<http://webisa.webdatacommons.org/426390454>	<http://www.w3.org/ns/prov#wasQuotedFrom>	<wordpress.com> .
<http://webisa.webdatacommons.org/prov/385233034>	<http://www.w3.org/ns/prov#wasDerivedFrom>	<http://webisa.webdatacommons.org/426390454> .
<http://webisa.webdatacommons.org/426390454>	<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>	<http://www.w3.org/ns/prov#Entity> .
<http://webisa.webdatacommons.org/426390454>	<http://www.w3.org/ns/prov#value>	"Checking whether a number is valid is a matter of checking if the length and last digit are correct." .