_:n83b698bb8e37439aa82dc4c20072c362xb1
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://naokirin.hatenablog.com/archive/category/%E3%83%97%E3%83%AD%E3%82%B0%E3%83%A9%E3%83%9F%E3%83%B3%E3%82%B0-OCaml>