About: http://webisa.webdatacommons.org/398034547

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	Could also, if it is inconvenient to keep the trains in sync or not enough space to have them in both directions at once - just have a very heavy weight e.g. beneath the track that is programmed to accelerate in opposite direction.
http://www.w3.org/ns/prov#wasQuotedFrom	science20.com