About: http://webisa.webdatacommons.org/43007401

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	A system according to claim 1, further including a flat refracting surface which is located at or near a position optically equivalent to said object and which is perpendicular to said optical axis.
http://www.w3.org/ns/prov#wasQuotedFrom	google.com