Re: more on delete from join

From: TroyK <>
Date: Thu, 27 Aug 2009 11:14:10 -0700 (PDT)
Message-ID: <>

On Aug 26, 3:51 pm, Tegiri Nenashi <> wrote:
> On Aug 26, 1:03 pm, paul c <> wrote:


> Stop right there. You were writing R UNION A, so R and A are relations
> (or predicates) and not propositions. Once again, some propositions
> are predicates (namely 0-ary ones), but most of them aren't!


In one of his dbdebunk papers (and probably in other writings), Date gives the following definition:
"A proposition is a predicate in which all variables are bound; ...". This doesn't to match with your statement above. What propositions are not predicates? Is there another notion to the term that Date is ignoring that you're using for this discussion?

TroyK Received on Thu Aug 27 2009 - 20:14:10 CEST

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