Re: Relation subset operators

From: <>
Date: Fri, 5 Jun 2009 12:25:14 -0700 (PDT)
Message-ID: <>

On 5 juin, 20:32, paul c <> wrote:
> wrote:
> > On 5 juin, 18:56, paul c <> wrote:
> >> wrote:
> ...
> > Question 8 (the one you mentionned): What are the total sales of
> > salesmen who sold ALL purple cars is a particular case of Question1
> > since all salesmen who sold ALL purple cars are the same than ALL
> > salesmen who have sold AT LEAST one purple car.  ...
> I believe, au contraire, that the answer is the same as the total sales
> of each salesman (assuming there never were any purple cars, which would
> be a shame IMO).  See "purple parts" in

For the moment, let's keep aggregating out of the equation. First, I want to make sure I understand correctly Question 8. The debunk link provided does not explain under what conditions a salesman, who'd be a part of a set of salesmen who have sold ALL purple cars, would NOT also be a salesman who sold AT LEAST one purple car. I would appreciate if you could give me one example clarifying the previous question ? Received on Fri Jun 05 2009 - 21:25:14 CEST

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