About: http://webisa.webdatacommons.org/88605214

Property	Value
http://www.w3.org/1999/02/22-rdf-syntax-ns#type	http://www.w3.org/ns/prov#Entity
http://www.w3.org/ns/prov#value	and the second part provides the library's users with a mechanism to make the above code work not only for char, int or other built-in type, but for they own types as well:
http://www.w3.org/ns/prov#wasQuotedFrom	boost.org