PropertyValue
http://www.w3.org/1999/02/22-rdf-syntax-ns#type
http://www.w3.org/ns/prov#value
  • Of four optical surfaces forming the prism member, two or three optical surfaces including two reflecting surfaces are each formed from a three-dimensional surface having only one plane of symmetry, and the remaining two or one surface is formed from a spherical surface, thereby imparting an image-forming ability to the prism member.
http://www.w3.org/ns/prov#wasQuotedFrom
  • google.com