About: http://webisa.webdatacommons.org/149768360

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	Parallel curves : Two curves are parallel if every normal to one curve is a normal to the other curve and the distance between where the normals cut the two curves is a constant.
http://www.w3.org/ns/prov#wasQuotedFrom	st-and.ac.uk