Copyright © 2021 Akihiro Kuroiwa Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.3 or any later version published by the Free Software Foundation; with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A copy of the license is included in the section entitled “GNU Free Documentation License”.
Oct 21, 2021
Abstract
This article is a sequel to “A petition” in 2015.