About: http://webisa.webdatacommons.org/197479752

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	Since nobody has said so, I will mention that the notion you describe is a particular case of the known --- but perhaps obscure --- concept of Guitart exact square.
http://www.w3.org/ns/prov#wasQuotedFrom	mathoverflow.net