Re: A different definition of MINUS, part 4
From: paul c <toledobythesea_at_oohay.ac>
Date: Fri, 09 Jan 2009 07:02:14 -0800
Message-ID: <nEJ9l.9$tD1.6_at_newsfe07.iad>
>
> Just a relation expressing all of what all is. In the suppliers/parts
> example, one might group parts from SP into a relation valued attribute
> and then compare that against the P relation projected on {P}
>
> I am unsure of the exact notation but something like:
>
> (SP{S,P} GROUP Parts{P} | Parts = P{P}){S}
>
Date: Fri, 09 Jan 2009 07:02:14 -0800
Message-ID: <nEJ9l.9$tD1.6_at_newsfe07.iad>
>> can be got without Forall, as long as we have projection. I gather >> that 'full relation' often means a cartesian product.
>
> Just a relation expressing all of what all is. In the suppliers/parts
> example, one might group parts from SP into a relation valued attribute
> and then compare that against the P relation projected on {P}
>
> I am unsure of the exact notation but something like:
>
> (SP{S,P} GROUP Parts{P} | Parts = P{P}){S}
>