About: http://webisa.webdatacommons.org/146690168

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	To this end, the invention provides at least two zones of light, generated by at least one light source, said light zones sweeping the target plane and subtending between them a given angle or angles, in particular a right angle.
http://www.w3.org/ns/prov#wasQuotedFrom	google.com