<https://to-raku.com/tag/%E3%81%A4%E3%81%A4%E3%81%BF%E3%82%84%E3%81%8D/#breadcrumblist>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://to-raku.com/tag/%E3%81%A4%E3%81%A4%E3%81%BF%E3%82%84%E3%81%8D/>