About: http://webisa.webdatacommons.org/397417291

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	While the optical system including a cylindrical lens has been described as an embodiment, it will be noted that the present invention may be embodied into an optical system having no cylindrical lens and a toroidal lens.
http://www.w3.org/ns/prov#wasQuotedFrom	google.co.uk