Re: FDs and confluence

On Thu, Apr 13, 2006 at 12:07:53PM -0700, Iavor Diatchki wrote:

On 4/12/06, Claus Reinke wrote:

...

that's why Ross chose a fresh variable in FD range position: in the old translation, the class-based FD improvement rule no longer applies after reduction because there's only one C constraint left, and the instance-based FD improvement rule will only instantiate the 'b' or 'c' in the constraint with a fresh 'b_123', 'b_124', .., unrelated to 'b', 'c', or any previously generated variables in the constraint store.

I understand the reduction steps. Are you saying that the problem is that the two sets are not syntactically equal? To me this does not seem important: we just end up with two different ways to say the same thing (i.e., they are logically equivalent).

If c were mentioned in another constraint, they would not be equivalent.