_:vb56451	<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>	<http://www.w3.org/2002/07/owl#Restriction> .
_:vb56451	<http://www.w3.org/2002/07/owl#onProperty>	<http://www.w3.org/2002/12/cal/icalSpec#due> .
_:vb56451	<http://www.w3.org/2002/07/owl#minCardinality>	"0"^^<http://www.w3.org/2001/XMLSchema#integer> .