[Pellet-users] Add subclass?

[jenny]

Hi!

I have created a new class and added it to the knowledge base:
ATermAppl c = ATermUtils.makeTermAppl( "c" );
reasoner.getKB().addClass(c);

How do I make this new class "c" a subclass of a class that already is in 
the knowledge base?
Can I somehow get classes in ATermAppl so I can use: 
"addSubClass(aterm.ATermAppl sub, aterm.ATermAppl sup)"?

Regards,
Jenny