About: http://webisa.webdatacommons.org/3034648

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	If this surface is not a plane, as is the case for example with walking sticks with a round cross-section, the laser beam cannot be focused on a single point in the matrix of material 10.
http://www.w3.org/ns/prov#wasQuotedFrom	freepatentsonline.com