About: http://webisa.webdatacommons.org/247669200

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	Visibly push-down languages are closed under all boolean operations, and problems such as inclusion, that are undecidable for context-free languages, are decidable for Vpl.
http://www.w3.org/ns/prov#wasQuotedFrom	psu.edu