Re: Guessing?

From: paul c <toledobysea_at_ac.ooyah>
Date: Tue, 08 Jul 2008 22:07:41 GMT
Message-ID: <NyRck.65245$Jx.43062@pd7urf1no>


Brian Selzer wrote:
> "paul c" <toledobysea_at_ac.ooyah> wrote in message
> news:33Ock.59297$kx.264_at_pd7urf3no...

>>> Brian Selzer wrote:
>>> ...
>>>> Consider the following statements:
>>>>
>>>> 1. Susan is an electrical engineer.
>>>> 2. Susan is a mechanical engineer.
>>>> 3. Susan is an electrical engineer or Susan is a mechanical engineer.
>>>> ...
>>
>> I have another question.  Suppose we have a database that involves only 
>> statement 3.  Just what does its extension look like?
>>

>
> Correctly formed, each extension of the database would consist of two
> relations: one for mechanical engineers and one for electrical engineers.
> There are three possible extensions:
>
> one where Susan is both an electrical engineer and a mechanical engineer,
>
> MechanicalEngineers {{Person:Susan}}
> ElectricalEngineers {{Person:Susan}};
> ...

Okay, now stop right there. (It is the case you originally gave, ie., statements 1 and 2 are both true.) What is the extension of 'statement' 3? Received on Tue Jul 08 2008 - 17:07:41 CDT

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