Re: MV Keys

From: vc <boston103_at_hotmail.com>
Date: 8 Mar 2006 05:22:40 -0800
Message-ID: <1141824160.347616.85480_at_i40g2000cwc.googlegroups.com>


Brian Selzer wrote:
[...]
> "x is 2" is a sentence; "y is 3" is a sentence.
> "x is 2 and y is 3" is also a sentence.

You are confused. "x is 2" is not a sentence in the contex of FOL. It's a predicate with a free variable which will become a sentence if you substitute a constant for x.

>Thus a tuple in a relation R{A, B, C} is the
> set of propositions {A has value 3, B has value 7, C has value 2}. The
> tuple itself also has a truth value, "A has value 3 and B has value 7 and C
> has value 2." which is a proposition in conjunctive normal form.

You are confused even more. A relation is simply an interpretation of some predicate (which is an element of a FOL language). A tuple is an element of such relation. Received on Wed Mar 08 2006 - 14:22:40 CET

Original text of this message