Re: Universal Property

So, would a concrete proposal that we'd introduce a "owl:RoleThing"  
that is the superrole of all other roles? If so, for symmetry we  
should introduce the owl:RoleNothing (ok, better names, please!)  
(which would be easily definable by disjointness with owl:RoleThing).

Aside from expressivity benefits, this would be really nice for  
editors, IDEs, and debugging. I've had requests for unsatisfiable  
role checking and lots of people want a "top" role, if just for JTree  
nice layoutness.

Cheers,
Bijan.