Re: Nulls, integrity, the closed world assumption and events
From: Cimode <cimode_at_hotmail.com>
Date: 8 Jan 2007 02:09:31 -0800
Message-ID: <1168250971.134073.316120_at_i15g2000cwa.googlegroups.com>
Date: 8 Jan 2007 02:09:31 -0800
Message-ID: <1168250971.134073.316120_at_i15g2000cwa.googlegroups.com>
David wrote:
> Consider the following relation
>
> person(P,M,F) :- person P has mother M, father F.
>
> By induction a non-empty
> database would have to be infinite.
A false premise makes all deductions coming from it false. Closed
World Assumption does not say anything about the number of element that
belong to a domain of values from which one attribute values are
derived. In the case of a *person* domain, the number of elements in
the set is certainly finite. Therefore, the number of propositions
involving person as an attribute is limited as well.
Received on Mon Jan 08 2007 - 11:09:31 CET