https://sumita-m.hatenadiary.com/entry/2020/10/12/164435 https://sumita-m.hatenadiary.com/entry/2020/11/19/083125