About: http://webisa.webdatacommons.org/231921078

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	To start with notice that eqns 1 and 2 represent each a 3D-plane whose intersection is a line (unless all $c_i$'s are equal).
http://www.w3.org/ns/prov#wasQuotedFrom	stackexchange.com