Re: more closed-world chatter

On May 5, 3:16 am, Marshall <marshall.spi..._at_gmail.com> wrote:

[snip]

> def pricedomain = set {1, 2};
> def anotherdomain = set {3};
>
> def R1 = set(price) [price : pricedomain] {(1)};
> def R2 = set(price) [price : anotherdomain] {(3)};
>
> def R = R1 & R2;
> ---
>
> At this point, what is the value of R?
>
> R = set(price) [price:pricedomain; price:anotherdomain] {};
>
> Since the union of pricedomain and anotherdomain is empty:

IMO it's confusing to talk about taking a "union of the constraints". In a sense you are aggregating them. I would call it an ANDing of constraints as boolean valued expressions, which leads to set intersections not unions. Received on Sat May 05 2007 - 10:00:25 CDT