About: http://webisa.webdatacommons.org/143830545

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 their difference is zero, then the principal curvatures are equal and it follows that the surface is a sphere or a plane.
http://www.w3.org/ns/prov#wasQuotedFrom	stackexchange.com