Well, I'm afraid, I don't see into terms that much. I've found some definition in YaST doc that term is "symbol followed by list enclosed in brackets" ... So, what is empty term? Is it term without symbol and list (can I write something like this in YaST ?) or symbol followed by empty list or term equal to `Empty() ?

IsEmpty( false) -> false is correct in my POV (same case as IsEmpty( 0) )