About: http://webisa.webdatacommons.org/97047179

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	Solve[{p1==x y+x (w + z)+y (w + z), q==x+y, p==y+w+z, r==x+w+z}, {p1}, {x, y, w, z}] // Simplify or e.g. GroebnerBasis[{x y + x (w + z) + y (w + z), x + y - q, y + w + z - p, x + w + z - r}, {p, q, r}, {x, y, w, z}] // Simplify.
http://www.w3.org/ns/prov#wasQuotedFrom	stackexchange.com