<http://webisa.webdatacommons.org/prov/54451913>	<http://www.w3.org/ns/prov#wasDerivedFrom>	<http://webisa.webdatacommons.org/451619908> .
<http://webisa.webdatacommons.org/451619908>	<http://www.w3.org/ns/prov#value>	"Suppose that A is a subset of B. How can we show that B-complement is a subset of A-complement?" .
<http://webisa.webdatacommons.org/451619908>	<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>	<http://www.w3.org/ns/prov#Entity> .
<http://webisa.webdatacommons.org/451619908>	<http://www.w3.org/ns/prov#wasQuotedFrom>	<stackexchange.com> .