*1:See also https://sumita-m.hatenadiary.com/entry/20160228/1456655841 https://sumita-m.hatenadiary.com/entry/2021/06/02/084828 https://sumita-m.hatenadiary.com/entry/2021/06/06/094703 https://sumita-m.hatenadiary.com/entry/2021/06/09/072915 https://sumita-m.hatenadiary.com/entry/2021/06/10/225318 https://sumita-m.hatenadiary.com/entry/2021/06/12/091601 https://sumita-m.hatenadiary.com/entry/2021/06/15/011430 https://sumita-m.hatenadiary.com/entry/2021/06/17/083030 https://sumita-m.hatenadiary.com/entry/2021/06/20/074653