Re: constraints in algebra instead of calculus

Vadim Tropashko wrote:
> I was little careless when translating my earlier post into this.
> Clearly the WHERE expression
>
> R WHERE B = B'
>
> doesn't make sence because B' is not a column of R. What I meant was
> join of R, which is a finite relation, with "B = B' " which is
> infinite relation. The result is still a finite relation. I suspect
> that the correct D&D syntax would be something like this
>
> EXTEND R WITH B' SUCH THAT B = B'
EXTEND R ADD (B AS B') (http://www.dcs.warwick.ac.uk/~hugh/TTM/APPXI.pdf, if you have any use for it.)

-- 
Jon