*1:See also https://sumita-m.hatenadiary.com/entry/20081029/1225281703 https://sumita-m.hatenadiary.com/entry/20120115/1326643979 https://sumita-m.hatenadiary.com/entry/20160113/1452654924 https://sumita-m.hatenadiary.com/entry/2019/10/21/130550 https://sumita-m.hatenadiary.com/entry/2020/02/23/134205 https://sumita-m.hatenadiary.com/entry/2020/07/03/105520 https://sumita-m.hatenadiary.com/entry/2020/10/08/091847 https://sumita-m.hatenadiary.com/entry/2020/12/27/192147 https://sumita-m.hatenadiary.com/entry/2021/06/04/025533 https://sumita-m.hatenadiary.com/entry/2021/06/25/130922
