About: http://webisa.webdatacommons.org/91358029

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 error you got is a result of trying to assign a const-iterator to an non-const iterator (it2).
http://www.w3.org/ns/prov#wasQuotedFrom	daniweb.com