Re: RM formalism supporting partial information

David BL wrote:
...
>
> If you're working directly with the tuples, then in a way you're
> working at a more physical level than if you're using a difference
> operator to remove information. ...

I wasn't expecting that you'd say tuples are physical, not to any degree at all. For example, I don't see why one would take, nor need to take, D&D's tuple definition which uses a set of triples, and physically store it. But that tuple definition is certainly necessary for their logical set operations. Are you suggesting that information can be removed by other than a difference operator such as D&D's which is simply {original relation} <AND> ( <NOT> {relation to be "removed"})? Received on Sun Nov 18 2007 - 03:50:21 CET