@prefix skos:	<http://www.w3.org/2004/02/skos/core#> .
@prefix isac:	<http://webisa.webdatacommons.org/concept/> .
isac:_cipher_	skos:broader	isac:caesar_cipher_ .
isac:affine_cipher_	skos:broader	isac:caesar_cipher_ .
isac:_rot13_	skos:broader	isac:caesar_cipher_ .