@prefix skos:	<http://www.w3.org/2004/02/skos/core#> .
@prefix isac:	<http://webisa.webdatacommons.org/concept/> .
isac:_end_	skos:broader	isac:null_string_ .
isac:_function_	skos:broader	isac:null_string_ .
isac:empty_string_	skos:broader	isac:null_string_ .