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On Jun 26, 1:48 pm, Jan Hidders <hidd..._at_gmail.com> wrote:
> (R(x,y) * []) + (R(x,y) * W)> (10) = R(x,y) * ([x,y] + W)
> (22) = [x,y] + (R(x,y) * W)
> (9) = ([x,y] + R(x,y)) * ([x,y] + W)
I don't think the axiom #9 (as written in one of your previous posts) is correct. First, it should be more restrictive than #8 and it looks less restrictive. Anyway, the first application of distributivity is correct. I doubt the second one. In the distributive law:
A + (B*C) = (A+B) * (A+C)
the attributes of B are required to be a superset of A, not subset. Received on Tue Jun 26 2007 - 16:31:21 CDT