About: http://webisa.webdatacommons.org/14997388

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 another embodiment, one of the first and second surfaces is substantially convex or substantially concave, and the other of the surfaces is substantially flat.
http://www.w3.org/ns/prov#wasQuotedFrom	google.es