@prefix skos:	<http://www.w3.org/2004/02/skos/core#> .
@prefix isac:	<http://webisa.webdatacommons.org/concept/> .
isac:_course_	skos:broader	isac:structural_difference_ .
isac:fuel_tank_	skos:broader	isac:structural_difference_ .
isac:_size_	skos:broader	isac:structural_difference_ .
isac:_scientist_	skos:broader	isac:structural_difference_ .