> all right, I just looked at your problem once more, and believe it's
> abusive. An inheritance that is not an is-a relationship induces
> physical pain in this simple me. :-) So I guess the problem is
> actually somewhere else.

well we have to know if #is: is about testing inheritance, or more 
generally protocols. if it's for testing inheritance, all right my 
problem is not pertinent and I have no issues with #is: (only that it's 
maybe a little too much to call this #is:, then; it could be called 
#isSortOf: :)

best,

Stef