<http://caligraph.org/ontology/1973_introduction>	<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>	<http://www.w3.org/2002/07/owl#Class> .
<http://caligraph.org/ontology/Computer-related_introduction_in_1973>	<http://www.w3.org/2000/01/rdf-schema#subClassOf>	<http://caligraph.org/ontology/1973_introduction> .
<http://caligraph.org/ontology/1973_introduction>	<http://www.w3.org/2000/01/rdf-schema#label>	"1973 introduction" .
<http://caligraph.org/ontology/1973_introduction>	<http://www.w3.org/ns/prov#wasDerivedFrom>	<http://en.wikipedia.org/wiki/Category:1973_introductions> .
<http://caligraph.org/ontology/Telecommunications-related_introduction_in_1973>	<http://www.w3.org/2000/01/rdf-schema#subClassOf>	<http://caligraph.org/ontology/1973_introduction> .
<http://caligraph.org/ontology/1973_introduction>	<http://www.w3.org/2000/01/rdf-schema#subClassOf>	<http://caligraph.org/ontology/Introduction> .
<http://caligraph.org/ontology/Train-related_introduction_in_1973>	<http://www.w3.org/2000/01/rdf-schema#subClassOf>	<http://caligraph.org/ontology/1973_introduction> .