About: http://webisa.webdatacommons.org/176840809

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	In number theory, the Calkin???Wilf tree is a tree in which the vertices correspond 1-for-1 to the positive rational numbers.
http://www.w3.org/ns/prov#wasQuotedFrom	wikipedia.org