*1:See also https://sumita-m.hatenadiary.com/entry/20091118/1258509143 https://sumita-m.hatenadiary.com/entry/20161009/1475940702 https://sumita-m.hatenadiary.com/entry/2019/09/11/102504 https://sumita-m.hatenadiary.com/entry/2020/02/12/125537 https://sumita-m.hatenadiary.com/entry/2020/03/09/132415 https://sumita-m.hatenadiary.com/entry/2020/04/10/102333 https://sumita-m.hatenadiary.com/entry/2020/06/07/161920 https://sumita-m.hatenadiary.com/entry/2020/07/23/140730
