set-valued values
From: paul c <toledobythesea_at_oohay.ac>
Date: Fri, 08 Dec 2006 00:22:39 GMT
Message-ID: <jf2eh.447133$R63.247965_at_pd7urf1no>
Another maybe crazy question - if instead of 'atomic values' (whatever that means) a relational engine (note for David, I've avoided using the term 'DBMS' !) expressed only values made up of sets, would the presence of the empty set in both true and false extensions create any problems? (I'm thinking that the relational requirement of attribute names means there is no problem, eg., the presence of empty sets is just an artifact of the mechanism that can usually be safely ignored.)
Date: Fri, 08 Dec 2006 00:22:39 GMT
Message-ID: <jf2eh.447133$R63.247965_at_pd7urf1no>
Another maybe crazy question - if instead of 'atomic values' (whatever that means) a relational engine (note for David, I've avoided using the term 'DBMS' !) expressed only values made up of sets, would the presence of the empty set in both true and false extensions create any problems? (I'm thinking that the relational requirement of attribute names means there is no problem, eg., the presence of empty sets is just an artifact of the mechanism that can usually be safely ignored.)
As for representation, sometimes such values can't be represented without access to other 'attributes', eg., values that are internal to an engine. My attitude (no reasoning involved I'm afraid to say) is that it's okay to give the builtin result 'true' in such cases. That way, the engine can proceed to manipulate the expression if further requests of made of it, concerning that result.
p Received on Fri Dec 08 2006 - 01:22:39 CET