Hi,

> That seems backwards from the way OO inheritance is supposed to work.  
> You don't go from a more feature-rich case to a less feature-rich case 
> -- it's the other way around.

Of course it is -- that is precisely why inheritance is the wrong
formalism for my problem!  What I need is a "reverse inheritance"
formalism, where a fully defined data structure sits at the root,
and whose descendants are PRUNED versions of the parent.

If sound (and I let the theoreticians decide on that), such a
formalism would be an interesting solution to the type of problem
that originated this thread.

Cheers,
Dario



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