<https://eforum.idg.se/topic/141074-f%C3%B6rmodligen-ett-algebra-problem-eller/#comment-739590>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://eforum.idg.se/topic/141074-f%C3%B6rmodligen-ett-algebra-problem-eller/?tab=comments#comment-739590>