About: http://webisa.webdatacommons.org/336533117

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	As far as I am aware, in the 1970s, the US Patent Office did not demand to see a working prototype before granting a patent, especially if the patent related to a device based on accepted Engineering principles.
http://www.w3.org/ns/prov#wasQuotedFrom	wordpress.com